ambari-server/src/main/java/org/apache/ambari/server/controller/internal/BlueprintConfigurationProcessor.java

/*
 * Licensed to the Apache Software Foundation (ASF) under one
 * or more contributor license agreements.  See the NOTICE file
 * distributed with this work for additional information
 * regarding copyright ownership.  The ASF licenses this file
 * to you under the Apache License, Version 2.0 (the
 * "License"); you may not use this file except in compliance
 * with the License.  You may obtain a copy of the License at
 *
 *     http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 */

package org.apache.ambari.server.controller.internal;


import static java.util.stream.Collectors.groupingBy;
import static java.util.stream.Collectors.toSet;

import java.net.URI;
import java.net.URISyntaxException;
import java.util.ArrayList;
import java.util.Arrays;
import java.util.Collection;
import java.util.Collections;
import java.util.HashMap;
import java.util.HashSet;
import java.util.Iterator;
import java.util.LinkedHashSet;
import java.util.LinkedList;
import java.util.List;
import java.util.Map;
import java.util.Objects;
import java.util.Set;
import java.util.regex.Matcher;
import java.util.regex.Pattern;

import javax.annotation.Nullable;
import javax.validation.constraints.NotNull;

import org.apache.ambari.server.AmbariException;
import org.apache.ambari.server.state.Cluster;
import org.apache.ambari.server.state.ConfigHelper;
import org.apache.ambari.server.state.PropertyDependencyInfo;
import org.apache.ambari.server.state.StackId;
import org.apache.ambari.server.state.ValueAttributesInfo;
import org.apache.ambari.server.topology.AdvisedConfiguration;
import org.apache.ambari.server.topology.Blueprint;
import org.apache.ambari.server.topology.Cardinality;
import org.apache.ambari.server.topology.ClusterTopology;
import org.apache.ambari.server.topology.ConfigRecommendationStrategy;
import org.apache.ambari.server.topology.Configuration;
import org.apache.ambari.server.topology.HostGroup;
import org.apache.ambari.server.topology.HostGroupInfo;
import org.apache.ambari.server.topology.InvalidTopologyException;
import org.apache.ambari.server.topology.validators.NameNodeHaValidator;
import org.apache.ambari.server.topology.validators.UnitValidatedProperty;
import org.apache.commons.lang.StringUtils;
import org.apache.commons.lang3.tuple.Pair;
import org.slf4j.Logger;
import org.slf4j.LoggerFactory;

import com.google.common.annotations.VisibleForTesting;
import com.google.common.base.Preconditions;
import com.google.common.base.Predicates;
import com.google.common.base.Strings;
import com.google.common.collect.ImmutableList;
import com.google.common.collect.ImmutableMap;
import com.google.common.collect.ImmutableSet;
import com.google.common.collect.Maps;
import com.google.common.collect.Sets;

/**
 * Updates configuration properties based on cluster topology.  This is done when exporting
 * a blueprint and when a cluster is provisioned via a blueprint.
 */
public class BlueprintConfigurationProcessor {

  private static final Logger LOG = LoggerFactory.getLogger(BlueprintConfigurationProcessor.class);

  private final static String COMMAND_RETRY_ENABLED_PROPERTY_NAME = "command_retry_enabled";

  private final static String COMMANDS_TO_RETRY_PROPERTY_NAME = "commands_to_retry";

  private final static String COMMAND_RETRY_MAX_TIME_IN_SEC_PROPERTY_NAME = "command_retry_max_time_in_sec";

  private final static String COMMAND_RETRY_ENABLED_DEFAULT = "true";

  private final static String COMMANDS_TO_RETRY_DEFAULT = "INSTALL,START";

  private final static String COMMAND_RETRY_MAX_TIME_IN_SEC_DEFAULT = "600";

  private final static String CLUSTER_ENV_CONFIG_TYPE_NAME = "cluster-env";

  private final static String HBASE_SITE_HBASE_COPROCESSOR_MASTER_CLASSES = "hbase.coprocessor.master.classes";
  private final static String HBASE_SITE_HBASE_COPROCESSOR_REGION_CLASSES = "hbase.coprocessor.region.classes";

  private final static String HAWQ_SITE_HAWQ_STANDBY_ADDRESS_HOST = "hawq_standby_address_host";
  private final static String HAWQSTANDBY = "HAWQSTANDBY";

  private final static String HDFS_HA_INITIAL_CONFIG_TYPE = CLUSTER_ENV_CONFIG_TYPE_NAME;
  private final static String HDFS_ACTIVE_NAMENODE_PROPERTY_NAME = "dfs_ha_initial_namenode_active";
  private final static String HDFS_STANDBY_NAMENODE_PROPERTY_NAME = "dfs_ha_initial_namenode_standby";
  private final static String HDFS_ACTIVE_NAMENODE_SET_PROPERTY_NAME = "dfs_ha_initial_namenode_active_set";
  private final static String HDFS_STANDBY_NAMENODE_SET_PROPERTY_NAME = "dfs_ha_initial_namenode_standby_set";

  private final static String HDFS_HA_INITIAL_CLUSTER_ID_PROPERTY_NAME = "dfs_ha_initial_cluster_id";
  private final static Set<String> HDFS_HA_INITIAL_PROPERTIES = ImmutableSet.of(
      HDFS_ACTIVE_NAMENODE_PROPERTY_NAME, HDFS_ACTIVE_NAMENODE_SET_PROPERTY_NAME,
      HDFS_STANDBY_NAMENODE_PROPERTY_NAME, HDFS_STANDBY_NAMENODE_SET_PROPERTY_NAME,
      HDFS_HA_INITIAL_CLUSTER_ID_PROPERTY_NAME);

  /**
   * These properties are only required during deployment, and should be removed afterwards.
   */
  public static final Map<String, Set<String>> TEMPORARY_PROPERTIES_FOR_CLUSTER_DEPLOYMENT = ImmutableMap.of(
    HDFS_HA_INITIAL_CONFIG_TYPE, HDFS_HA_INITIAL_PROPERTIES
  );

  private final static String HADOOP_ENV_CONFIG_TYPE_NAME = "hadoop-env";
  private final static String RANGER_TAGSYNC_SITE_CONFIG_TYPE_NAME = "ranger-tagsync-site";
  private static final String LOCALHOST = "localhost";


  /**
   * Single host topology updaters
   */
  protected static final Map<String, Map<String, PropertyUpdater>> singleHostTopologyUpdaters =
    new HashMap<>();

  /**
   * Multi host topology updaters
   */
  private static final Map<String, Map<String, PropertyUpdater>> multiHostTopologyUpdaters =
    new HashMap<>();

  /**
   * Database host topology updaters
   */
  private static final Map<String, Map<String, PropertyUpdater>> dbHostTopologyUpdaters =
    new HashMap<>();

  /**
   * Updaters for properties which need 'm' appended
   */
  private static final Map<String, Map<String, PropertyUpdater>> mPropertyUpdaters =
    new HashMap<>();

  /**
   * Non topology related updaters
   */
  private static final Map<String, Map<String, PropertyUpdater>> nonTopologyUpdaters =
    new HashMap<>();

  /**
   * Updaters that preserve the original property value, functions
   * as a placeholder for DB-related properties that need to be
   * removed from export, but do not require an update during
   * cluster creation
   */
  private final Map<String, Map<String, PropertyUpdater>> removePropertyUpdaters =
    new HashMap<>();

  /**
   * Collection of all updaters
   */
  private static final Collection<Map<String, Map<String, PropertyUpdater>>> allUpdaters =
    new ArrayList<>();

  /**
   * Compiled regex for hostgroup token with port information.
   */
  private static final Pattern HOSTGROUP_PORT_REGEX = Pattern.compile("%HOSTGROUP::(\\S+?)%:?(\\d+)?");

  /**
   * Compiled regex for hostgroup token with port information.
   */
  private static final Pattern LOCALHOST_PORT_REGEX = Pattern.compile("localhost:?(\\d+)?");

  /**
   * Compiled regex for placeholder
   */
  private static final Pattern PLACEHOLDER = Pattern.compile("\\{\\{.*\\}\\}");

  /**
   * Special network address
   */
  private static final String BIND_ALL_IP_ADDRESS = "0.0.0.0";

  /**
   * Statically-defined set of properties that can support HA using a nameservice name
   *   in the configuration, rather than just a host name.
   *   This set also contains other HA properties that will be exported if the
   *   expected hostname information is not found.
   */
  private static final Set<String> configPropertiesWithHASupport =
    new HashSet<>(Arrays.asList("fs.defaultFS", "hbase.rootdir", "instance.volumes", "policymgr_external_url", "xasecure.audit.destination.hdfs.dir"));

  private static final Set<Pair<String, String>> PROPERTIES_FOR_HADOOP_PROXYUSER = ImmutableSet.of(
    Pair.of("oozie-env", "oozie_user"),
    Pair.of("hive-env", "hive_user"),
    Pair.of("hive-env", "webhcat_user"),
    Pair.of("hbase-env", "hbase_user"),
    Pair.of("falcon-env", "falcon_user")
  );
  private static final String HADOOP_PROXYUSER_HOSTS_FORMAT = "hadoop.proxyuser.%s.hosts";
  private static final String HADOOP_PROXYUSER_GROUPS_FORMAT = "hadoop.proxyuser.%s.groups";

  /**
   * Statically-defined list of filters to apply on property exports.
   * This will initially be used to filter out the Ranger Passwords, but
   * could be extended in the future for more generic purposes.
   */
  private PropertyFilter[] getExportPropertyFilters(Map<Long, Set<String>> authToLocalPerClusterMap)
  {
    return new PropertyFilter[] {
      new PasswordPropertyFilter(),
      new SimplePropertyNameExportFilter("tez.tez-ui.history-url.base", "tez-site"),
      new SimplePropertyNameExportFilter("admin_server_host", "kerberos-env"),
      new SimplePropertyNameExportFilter("kdc_hosts", "kerberos-env"),
      new SimplePropertyNameExportFilter("master_kdc", "kerberos-env"),
      new SimplePropertyNameExportFilter("realm", "kerberos-env"),
      new SimplePropertyNameExportFilter("kdc_type", "kerberos-env"),
      new SimplePropertyNameExportFilter("ldap-url", "kerberos-env"),
      new SimplePropertyNameExportFilter("container_dn", "kerberos-env"),
      new SimplePropertyNameExportFilter("domains", "krb5-conf"),
      new SimplePropertyNameExportFilter(HDFS_ACTIVE_NAMENODE_PROPERTY_NAME, HADOOP_ENV_CONFIG_TYPE_NAME),
      new SimplePropertyNameExportFilter(HDFS_STANDBY_NAMENODE_PROPERTY_NAME, HADOOP_ENV_CONFIG_TYPE_NAME),
      new SimplePropertyNameExportFilter(HDFS_ACTIVE_NAMENODE_SET_PROPERTY_NAME, HADOOP_ENV_CONFIG_TYPE_NAME),
      new SimplePropertyNameExportFilter(HDFS_STANDBY_NAMENODE_SET_PROPERTY_NAME, HADOOP_ENV_CONFIG_TYPE_NAME),
      new SimplePropertyNameExportFilter(HDFS_ACTIVE_NAMENODE_PROPERTY_NAME, HDFS_HA_INITIAL_CONFIG_TYPE),
      new SimplePropertyNameExportFilter(HDFS_STANDBY_NAMENODE_PROPERTY_NAME, HDFS_HA_INITIAL_CONFIG_TYPE),
      new SimplePropertyNameExportFilter(HDFS_ACTIVE_NAMENODE_SET_PROPERTY_NAME, HDFS_HA_INITIAL_CONFIG_TYPE),
      new SimplePropertyNameExportFilter(HDFS_STANDBY_NAMENODE_SET_PROPERTY_NAME, HDFS_HA_INITIAL_CONFIG_TYPE),
      new StackPropertyTypeFilter(),
      new KerberosAuthToLocalRulesFilter(authToLocalPerClusterMap)};
  }

  /**
   * Statically-defined list of filters to apply on cluster config
   * property updates.
   *
   * This will initially be used to filter out properties that do not
   * need to be set, due to a given dependency property not having
   * an expected value.
   *
   * The UI uses the Recommendations/StackAdvisor APIs to accomplish this, but
   * Blueprints will use filters in the short-term, and hopefully move to a more
   * unified approach in the next release.
   *
   * This filter approach will also be used to remove properties in a given component
   * that are not valid in a High-Availability deployment (example: HDFS NameNode HA).
   */
  private static final PropertyFilter[] clusterUpdatePropertyFilters =
    { new DependencyEqualsFilter("hbase.security.authorization", "hbase-site", "true"),
      new DependencyNotEqualsFilter("hive.server2.authentication", "hive-site", "NONE"),
      /* Temporary solution related to HBASE/Phoenix issue PHOENIX-3360, to remove hbase.rpc.controllerfactory
       * .class from hbase-site. */
      new ConditionalPropertyFilter("hbase-site", "hbase.rpc.controllerfactory.class",
        "org.apache.hadoop.hbase.ipc.controller.ServerRpcControllerFactory"),
      new HDFSNameNodeHAFilter(),
      new HawqHAFilter() };

  private ClusterTopology clusterTopology;


  public BlueprintConfigurationProcessor(ClusterTopology clusterTopology) {
    this.clusterTopology = clusterTopology;
    initRemovePropertyUpdaters();
  }

  public Map<String, Map<String, PropertyUpdater>> getRemovePropertyUpdaters() {
    return removePropertyUpdaters;
  }

  public void initRemovePropertyUpdaters() {

    if (containsHostFromHostGroups("oozie-site", "oozie.service.JPAService.jdbc.url")) {
      Map<String, PropertyUpdater> oozieSiteUpdaters = singleHostTopologyUpdaters.get("oozie-site");
      Map<String, PropertyUpdater> oozieEnvUpdaters = singleHostTopologyUpdaters.get("oozie-env");
      if (oozieSiteUpdaters == null) {
        oozieSiteUpdaters = new HashMap<>();
      }
      if (oozieEnvUpdaters == null) {
        oozieEnvUpdaters = new HashMap<>();
      }
      oozieEnvUpdaters.put("oozie_existing_mysql_host", new SingleHostTopologyUpdater("OOZIE_SERVER"));
      oozieEnvUpdaters.put("oozie_existing_oracle_host", new SingleHostTopologyUpdater("OOZIE_SERVER"));
      oozieEnvUpdaters.put("oozie_existing_postgresql_host", new SingleHostTopologyUpdater("OOZIE_SERVER"));
      oozieSiteUpdaters.put("oozie.service.JPAService.jdbc.url",  new SingleHostTopologyUpdater("OOZIE_SERVER"));

      singleHostTopologyUpdaters.put("oozie-env", oozieEnvUpdaters);
      singleHostTopologyUpdaters.put("oozie-site", oozieSiteUpdaters);
    } else {
      Map<String, PropertyUpdater> oozieEnvOriginalValueMap = new HashMap<>();
      Map<String, PropertyUpdater> oozieSiteOriginalValueMap = new HashMap<>();
      // register updaters for Oozie properties that may point to an external DB
      oozieEnvOriginalValueMap.put("oozie_existing_mysql_host", new OriginalValuePropertyUpdater());
      oozieEnvOriginalValueMap.put("oozie_existing_oracle_host", new OriginalValuePropertyUpdater());
      oozieEnvOriginalValueMap.put("oozie_existing_postgresql_host", new OriginalValuePropertyUpdater());
      oozieSiteOriginalValueMap.put("oozie.service.JPAService.jdbc.url", new OriginalValuePropertyUpdater());

      removePropertyUpdaters.put("oozie-env", oozieEnvOriginalValueMap);
      removePropertyUpdaters.put("oozie-site", oozieSiteOriginalValueMap);
    }

    Map<String, PropertyUpdater> hiveEnvOriginalValueMap = new HashMap<>();
    // register updaters for Hive properties that may point to an external DB
    hiveEnvOriginalValueMap.put("hive_existing_oracle_host", new OriginalValuePropertyUpdater());
    hiveEnvOriginalValueMap.put("hive_existing_mssql_server_2_host", new OriginalValuePropertyUpdater());
    hiveEnvOriginalValueMap.put("hive_existing_mssql_server_host", new OriginalValuePropertyUpdater());
    hiveEnvOriginalValueMap.put("hive_existing_postgresql_host", new OriginalValuePropertyUpdater());
    hiveEnvOriginalValueMap.put("hive_existing_mysql_host", new OriginalValuePropertyUpdater());

    removePropertyUpdaters.put("hive-env", hiveEnvOriginalValueMap);

  }

  private boolean containsHostFromHostGroups(String configType, String propertyName) {
    String propertyValue = clusterTopology.getConfiguration().getPropertyValue(configType, propertyName);
    if (StringUtils.isEmpty(propertyValue)) {
      return false;
    }
    // check fir bp import
    Matcher m = HostGroup.HOSTGROUP_REGEX.matcher(propertyValue);
    if (m.find()) {
      return true;
    }

    // check for bp export
    for (HostGroupInfo groupInfo : clusterTopology.getHostGroupInfo().values()) {
      Collection<String> hosts = groupInfo.getHostNames();
      for (String host : hosts) {
        if (propertyValue.contains(host)) {
          return true;
        }
      }
    }
    return false;
  }

  public Set<String> getRequiredHostGroups() {
    Set<String> requiredHostGroups = new HashSet<>();
    Collection<Map<String, Map<String, PropertyUpdater>>> updaters = createCollectionOfUpdaters();

    // Iterate all registered updaters and collect host groups referenced by related properties and
    // extracted by the updaters
    for (Map<String, Map<String, PropertyUpdater>> updaterMap : updaters) {
      for (Map.Entry<String, Map<String, PropertyUpdater>> entry : updaterMap.entrySet()) {
        String type = entry.getKey();
        for (Map.Entry<String, PropertyUpdater> updaterEntry : entry.getValue().entrySet()) {
          String propertyName = updaterEntry.getKey();
          PropertyUpdater updater = updaterEntry.getValue();

          // cluster scoped configuration which also includes all default and BP properties
          Map<String, Map<String, String>> clusterProps = clusterTopology.getConfiguration().getFullProperties();
          Map<String, String> typeMap = clusterProps.get(type);
          if (typeMap != null && typeMap.containsKey(propertyName) && typeMap.get(propertyName) != null) {
            requiredHostGroups.addAll(updater.getRequiredHostGroups(
              propertyName, typeMap.get(propertyName), clusterProps, clusterTopology));
          }

          // host group configs
          for (HostGroupInfo groupInfo : clusterTopology.getHostGroupInfo().values()) {
            Map<String, Map<String, String>> hgConfigProps = groupInfo.getConfiguration().getProperties();
            Map<String, String> hgTypeMap = hgConfigProps.get(type);
            if (hgTypeMap != null && hgTypeMap.containsKey(propertyName)) {
              requiredHostGroups.addAll(updater.getRequiredHostGroups(
                propertyName, hgTypeMap.get(propertyName), hgConfigProps, clusterTopology));
            }
          }
        }
      }
    }

    // Iterate through all user defined properties (blueprint + cluster template only, no stack defaults) that do not
    // have a registered updater. These properties can reference host groups too which should be extracted by the default
    // updater
    Set<Pair<String, String>> propertiesWithUpdaters = getAllPropertiesWithUpdaters(updaters);

    // apply default updater on cluster config
    Map<String, Map<String, String>> userDefinedClusterProperties = clusterTopology.getConfiguration().getFullProperties(1);
    addRequiredHostgroupsByDefaultUpdater(userDefinedClusterProperties, propertiesWithUpdaters, requiredHostGroups);
    // apply default updater on hostgroup configs
    clusterTopology.getHostGroupInfo().values().stream().forEach(
      hostGroup -> {
        Configuration hostGroupConfig = hostGroup.getConfiguration();
        Map<String, Map<String, String>> hostGroupConfigProps = hostGroupConfig.getFullProperties(1);
        addRequiredHostgroupsByDefaultUpdater(hostGroupConfigProps, propertiesWithUpdaters, requiredHostGroups);
      });
    return requiredHostGroups;
  }

  /**
   * Adds required host groups based on user defined (in the blueprint or cluster template) configuration properties and
   * the default property updaters. Only those properties are considered which don't have a configured updater.
   * @param properties properties to scan for host group references
   * @param propertiesWithUpdaters properties in (configType, propertyName) which have a configured updater
   * @param hostGroupAccumulator collection to accumulate required host groups
   */
  private void addRequiredHostgroupsByDefaultUpdater(Map<String, Map<String, String>> properties,
                                                     Set<Pair<String, String>> propertiesWithUpdaters,
                                                     Set<String> hostGroupAccumulator) {
    properties.entrySet().forEach(
      configTypeEntry -> {
        String configType = configTypeEntry.getKey();
        configTypeEntry.getValue().entrySet().forEach(
          propertyEntry -> {
            String propertyName = propertyEntry.getKey();
            String oldValue = propertyEntry.getValue();
            if (!propertiesWithUpdaters.contains(Pair.of(configType, propertyName))) {
              Collection<String> requiredHostGroups =
                PropertyUpdater.defaultUpdater().getRequiredHostGroups(propertyName, oldValue, properties, clusterTopology);
              if (!requiredHostGroups.isEmpty()) {
                LOG.info("The following host groups are required by applying the default property updater on {}/{} property: {}",
                  configType, propertyName, requiredHostGroups);
              }
              hostGroupAccumulator.addAll(requiredHostGroups);
            }
          });
      });
  }


  /**
   * Update properties for cluster creation.  This involves updating topology related properties with
   * concrete topology information.
   *
   * @return Set of config type names that were updated by this update call
   */
  public Set<String> doUpdateForClusterCreate() throws ConfigurationTopologyException {
    Set<String> configTypesUpdated = new HashSet<>();
    Configuration clusterConfig = clusterTopology.getConfiguration();

    doRecommendConfigurations(clusterConfig, configTypesUpdated);

    // filter out any properties that should not be included, based on the dependencies
    // specified in the stacks, and the filters defined in this class
    doFilterPriorToClusterUpdate(clusterConfig, configTypesUpdated);

    Set<String> propertiesMoved = clusterConfig.moveProperties(HADOOP_ENV_CONFIG_TYPE_NAME, HDFS_HA_INITIAL_CONFIG_TYPE, HDFS_HA_INITIAL_PROPERTIES);
    if (!propertiesMoved.isEmpty()) {
      configTypesUpdated.add(HADOOP_ENV_CONFIG_TYPE_NAME);
      configTypesUpdated.add(HDFS_HA_INITIAL_CONFIG_TYPE);
    }

    // this needs to be called after doFilterPriorToClusterUpdate() to ensure that the returned
    // set of properties (copy) doesn't include the removed properties.  If an updater
    // removes a property other than the property it is registered for then we will
    // have an issue as it won't be removed from the clusterProps map as it is a copy.
    Map<String, Map<String, String>> clusterProps = clusterConfig.getFullProperties();
    doGeneralPropertyUpdatesForClusterCreate(clusterConfig, clusterProps, configTypesUpdated);

    //todo: lots of hard coded HA rules included here
    if (clusterTopology.isNameNodeHAEnabled()) {
      doNameNodeHAUpdateOnClusterCreation(clusterConfig, clusterProps, configTypesUpdated);
    }

    // Explicitly set any properties that are required but not currently provided in the stack definition.
    injectDefaults(clusterConfig, configTypesUpdated, clusterTopology.getBlueprint().getServices());
    setStackToolsAndFeatures(clusterConfig, configTypesUpdated);
    addExcludedConfigProperties(clusterConfig, configTypesUpdated, clusterTopology.getBlueprint().getStack());

    trimProperties(clusterConfig, clusterTopology);

    return configTypesUpdated;
  }

  /**
   * Update Namenode HA properties during cluster creation
   * @throws ConfigurationTopologyException
   */
  private void doNameNodeHAUpdateOnClusterCreation(Configuration clusterConfig,
                                                   Map<String, Map<String, String>> clusterProps,
                                                   Set<String> configTypesUpdated) throws ConfigurationTopologyException {

    final Collection<String> nnHosts = clusterTopology.getHostAssignmentsForComponent("NAMENODE");

    // external namenodes
    if (nnHosts.isEmpty()) {
      LOG.info("NAMENODE HA is enabled but there are no NAMENODE components in the cluster. Assuming external name nodes.");
      // need to redo validation here as required information (explicit hostnames for some host groups) may have been
      // missing by the time the ClusterTopology object was validated
      try {
        new NameNodeHaValidator().validateExternalNamenodeHa(clusterTopology);
      }
      catch (InvalidTopologyException ex) {
        throw new ConfigurationTopologyException(ex.getMessage(), ex);
      }
      return;
    }

    // add "dfs.internal.nameservices" if it's not specified
    Map<String, String> hdfsSiteConfig = clusterConfig.getFullProperties().get("hdfs-site");
    String nameservices = hdfsSiteConfig.get("dfs.nameservices");
    String int_nameservices = hdfsSiteConfig.get("dfs.internal.nameservices");
    if(int_nameservices == null && nameservices != null) {
      clusterConfig.setProperty("hdfs-site", "dfs.internal.nameservices", nameservices);
    }

    // parse out the nameservices value
    String[] parsedNameServices = parseNameServices(hdfsSiteConfig);

    // if a single nameservice is configured (default HDFS HA deployment)
    if (parsedNameServices.length == 1) {
      LOG.info("Processing a single HDFS NameService, which indicates a default HDFS NameNode HA deployment");
      // if the active/standby namenodes are not specified, assign them automatically
      if (! isNameNodeHAInitialActiveNodeSet(clusterProps) && ! isNameNodeHAInitialStandbyNodeSet(clusterProps)) {
        if (nnHosts.size() == 1) { // can't be 0 as in that case was handled above
          throw new ConfigurationTopologyException("NAMENODE HA requires at least two hosts running NAMENODE but there is " +
            "only one: " + nnHosts.iterator().next());
        }

        // set the properties that configure which namenode is active,
        // and which is a standby node in this HA deployment
        Iterator<String> nnHostIterator = nnHosts.iterator();
        clusterConfig.setProperty(HDFS_HA_INITIAL_CONFIG_TYPE, HDFS_ACTIVE_NAMENODE_PROPERTY_NAME, nnHostIterator.next());
        clusterConfig.setProperty(HDFS_HA_INITIAL_CONFIG_TYPE, HDFS_STANDBY_NAMENODE_PROPERTY_NAME, nnHostIterator.next());

        configTypesUpdated.add(HDFS_HA_INITIAL_CONFIG_TYPE);
      }
    } else {
      if (!isPropertySet(clusterProps, HDFS_HA_INITIAL_CONFIG_TYPE, HDFS_ACTIVE_NAMENODE_SET_PROPERTY_NAME) && !isPropertySet(clusterProps, HDFS_HA_INITIAL_CONFIG_TYPE, HDFS_STANDBY_NAMENODE_SET_PROPERTY_NAME)) {        // multiple nameservices indicates an HDFS NameNode Federation install
        // process each nameservice to determine the active/standby nodes
        LOG.info("Processing multiple HDFS NameService instances, which indicates a NameNode Federation deployment");
        if (parsedNameServices.length > 1) {
          Set<String> activeNameNodeHostnames = new HashSet<>();
          Set<String> standbyNameNodeHostnames = new HashSet<>();

          for (String nameService : parsedNameServices) {
            List<String> hostNames = new ArrayList<>();
            String[] nameNodes = parseNameNodes(nameService, hdfsSiteConfig);
            for (String nameNode : nameNodes) {
              // use the HA rpc-address property to obtain the NameNode hostnames
              String propertyName = "dfs.namenode.rpc-address." + nameService + "." + nameNode;
              String propertyValue = hdfsSiteConfig.get(propertyName);
              if (propertyValue == null) {
                throw new ConfigurationTopologyException("NameNode HA property = " + propertyName + " is not found in the cluster config.  This indicates an error in configuration for HA/Federated clusters.  " +
                  "Please recheck the HDFS configuration and try this deployment again");
              }

              String hostName = propertyValue.split(":")[0];
              hostNames.add(hostName);
            }

            if (hostNames.size() < 2) {
              throw new ConfigurationTopologyException("NAMENODE HA for nameservice = " + nameService + " requires at least 2 hosts running NAMENODE but there are: " +
                hostNames.size() + " Hosts: " + hostNames);
            } else {
              // by default, select the active and standby namenodes for this nameservice
              // using the first two hostnames found
              // since HA is assumed, there should only be two NameNodes deployed per NameService
              activeNameNodeHostnames.add(hostNames.get(0));
              standbyNameNodeHostnames.add(hostNames.get(1));
            }
          }

          // set the properties what configure the NameNode Active/Standby status for each nameservice
          if (!activeNameNodeHostnames.isEmpty() && !standbyNameNodeHostnames.isEmpty()) {
            clusterConfig.setProperty(HDFS_HA_INITIAL_CONFIG_TYPE, HDFS_ACTIVE_NAMENODE_SET_PROPERTY_NAME, String.join(",", activeNameNodeHostnames));
            clusterConfig.setProperty(HDFS_HA_INITIAL_CONFIG_TYPE, HDFS_STANDBY_NAMENODE_SET_PROPERTY_NAME, String.join(",", standbyNameNodeHostnames));

            // also set the clusterID property, required for Federation installs of HDFS
            if (!isPropertySet(clusterProps, HDFS_HA_INITIAL_CONFIG_TYPE, HDFS_HA_INITIAL_CLUSTER_ID_PROPERTY_NAME)) {
              clusterConfig.setProperty(HDFS_HA_INITIAL_CONFIG_TYPE, HDFS_HA_INITIAL_CLUSTER_ID_PROPERTY_NAME, getClusterName());
            }

            configTypesUpdated.add(HDFS_HA_INITIAL_CONFIG_TYPE);
          } else {
            LOG.warn("Error in processing the set of active/standby namenodes in this federated cluster, please check hdfs-site configuration");
          }
          // Need to configure ranger-tagsync-site properties, when Ranger-HDFS plugin is enabled
          doTagSyncSiteUpdateForNamenodeNFederationEnabledOnClusterCreation(clusterConfig, clusterProps, configTypesUpdated);
        }
      }
    }
  }

  /**
   * Update ranger-tagsync-site properties when NN Federation is enabled and Ranger-HDFS plugin is enabled
   * @throws ConfigurationTopologyException
   */
  private void doTagSyncSiteUpdateForNamenodeNFederationEnabledOnClusterCreation(Configuration clusterConfig,
                                                                    Map<String, Map<String, String>> clusterProps,
                                                                    Set<String> configTypesUpdated) throws ConfigurationTopologyException {
    Map<String, String> hdfsSiteConfig = clusterConfig.getFullProperties().get("hdfs-site");
    // parse out the nameservices value
    String[] parsedNameServices = parseNameServices(hdfsSiteConfig);
    String clusterName = getClusterName();

    // Getting configuration and properties for adding configurations to ranger-tagsync-site
    boolean isRangerHDFSPluginEnabled =  false;
    String rangerHDFSPluginServiceName = "";

    String atlasServerComponentName = "ATLAS_SERVER";
    String rangerAdminComponentName = "RANGER_ADMIN";
    String rangerTagsyncComponentName = "RANGER_TAGSYNC";
    boolean isRangerAdminToBeInstalled = (clusterTopology.getHostGroupsForComponent(rangerAdminComponentName).size() >= 1);
    boolean isRangerTagsyncToBeInstalled = (clusterTopology.getHostGroupsForComponent(rangerTagsyncComponentName).size() >= 1);
    boolean isAtlasServerToBeInstalled = (clusterTopology.getHostGroupsForComponent(atlasServerComponentName).size() >= 1);
    if (isRangerAdminToBeInstalled) {
      Map<String, String> rangerHDFSPluginProperties = clusterProps.get("ranger-hdfs-plugin-properties");
      String rangerHDFSPluginEnabledValue = rangerHDFSPluginProperties.getOrDefault("ranger-hdfs-plugin-enabled","No");
      isRangerHDFSPluginEnabled = ("yes".equalsIgnoreCase(rangerHDFSPluginEnabledValue));
      Map<String, String> rangerHDFSSecurityConfig = clusterProps.get("ranger-hdfs-security");
      rangerHDFSPluginServiceName = rangerHDFSSecurityConfig.get("ranger.plugin.hdfs.service.name");
    }

    boolean isTagsyncPropertyConfigurationRequired = ( isRangerAdminToBeInstalled && isRangerTagsyncToBeInstalled &&
                                                       isAtlasServerToBeInstalled && isRangerHDFSPluginEnabled );

    Map<String, String> coreSiteConfig = clusterProps.get("core-site");
    String fsDefaultFSValue = coreSiteConfig.get("fs.defaultFS");
    String nameServiceInFsDefaultFSConfig="";

    if (isTagsyncPropertyConfigurationRequired && "{{repo_name}}".equalsIgnoreCase(rangerHDFSPluginServiceName)) {
      rangerHDFSPluginServiceName = clusterName + "_hadoop";
    }
    // If blueprint configuration has multiple nameservices, indicating NN-Federation is enabled
    if (parsedNameServices.length > 1 && isTagsyncPropertyConfigurationRequired) {
      for (String nameService : parsedNameServices) {
        // Adding configurations for Ranger-Tagsync to map Ranger HDFS service for Atlas Tagsync
        String tagsyncNameserviceMappingProperty   = "ranger.tagsync.atlas.hdfs.instance." + clusterName + ".nameservice." + nameService + ".ranger.service";
        String updatedRangerHDFSPluginServiceName = rangerHDFSPluginServiceName + "_" + nameService;
        clusterConfig.setProperty(RANGER_TAGSYNC_SITE_CONFIG_TYPE_NAME, tagsyncNameserviceMappingProperty, updatedRangerHDFSPluginServiceName);
        try {
          URI fsDefaultFSURI = new URI(fsDefaultFSValue);
          String fsDefaultFSNameService = fsDefaultFSURI.getHost();
          if (fsDefaultFSNameService.contains(nameService)) {
            nameServiceInFsDefaultFSConfig = nameService;
          }
        } catch (URISyntaxException e) {
          LOG.error("Error occurred while parsing the defaultFS URI.", e);
        }
      }

      String rangerTagsyncAtlasNNServiceMappingProperty = "ranger.tagsync.atlas.hdfs.instance." + clusterName + ".ranger.service";
      String rangerTagsyncAtlasNNServiceName = rangerHDFSPluginServiceName + "_" + nameServiceInFsDefaultFSConfig;
      clusterConfig.setProperty(RANGER_TAGSYNC_SITE_CONFIG_TYPE_NAME, rangerTagsyncAtlasNNServiceMappingProperty, rangerTagsyncAtlasNNServiceName);
      configTypesUpdated.add(RANGER_TAGSYNC_SITE_CONFIG_TYPE_NAME);
    }
  }

  /**
   * Call registered updaters on cluster configuration + call default updater ({@link HostGroupUpdater#INSTANCE}) on
   * properties that were submitted in the blueprint or the cluster template and don't have a registered updater.
   */
  private void doGeneralPropertyUpdatesForClusterCreate(Configuration clusterConfig,
                                                        Map<String, Map<String, String>> clusterProps,
                                                        Set<String> configTypesUpdated) {
    // Iterate through the updaters and apply them in case applicable properties exist
    Collection<Map<String, Map<String, PropertyUpdater>>> updaters = createCollectionOfUpdaters();
    for (Map<String, Map<String, PropertyUpdater>> updaterMap : updaters) {
      for (Map.Entry<String, Map<String, PropertyUpdater>> entry : updaterMap.entrySet()) {
        final String configType = entry.getKey();
        for (Map.Entry<String, PropertyUpdater> updaterEntry : entry.getValue().entrySet()) {
          String propertyName = updaterEntry.getKey();
          PropertyUpdater updater = updaterEntry.getValue();

          // topo cluster scoped configuration which also includes all default and BP properties
          Map<String, String> typeMap = clusterProps.get(configType);
          if (typeMap != null && typeMap.containsKey(propertyName) && typeMap.get(propertyName) != null) {
            final String originalValue = typeMap.get(propertyName);
            final String updatedValue =
              updateValue(configType, propertyName, originalValue, updater, clusterProps, clusterConfig, configTypesUpdated, true);
            if (null == updatedValue) {
              continue;
            }
          }
          // host group configs
          for (HostGroupInfo groupInfo : clusterTopology.getHostGroupInfo().values()) {
            Configuration hgConfig = groupInfo.getConfiguration();
            Map<String, Map<String, String>> hgConfigProps = hgConfig.getFullProperties(1);
            Map<String, String> hgTypeMap = hgConfigProps.get(configType);
            if (hgTypeMap != null && hgTypeMap.containsKey(propertyName)) {
              final String originalValue = hgTypeMap.get(propertyName);
              updateValue(configType, propertyName, originalValue, updater, hgConfigProps, hgConfig, configTypesUpdated, true);
            }
          }
        }
      }
    }

    // Iterate through all user defined properties (blueprint + cluster template) and call the default updater for those
    // which don't have a configured updater. This is to make sure that %HOSTGROUP::name% tokens are replaced for each property
    Set<Pair<String, String>> propertiesWithUpdaters = getAllPropertiesWithUpdaters(updaters);
    // apply default updater on cluster config
    applyDefaultUpdater(clusterConfig, clusterConfig.getFullProperties(1), configTypesUpdated, propertiesWithUpdaters);
    // apply default updater on hostgroup configs
    clusterTopology.getHostGroupInfo().values().stream().forEach(
      hostGroup -> {
        Configuration hostGroupConfig = hostGroup.getConfiguration();
        Map<String, Map<String, String>> hostGroupConfigProps = hostGroupConfig.getFullProperties(1);
        applyDefaultUpdater(hostGroupConfig, hostGroupConfigProps, configTypesUpdated, propertiesWithUpdaters);
      });
  }

  /**
   * Calculates all properties that have registered updaters based on the received collection
   * @param updaters collection of all updaters
   * @return a set of all properties with updaters as (configType, propertyName) pairs.
   */
  private Set<Pair<String, String>> getAllPropertiesWithUpdaters(Collection<Map<String, Map<String, PropertyUpdater>>> updaters) {
    return updaters.stream().
      flatMap(map -> map.entrySet().stream()).
      flatMap(entry -> {
        String configType = entry.getKey();
        return entry.getValue().keySet().stream().map(propertyName -> Pair.of(configType, propertyName));
      }).
      collect(toSet());
  }

  /**
   * Applies the default updater ({@link HostGroupUpdater#INSTANCE}) for properties that don't have a registered updater.
   * This is to make sure that %HOSTGROUP::name% token replacements happen for all properties.
   */
  private void applyDefaultUpdater(Configuration configuration,
                                   Map<String, Map<String, String>> properties,
                                   Set<String> configTypesUpdated,
                                   Set<Pair<String, String>> propertiesWithUpdaters) {
    properties.entrySet().forEach(
      configTypeEntry -> {
        String configType = configTypeEntry.getKey();
        configTypeEntry.getValue().entrySet().forEach(
          propertyEntry -> {
            String propertyName = propertyEntry.getKey();
            if (!propertiesWithUpdaters.contains(Pair.of(configType, propertyName))) {
              String oldValue = propertyEntry.getValue();
              String newValue = updateValue(configType, propertyName, oldValue, PropertyUpdater.defaultUpdater(), properties,
                configuration, configTypesUpdated, false);
              if (!Objects.equals(oldValue, newValue)) {
                LOG.info("Property {}/{} was updated by the default updater from [{}] to [{}]",
                  configType, propertyName, oldValue, newValue);
              }
            }
          });
      });
  }

  /**
   * Encapsulates commonly repeated tasks around updating a configuration value during cluster creation.
   * @param configType the configuration type (e.g. hdfs-site)
   * @param propertyName the name of the property (e.g. dfs.namenode.name.dir)
   * @param oldValue the old value of the property
   * @param updater the property updater to use
   * @param allProps other properties to be considered by the updater
   * @param configuration configuration to update (cluster global config or hostgroup config)
   * @param configTypesUpdated set of updated config types (configType param will be added if updater changes the
   *                           value of the property)
   * @param alwaysUpdateConfig boolean to indicate whether the {@link Configuration} received as parameter should always
   *                           (except when new value is {@code null}) be updated or only in case the new value differs
   *                           from the original. (TODO: what is the reason for always updating the configuration?)
   * @return the updated value
   */
  private String updateValue(String configType,
                             String propertyName,
                             String oldValue,
                             PropertyUpdater updater,
                             Map<String, Map<String, String>> allProps,
                             Configuration configuration,
                             Set<String> configTypesUpdated,
                             boolean alwaysUpdateConfig) {
    String newValue = updater.updateForClusterCreate(propertyName, oldValue, allProps, clusterTopology);
    if (null != newValue) {
      if (!newValue.equals(oldValue)) {
        configTypesUpdated.add(configType);
      }
      if (!newValue.equals(oldValue) || alwaysUpdateConfig) {
        configuration.setProperty(configType, propertyName, newValue);
      }
    }
    return newValue;
  }


  private String getClusterName() throws ConfigurationTopologyException {
    String clusterNameToReturn = null;
    try {
      clusterNameToReturn = clusterTopology.getAmbariContext().getClusterName(clusterTopology.getClusterId());
    } catch (AmbariException e) {
      throw new ConfigurationTopologyException("Cluster name could not obtained, this may indicate a deployment or configuration error.", e);
    }

    if (clusterNameToReturn == null) {
      throw new ConfigurationTopologyException("Cluster name could not obtained, this may indicate a deployment or configuration error.");
    }

    return clusterNameToReturn;
  }

  private void trimProperties(Configuration clusterConfig, ClusterTopology clusterTopology) {
    Blueprint blueprint = clusterTopology.getBlueprint();
    Stack stack = blueprint.getStack();

    Map<String, Map<String, String>> configTypes = clusterConfig.getFullProperties();
    for (String configType : configTypes.keySet()) {
      Map<String,String> properties = configTypes.get(configType);
      for (String propertyName : properties.keySet()) {
        trimPropertyValue(clusterConfig, stack, configType, properties, propertyName);
      }
    }
  }

  private void trimPropertyValue(Configuration clusterConfig, Stack stack, String configType, Map<String, String> properties, String propertyName) {
    if (propertyName != null && properties.get(propertyName) != null) {

      TrimmingStrategy trimmingStrategy =
        PropertyValueTrimmingStrategyDefiner.defineTrimmingStrategy(stack, propertyName, configType);
      String oldValue = properties.get(propertyName);
      String newValue = trimmingStrategy.trim(oldValue);

      if (!newValue.equals(oldValue)){
        LOG.debug("Changing value for config {} property {} from [{}] to [{}]", configType, propertyName, oldValue, newValue);
        clusterConfig.setProperty(configType, propertyName, newValue);
      }
    }
  }

  /**
   * Returns true if property should be retained with default value instead of deleting
   * TODO: This is a temporary work-around till BP integrates with stack advisor
   * @param propertyName
   * @return
   */
  private static boolean shouldPropertyBeStoredWithDefault(String propertyName) {
    if (!StringUtils.isBlank(propertyName) &&
      (HBASE_SITE_HBASE_COPROCESSOR_MASTER_CLASSES.equals(propertyName) ||
        HBASE_SITE_HBASE_COPROCESSOR_REGION_CLASSES.equals(propertyName))) {
      return true;
    }

    return false;
  }

  /**
   * Update properties for blueprint export.
   * This involves converting concrete topology information to host groups.
   */
  public void doUpdateForBlueprintExport(BlueprintExportType exportType) {
    // HA configs are only processed in cluster configuration, not HG configurations
    if (clusterTopology.isNameNodeHAEnabled()) {
      doNameNodeHAUpdate();
    }

    if (clusterTopology.isYarnResourceManagerHAEnabled()) {
      doYarnResourceManagerHAUpdate();
    }

    if (isOozieServerHAEnabled(clusterTopology.getConfiguration().getFullProperties())) {
      doOozieServerHAUpdate();
    }

    Collection<Configuration> allConfigs = new ArrayList<>();
    Configuration clusterConfig = clusterTopology.getConfiguration();
    allConfigs.add(clusterConfig);
    for (HostGroupInfo groupInfo : clusterTopology.getHostGroupInfo().values()) {
      Configuration hgConfiguration = groupInfo.getConfiguration();
      if (! hgConfiguration.getFullProperties(1).isEmpty()) {
        // create new configuration which only contains properties specified in host group and BP host group
        allConfigs.add(new Configuration(hgConfiguration.getProperties(), null,
          new Configuration(hgConfiguration.getParentConfiguration().getProperties(), null)));
      }
    }

    for (Configuration configuration : allConfigs) {
      doSingleHostExportUpdate(singleHostTopologyUpdaters, configuration);
      doSingleHostExportUpdate(dbHostTopologyUpdaters, configuration);

      doMultiHostExportUpdate(multiHostTopologyUpdaters, configuration);

      doNonTopologyUpdate(nonTopologyUpdaters, configuration);

      doRemovePropertyExport(removePropertyUpdaters, configuration);

      doFilterPriorToExport(configuration);
    }

    Blueprint blueprint = clusterTopology.getBlueprint();
    applyTypeSpecificFilter(exportType, clusterConfig, blueprint.getStack().getConfiguration(), blueprint.getServices());
  }

  @VisibleForTesting
  void applyTypeSpecificFilter(BlueprintExportType exportType, Configuration clusterConfig, Configuration stackConfig, Collection<String> services) {
    if (exportType == BlueprintExportType.MINIMAL) {
      // convert back to suffix-less form, to allow comparing to defaults
      doNonTopologyUpdate(mPropertyUpdaters, clusterConfig);
    }

    injectDefaults(stackConfig, new HashSet<>(), services);
    exportType.filter(clusterConfig, stackConfig);
  }

  /**
   * This method iterates over the properties passed in, and applies a
   * list of filters to the properties.
   *
   * If any filter implementations indicate that the property should
   * not be included in a collection (a Blueprint export in this case),
   * then the property is removed prior to the export.
   *
   * @param configuration  configuration being processed
   */
  private void doFilterPriorToExport(Configuration configuration) {
    Map<String, Map<String, String>> properties = configuration.getFullProperties();
    Map<Long, Set<String>> authToLocalPerClusterMap = null;
    try {
      String clusterName = clusterTopology.getAmbariContext().getClusterName(clusterTopology.getClusterId());
      Cluster cluster = clusterTopology.getAmbariContext().getController().getClusters().getCluster(clusterName);
      authToLocalPerClusterMap = new HashMap<>();
      authToLocalPerClusterMap.put(Long.valueOf(clusterTopology.getClusterId()), clusterTopology.getAmbariContext().getController().getKerberosHelper().getKerberosDescriptor(cluster, false).getAllAuthToLocalProperties());
    } catch (AmbariException e) {
      LOG.error("Error while getting authToLocal properties. ", e);
    }
    PropertyFilter [] exportPropertyFilters = getExportPropertyFilters(authToLocalPerClusterMap);
    for (Map.Entry<String, Map<String, String>> configEntry : properties.entrySet()) {
      String type = configEntry.getKey();
      try {
        clusterTopology.getBlueprint().getStack().getServiceForConfigType(type);
      } catch (IllegalArgumentException illegalArgumentException) {
        LOG.error(new StringBuilder(String.format("Error encountered while trying to obtain the service name for config type [%s]. ", type))
          .append("Further processing on this config type will be skipped. ")
          .append("This usually means that a service's definitions have been manually removed from the Ambari stack definitions. ")
          .append("If the stack definitions have not been changed manually, this may indicate a stack definition error in Ambari. ").toString(), illegalArgumentException);
        continue;
      }
      Map<String, String> typeProperties = configEntry.getValue();

      for (Map.Entry<String, String> propertyEntry : typeProperties.entrySet()) {
        String propertyName = propertyEntry.getKey();
        String propertyValue = propertyEntry.getValue();
        if (shouldPropertyBeExcludedForBlueprintExport(propertyName, propertyValue, type, clusterTopology, exportPropertyFilters)) {
          configuration.removeProperty(type, propertyName);
        }
      }
    }
  }

  private void doFilterPriorToClusterUpdate(Configuration configuration, Set<String> configTypesUpdated) {
    // getFullProperties returns a copy so changes to it are not reflected in config properties
    Map<String, Map<String, String>> properties = configuration.getFullProperties();
    for (Map.Entry<String, Map<String, String>> configEntry : properties.entrySet()) {
      String configType = configEntry.getKey();
      Map<String, String> configPropertiesPerType = configEntry.getValue();

      for (Map.Entry<String, String> propertyEntry : configPropertiesPerType.entrySet()) {
        String propName = propertyEntry.getKey();
        if (shouldPropertyBeExcludedForClusterUpdate(propName, propertyEntry.getValue(), configType, clusterTopology)) {
          configuration.removeProperty(configType, propName);
          configTypesUpdated.add(configType);
        }
      }
    }
  }

  /**
   * Update configuration properties from recommended configurations of the stack advisor based on
   * {@link ConfigRecommendationStrategy}
   * @param configuration configuration being processed
   * @param configTypesUpdated updated config types
   */
  private void doRecommendConfigurations(Configuration configuration, Set<String> configTypesUpdated) {
    ConfigRecommendationStrategy configRecommendationStrategy = clusterTopology.getConfigRecommendationStrategy();
    Map<String, AdvisedConfiguration> advisedConfigurations = clusterTopology.getAdvisedConfigurations();
    LOG.info("Config recommendation strategy being used is {})", configRecommendationStrategy);

    if (ConfigRecommendationStrategy.ONLY_STACK_DEFAULTS_APPLY.equals(configRecommendationStrategy)) {
      LOG.info("Filter out recommended configurations. Keep only the stack defaults.");
      doFilterStackDefaults(advisedConfigurations);
    }
    if (!ConfigRecommendationStrategy.NEVER_APPLY.equals(configRecommendationStrategy)) {
      for (Map.Entry<String, AdvisedConfiguration> advConfEntry : advisedConfigurations.entrySet()) {
        String configType = advConfEntry.getKey();
        AdvisedConfiguration advisedConfig = advConfEntry.getValue();
        LOG.info("Update '{}' configurations with recommended configurations provided by the stack advisor.", configType);
        if (advisedConfig.getProperties() != null) {
          doReplaceProperties(configuration, configType, advisedConfig, configTypesUpdated);
        }
        if (advisedConfig.getPropertyValueAttributes() != null) {
          doRemovePropertiesIfNeeded(configuration, configType, advisedConfig, configTypesUpdated);
        }
      }
    } else {
      LOG.info("No recommended configurations are applied. (strategy: {})", ConfigRecommendationStrategy.NEVER_APPLY);
    }
  }

  /**
   * Drop every configuration property from advised configuration that is not found in the stack defaults.
   * @param advisedConfigurations advised configuration instance
   */
  private void doFilterStackDefaults(Map<String, AdvisedConfiguration> advisedConfigurations) {
    Blueprint blueprint = clusterTopology.getBlueprint();
    Configuration stackDefaults = blueprint.getStack().getConfiguration(blueprint.getServices());
    Map<String, Map<String, String>> stackDefaultProps = stackDefaults.getProperties();
    for (Map.Entry<String, AdvisedConfiguration> adConfEntry : advisedConfigurations.entrySet()) {
      AdvisedConfiguration advisedConfiguration = adConfEntry.getValue();
      if (stackDefaultProps.containsKey(adConfEntry.getKey())) {
        Map<String, String> defaultProps = stackDefaultProps.get(adConfEntry.getKey());
        if (advisedConfiguration.getProperties() != null) {
          Map<String, String> outFilteredProps = Maps.filterKeys(advisedConfiguration.getProperties(),
            Predicates.not(Predicates.in(defaultProps.keySet())));
          advisedConfiguration.getProperties().keySet().removeAll(Sets.newCopyOnWriteArraySet(outFilteredProps.keySet()));
        }

        if (advisedConfiguration.getPropertyValueAttributes() != null) {
          Map<String, ValueAttributesInfo> outFilteredValueAttrs = Maps.filterKeys(advisedConfiguration.getPropertyValueAttributes(),
            Predicates.not(Predicates.in(defaultProps.keySet())));
          advisedConfiguration.getPropertyValueAttributes().keySet().removeAll(
            Sets.newCopyOnWriteArraySet(outFilteredValueAttrs.keySet()));
        }
      } else {
        advisedConfiguration.getProperties().clear();
      }
    }
  }



  /**
   * Update configuration properties based on advised configuration properties.
   * @param configuration configuration being processed
   * @param configType type of configuration. e.g.: yarn-site
   * @param advisedConfig advised configuration instance
   * @param configTypesUpdated updated config types
   */
  private void doReplaceProperties(Configuration configuration, String configType,
                                   AdvisedConfiguration advisedConfig, Set<String> configTypesUpdated) {
    for (Map.Entry<String, String> propEntry : advisedConfig.getProperties().entrySet()) {
      String originalValue = configuration.getPropertyValue(configType, propEntry.getKey());
      configuration.setProperty(configType, propEntry.getKey(), propEntry.getValue());
      if (!propEntry.getValue().equals(originalValue)) {
        configTypesUpdated.add(configType);
      }
    }
  }

  /**
   * Remove properties that are flagged with 'delete' value attribute.
   * @param configuration configuration being processed
   * @param configType type of configuration. e.g.: yarn-site
   * @param advisedConfig advised configuration instance
   * @param configTypesUpdated updated config types
   */
  private void doRemovePropertiesIfNeeded(Configuration configuration,
                                          String configType, AdvisedConfiguration advisedConfig, Set<String> configTypesUpdated) {
    if (advisedConfig.getPropertyValueAttributes() != null) {
      for (Map.Entry<String, ValueAttributesInfo> valueAttrEntry :
        advisedConfig.getPropertyValueAttributes().entrySet()) {
        if ("true".equalsIgnoreCase(valueAttrEntry.getValue().getDelete())) {
          if(null != configuration.removeProperty(configType, valueAttrEntry.getKey())) {
            configTypesUpdated.add(configType);
          }
        }
      }
    }
  }

  /**
   * Creates a Collection of PropertyUpdater maps that will handle the configuration
   *   update for this cluster.
   *
   *   If NameNode HA is enabled, then updater instances will be added to the
   *   collection, in addition to the default list of Updaters that are statically defined.
   *
   *   Similarly, if Yarn ResourceManager HA is enabled, then updater instances specific
   *   to Yarn HA will be added to the default list of Updaters that are statically defined.
   *
   * @return Collection of PropertyUpdater maps used to handle cluster config update
   */
  Collection<Map<String, Map<String, PropertyUpdater>>> createCollectionOfUpdaters() {
    Collection<Map<String, Map<String, PropertyUpdater>>> updaters = allUpdaters;

    if (clusterTopology.isNameNodeHAEnabled()) {
      updaters = addNameNodeHAUpdaters(updaters);
    }

    if (clusterTopology.isYarnResourceManagerHAEnabled()) {
      updaters = addYarnResourceManagerHAUpdaters(updaters);
    }

    if (isOozieServerHAEnabled(clusterTopology.getConfiguration().getFullProperties())) {
      updaters = addOozieServerHAUpdaters(updaters);
    }

    return updaters;
  }

  /**
   * Creates a Collection of PropertyUpdater maps that include the NameNode HA properties, and
   *   adds these to the list of updaters used to process the cluster configuration.  The HA
   *   properties are based on the names of the HA namservices and name nodes, and so must
   *   be registered at runtime, rather than in the static list.  This new Collection includes
   *   the statically-defined updaters, in addition to the HA-related updaters.
   *
   * @param updaters a Collection of updater maps to be included in the list of updaters for
   *                   this cluster config update
   * @return A Collection of PropertyUpdater maps to handle the cluster config update
   */
  private Collection<Map<String, Map<String, PropertyUpdater>>> addNameNodeHAUpdaters(Collection<Map<String, Map<String, PropertyUpdater>>> updaters) {
    Collection<Map<String, Map<String, PropertyUpdater>>> highAvailabilityUpdaters =
      new LinkedList<>();

    // always add the statically-defined list of updaters to the list to use
    // in processing cluster configuration
    highAvailabilityUpdaters.addAll(updaters);

    // add the updaters for the dynamic HA properties, based on the HA config in hdfs-site
    highAvailabilityUpdaters.add(createMapOfNameNodeHAUpdaters());

    return highAvailabilityUpdaters;
  }

  /**
   * Creates a Collection of PropertyUpdater maps that include the Yarn ResourceManager HA properties, and
   *   adds these to the list of updaters used to process the cluster configuration.  The HA
   *   properties are based on the names of the Resource Manager instances defined in
   *   yarn-site, and so must be registered at runtime, rather than in the static list.
   *
   *   This new Collection includes the statically-defined updaters,
   *   in addition to the HA-related updaters.
   *
   * @param updaters a Collection of updater maps to be included in the list of updaters for
   *                   this cluster config update
   * @return A Collection of PropertyUpdater maps to handle the cluster config update
   */
  private Collection<Map<String, Map<String, PropertyUpdater>>> addYarnResourceManagerHAUpdaters(Collection<Map<String, Map<String, PropertyUpdater>>> updaters) {
    Collection<Map<String, Map<String, PropertyUpdater>>> highAvailabilityUpdaters =
      new LinkedList<>();

    // always add the statically-defined list of updaters to the list to use
    // in processing cluster configuration
    highAvailabilityUpdaters.addAll(updaters);

    // add the updaters for the dynamic HA properties, based on the HA config in hdfs-site
    highAvailabilityUpdaters.add(createMapOfYarnResourceManagerHAUpdaters());

    return highAvailabilityUpdaters;
  }


  /**
   * Creates a Collection of PropertyUpdater maps that include the OozieServer HA properties, and
   *   adds these to the list of updaters used to process the cluster configuration.

   *   This new Collection includes the statically-defined updaters,
   *   in addition to the HA-related updaters.
   *
   * @param updaters a Collection of updater maps to be included in the list of updaters for
   *                   this cluster config update
   * @return A Collection of PropertyUpdater maps to handle the cluster config update
   */
  private Collection<Map<String, Map<String, PropertyUpdater>>> addOozieServerHAUpdaters(Collection<Map<String, Map<String, PropertyUpdater>>> updaters) {
    Collection<Map<String, Map<String, PropertyUpdater>>> highAvailabilityUpdaters =
      new LinkedList<>();

    // always add the statically-defined list of updaters to the list to use
    // in processing cluster configuration
    highAvailabilityUpdaters.addAll(updaters);

    // add the updaters for the Oozie HA properties not defined in stack, but
    // required to be present/updated in oozie-site
    highAvailabilityUpdaters.add(createMapOfOozieServerHAUpdaters());

    return highAvailabilityUpdaters;
  }

  /**
   * Performs export update for the set of properties that do not
   * require update during cluster setup, but should be removed
   * during a Blueprint export.
   *
   * In the case of a service referring to an external DB, any
   * properties that contain external host information should
   * be removed from the configuration that will be available in
   * the exported Blueprint.
   *
   * @param updaters       set of updaters for properties that should
   *                       always be removed during a Blueprint export
   * @param configuration  configuration being processed
   */
  private void doRemovePropertyExport(Map<String, Map<String, PropertyUpdater>> updaters,
                                      Configuration configuration) {

    Map<String, Map<String, String>> properties = configuration.getProperties();
    for (Map.Entry<String, Map<String, PropertyUpdater>> entry : updaters.entrySet()) {
      String type = entry.getKey();
      for (String propertyName : entry.getValue().keySet()) {
        Map<String, String> typeProperties = properties.get(type);
        if ( (typeProperties != null) && (typeProperties.containsKey(propertyName)) ) {
          configuration.removeProperty(type, propertyName);
        }
      }
    }
  }

  /**
   * Perform export update processing for HA configuration for NameNodes.  The HA NameNode property
   *   names are based on the nameservices defined when HA is enabled via the Ambari UI, so this method
   *   dynamically determines the property names, and registers PropertyUpdaters to handle the masking of
   *   host names in these configuration items.
   *
   */
  public void doNameNodeHAUpdate() {
    Map<String, Map<String, PropertyUpdater>> highAvailabilityUpdaters = createMapOfNameNodeHAUpdaters();

    // perform a single host update on these dynamically generated property names
    if (highAvailabilityUpdaters.get("hdfs-site").size() > 0) {
      doSingleHostExportUpdate(highAvailabilityUpdaters, clusterTopology.getConfiguration());
    }
  }

  /**
   * Perform export update processing for HA configuration for Yarn ResourceManagers.  The HA ResourceManager
   * property names are based on the ResourceManager names defined when HA is enabled via the Ambari UI, so this method
   * dynamically determines the property names, and registers PropertyUpdaters to handle the masking of
   * host names in these configuration items.
   *
   */
  public void doYarnResourceManagerHAUpdate() {
    Map<String, Map<String, PropertyUpdater>> highAvailabilityUpdaters = createMapOfYarnResourceManagerHAUpdaters();

    // perform a single host update on these dynamically generated property names
    if (highAvailabilityUpdaters.get("yarn-site").size() > 0) {
      doSingleHostExportUpdate(highAvailabilityUpdaters, clusterTopology.getConfiguration());
    }
  }

  /**
   * Perform export update processing for HA configuration for Oozie servers.  The properties used
   * in Oozie HA are not defined in the stack, but need to be added at runtime during an HA
   * deployment in order to support exporting/redeploying clusters with Oozie HA config.
   *
   */
  public void doOozieServerHAUpdate() {
    Map<String, Map<String, PropertyUpdater>> highAvailabilityUpdaters = createMapOfOozieServerHAUpdaters();

    if (highAvailabilityUpdaters.get("oozie-site").size() > 0) {
      doMultiHostExportUpdate(highAvailabilityUpdaters, clusterTopology.getConfiguration());
    }
  }


  /**
   * Creates map of PropertyUpdater instances that are associated with
   *   NameNode High Availability (HA).  The HA configuration property
   *   names are dynamic, and based on other HA config elements in
   *   hdfs-site.  This method registers updaters for the required
   *   properties associated with each nameservice and namenode.
   *
   * @return a Map of registered PropertyUpdaters for handling HA properties in hdfs-site
   */
  private Map<String, Map<String, PropertyUpdater>> createMapOfNameNodeHAUpdaters() {
    Map<String, Map<String, PropertyUpdater>> highAvailabilityUpdaters = new HashMap<>();
    Map<String, PropertyUpdater> hdfsSiteUpdatersForAvailability = new HashMap<>();
    highAvailabilityUpdaters.put("hdfs-site", hdfsSiteUpdatersForAvailability);

    //todo: Do we need to call this for HG configurations?
    Map<String, String> hdfsSiteConfig = clusterTopology.getConfiguration().getFullProperties().get("hdfs-site");
    // generate the property names based on the current HA config for the NameNode deployments
    for (String nameService : parseNameServices(hdfsSiteConfig)) {
      final String journalEditsDirPropertyName = "dfs.namenode.shared.edits.dir." + nameService;
      // register an updater for the nameservice-specific shared edits dir
      hdfsSiteUpdatersForAvailability.put(journalEditsDirPropertyName, new MultipleHostTopologyUpdater("JOURNALNODE", ';', false, false, true));

      for (String nameNode : parseNameNodes(nameService, hdfsSiteConfig)) {
        final String httpsPropertyName = "dfs.namenode.https-address." + nameService + "." + nameNode;
        hdfsSiteUpdatersForAvailability.put(httpsPropertyName, new SingleHostTopologyUpdater("NAMENODE"));
        final String httpPropertyName = "dfs.namenode.http-address." + nameService + "." + nameNode;
        hdfsSiteUpdatersForAvailability.put(httpPropertyName, new SingleHostTopologyUpdater("NAMENODE"));
        final String rpcPropertyName = "dfs.namenode.rpc-address." + nameService + "." + nameNode;
        hdfsSiteUpdatersForAvailability.put(rpcPropertyName, new SingleHostTopologyUpdater("NAMENODE"));
        final String serviceRpcPropertyName = "dfs.namenode.servicerpc-address." + nameService + "." + nameNode;
        hdfsSiteUpdatersForAvailability.put(serviceRpcPropertyName, new SingleHostTopologyUpdater("NAMENODE"));
      }
    }
    return highAvailabilityUpdaters;
  }


  /**
   * Creates map of PropertyUpdater instances that are associated with
   *   Yarn ResourceManager High Availability (HA).  The HA configuration property
   *   names are dynamic, and based on other HA config elements in
   *   yarn-site.  This method registers updaters for the required
   *   properties associated with each ResourceManager.
   *
   * @return a Map of registered PropertyUpdaters for handling HA properties in yarn-site
   */
  private Map<String, Map<String, PropertyUpdater>> createMapOfYarnResourceManagerHAUpdaters() {
    Map<String, Map<String, PropertyUpdater>> highAvailabilityUpdaters = new HashMap<>();
    Map<String, PropertyUpdater> yarnSiteUpdatersForAvailability = new HashMap<>();
    highAvailabilityUpdaters.put("yarn-site", yarnSiteUpdatersForAvailability);

    Map<String, String> yarnSiteConfig = clusterTopology.getConfiguration().getFullProperties().get("yarn-site");
    // generate the property names based on the current HA config for the ResourceManager deployments
    for (String resourceManager : parseResourceManagers(yarnSiteConfig)) {
      SingleHostTopologyUpdater updater = new SingleHostTopologyUpdater("RESOURCEMANAGER");
      yarnSiteUpdatersForAvailability.put("yarn.resourcemanager.hostname." + resourceManager, updater);
      yarnSiteUpdatersForAvailability.put("yarn.resourcemanager.address." + resourceManager, updater);
      yarnSiteUpdatersForAvailability.put("yarn.resourcemanager.admin.address." + resourceManager, updater);
      yarnSiteUpdatersForAvailability.put("yarn.resourcemanager.resource-tracker.address." + resourceManager, updater);
      yarnSiteUpdatersForAvailability.put("yarn.resourcemanager.scheduler.address." + resourceManager, updater);
      yarnSiteUpdatersForAvailability.put("yarn.resourcemanager.webapp.address." + resourceManager, updater);
      yarnSiteUpdatersForAvailability.put("yarn.resourcemanager.webapp.https.address." + resourceManager, updater);
    }

    return highAvailabilityUpdaters;
  }

  /**
   * Creates map of PropertyUpdater instances that are associated with
   *   Oozie Server High Availability (HA).
   *
   * @return a Map of registered PropertyUpdaters for handling HA properties in oozie-site
   */
  private Map<String, Map<String, PropertyUpdater>> createMapOfOozieServerHAUpdaters() {
    Map<String, Map<String, PropertyUpdater>> highAvailabilityUpdaters = new HashMap<>();
    Map<String, PropertyUpdater> oozieSiteUpdatersForAvailability = new HashMap<>();
    highAvailabilityUpdaters.put("oozie-site", oozieSiteUpdatersForAvailability);

    // register a multi-host property updater for this Oozie property.
    // this property is not defined in the stacks, since HA is not supported yet
    // by the stack definition syntax.  This property should only be considered in
    // an Oozie HA cluster.
    oozieSiteUpdatersForAvailability.put("oozie.zookeeper.connection.string", new MultipleHostTopologyUpdater("ZOOKEEPER_SERVER"));

    return highAvailabilityUpdaters;

  }

  /**
   * Static convenience function to determine if Oozie HA is enabled
   * @param configProperties configuration properties for this cluster
   * @return true if Oozie HA is enabled
   *         false if Oozie HA is not enabled
   */
  //todo: pass in configuration
  static boolean isOozieServerHAEnabled(Map<String, Map<String, String>> configProperties) {
    return configProperties.containsKey("oozie-site") && configProperties.get("oozie-site").containsKey("oozie.services.ext")
      && configProperties.get("oozie-site").get("oozie.services.ext").contains("org.apache.oozie.service.ZKLocksService");
  }

  /**
   * Static convenience function to determine if HiveServer HA is enabled
   * @param configProperties configuration properties for this cluster
   * @return true if HiveServer HA is enabled
   *         false if HiveServer HA is not enabled
   */
  static boolean isHiveServerHAEnabled(Map<String, Map<String, String>> configProperties) {
    return configProperties.containsKey("hive-site") && configProperties.get("hive-site").containsKey("hive.server2.support.dynamic.service.discovery")
      && configProperties.get("hive-site").get("hive.server2.support.dynamic.service.discovery").equals("true");
  }

  /**
   * Convenience method to examine the current configuration, to determine
   * if the hostname of the initial active namenode in an HA deployment has
   * been included.
   *
   * @param configProperties the configuration for this cluster
   * @return true if the initial active namenode property has been configured
   *         false if the initial active namenode property has not been configured
   */
  static boolean isNameNodeHAInitialActiveNodeSet(Map<String, Map<String, String>> configProperties) {
    return configProperties.containsKey(HDFS_HA_INITIAL_CONFIG_TYPE) && configProperties.get(HDFS_HA_INITIAL_CONFIG_TYPE).containsKey(HDFS_ACTIVE_NAMENODE_PROPERTY_NAME);
  }


  /**
   * Convenience method to examine the current configuration, to determine
   * if the hostname of the initial standby namenode in an HA deployment has
   * been included.
   *
   * @param configProperties the configuration for this cluster
   * @return true if the initial standby namenode property has been configured
   *         false if the initial standby namenode property has not been configured
   */
  static boolean isNameNodeHAInitialStandbyNodeSet(Map<String, Map<String, String>> configProperties) {
    return configProperties.containsKey(HDFS_HA_INITIAL_CONFIG_TYPE) && configProperties.get(HDFS_HA_INITIAL_CONFIG_TYPE).containsKey(HDFS_STANDBY_NAMENODE_PROPERTY_NAME);
  }

  /**
   * General convenience method to determine if a given property has been set in the cluster configuration
   *
   * @param configProperties the configuration for this cluster
   * @param configType the config type to check
   * @param propertyName the property name to check
   * @return true if the named property has been set
   *         false if the named property has not been set
   */
  static boolean isPropertySet(Map<String, Map<String, String>> configProperties, String configType, String propertyName) {
    return configProperties.containsKey(configType) && configProperties.get(configType).containsKey(propertyName);
  }


  /**
   * Parses out the list of nameservices associated with this HDFS configuration.
   *
   * @param properties config properties for this cluster
   *
   * @return array of Strings that indicate the nameservices for this cluster
   */
  static String[] parseNameServices(Map<String, String> properties) {
    String nameServices = properties.get("dfs.internal.nameservices");
    if (nameServices == null) {
      nameServices = properties.get("dfs.nameservices");
    }
    return splitAndTrimStrings(nameServices);
  }

  /**
   * Parses out the list of resource managers associated with this yarn-site configuration.
   *
   * @param properties config properties for this cluster
   *
   * @return array of Strings that indicate the ResourceManager names for this HA cluster
   */
  static String[] parseResourceManagers(Map<String, String> properties) {
    final String resourceManagerNames = properties.get("yarn.resourcemanager.ha.rm-ids");
    return splitAndTrimStrings(resourceManagerNames);
  }

  /**
   * Parses out the list of name nodes associated with a given HDFS
   *   NameService, based on a given HDFS configuration.
   *
   * @param nameService the nameservice used for this parsing
   * @param properties config properties for this cluster
   *
   * @return array of Strings that indicate the name nodes associated
   *           with this nameservice
   */
  static String[] parseNameNodes(String nameService, Map<String, String> properties) {
    final String nameNodes = properties.get("dfs.ha.namenodes." + nameService);
    return splitAndTrimStrings(nameNodes);
  }

  /**
   * Iterates over the list of registered filters for this config processor, and
   * queries each filter to determine if a given property should be included
   * in a property collection.  If any filters return false for the isPropertyIncluded()
   * query, then the property should be excluded.
   *
   * @param propertyName config property name
   * @param propertyValue config property value
   * @param propertyType config type that contains this property
   * @param topology cluster topology instance
   * @return true if the property should be excluded
   *         false if the property should not be excluded
   */
  private boolean shouldPropertyBeExcludedForBlueprintExport(String propertyName, String propertyValue, String propertyType, ClusterTopology topology, PropertyFilter [] exportPropertyFilters ) {
    for(PropertyFilter filter : exportPropertyFilters) {
      if (!filter.isPropertyIncluded(propertyName, propertyValue, propertyType, topology)) {
        return true;
      }
    }

    // if no filters require that the property be excluded,
    // then allow it to be included in the property collection
    return false;
  }

  /**
   * Convenience method to iterate over the cluster update filters, and determine if a given property
   * should be excluded from a collection.
   *
   * @param propertyName name of property to examine
   * @param propertyValue value of the current property
   * @param propertyType configuration type that contains this property
   * @param topology the cluster topology instance
   * @return true if the given property should be excluded
   *         false if the given property should be included
   */
  private static boolean shouldPropertyBeExcludedForClusterUpdate(String propertyName,
                                                                  String propertyValue,
                                                                  String propertyType,
                                                                  ClusterTopology topology) {

    for(PropertyFilter filter : clusterUpdatePropertyFilters) {
      try {
        if (!filter.isPropertyIncluded(propertyName, propertyValue, propertyType, topology)) {
          if (!shouldPropertyBeStoredWithDefault(propertyName)) {
            return true;
          }
        }
      } catch (Throwable throwable) {
        // if any error occurs during a filter execution, just log it
        LOG.warn("Error occurred while attempting to process the property '" + propertyName + "' with a filter.  This may indicate a config error.", throwable);
      }
    }

    // if no filters require that the property be excluded,
    // then allow it to be included in the property collection
    return false;
  }

  /**
   * Update single host topology configuration properties for blueprint export.
   *
   * @param updaters       registered updaters
   * @param configuration  configuration being processed
   */
  private void doSingleHostExportUpdate(Map<String, Map<String, PropertyUpdater>> updaters, Configuration configuration) {
    Map<String, Map<String, String>> properties = configuration.getFullProperties();
    for (Map.Entry<String, Map<String, PropertyUpdater>> entry : updaters.entrySet()) {
      String type = entry.getKey();
      for (String propertyName : entry.getValue().keySet()) {
        boolean matchedHost = false;

        Map<String, String> typeProperties = properties.get(type);
        if (typeProperties != null && typeProperties.containsKey(propertyName)) {
          String propValue = typeProperties.get(propertyName);

          for (HostGroupInfo groupInfo : clusterTopology.getHostGroupInfo().values()) {
            Collection<String> hosts = groupInfo.getHostNames();
            for (String host : hosts) {
              //todo: need to use regular expression to avoid matching a host which is a superset.
              if (propValue.contains(host)) {
                matchedHost = true;
                configuration.setProperty(type, propertyName,
                  propValue.replace(host, "%HOSTGROUP::" + groupInfo.getHostGroupName() + "%"));
                break;
              }
            }
            if (matchedHost) {
              break;
            }
          }
          // remove properties that do not contain hostnames,
          // except in the case of HA-related properties, that
          // can contain nameservice references instead of hostnames (Fix for Bug AMBARI-7458).
          // also will not remove properties that reference the special 0.0.0.0 network
          // address or properties with undefined hosts
          if (! matchedHost &&
            ! isNameServiceProperty(propertyName) &&
            ! isSpecialNetworkAddress(propValue)  &&
            ! isUndefinedAddress(propValue) &&
            ! isPlaceholder(propValue)) {

            configuration.removeProperty(type, propertyName);
          }
        }
      }
    }
  }

  /**
   * Determine if a property is a placeholder
   *
   * @param propertyValue  property value
   *
   * @return true if the property has format "{{%s}}"
   */
  private static boolean isPlaceholder(String propertyValue) {
    return PLACEHOLDER.matcher(propertyValue).find();
  }

  /**
   * Determines if a given property name's value can include
   *   nameservice references instead of host names.
   *
   * @param propertyName name of the property
   *
   * @return true if this property can support using nameservice names
   *         false if this property cannot support using nameservice names
   */
  private static boolean isNameServiceProperty(String propertyName) {
    return configPropertiesWithHASupport.contains(propertyName);
  }

  /**
   * Queries a property value to determine if the value contains
   *   a host address with all zeros (0.0.0.0).  This is a special
   *   address that signifies that the service is available on
   *   all network interfaces on a given machine.
   *
   * @param propertyValue the property value to inspect
   *
   * @return true if the 0.0.0.0 address is included in this string
   *         false if the 0.0.0.0 address is not included in this string
   */
  private static boolean isSpecialNetworkAddress(String propertyValue) {
    return propertyValue.contains(BIND_ALL_IP_ADDRESS);
  }

  /**
   * Determine if a property has an undefined host.
   *
   * @param propertyValue  property value
   *
   * @return true if the property value contains "undefined"
   */
  private static boolean isUndefinedAddress(String propertyValue) {
    return propertyValue.contains("undefined");
  }

  /**
   * Update multi host topology configuration properties for blueprint export.
   *
   * @param updaters       registered updaters
   * @param configuration  configuration being processed
   */
  private void doMultiHostExportUpdate(Map<String, Map<String, PropertyUpdater>> updaters, Configuration configuration) {
    Map<String, Map<String, String>> properties = configuration.getFullProperties();
    for (Map.Entry<String, Map<String, PropertyUpdater>> entry : updaters.entrySet()) {
      String type = entry.getKey();
      for (String propertyName : entry.getValue().keySet()) {
        Map<String, String> typeProperties = properties.get(type);
        if (typeProperties != null && typeProperties.containsKey(propertyName)) {
          String propValue = typeProperties.get(propertyName);
          for (HostGroupInfo groupInfo : clusterTopology.getHostGroupInfo().values()) {
            Collection<String> hosts = groupInfo.getHostNames();
            for (String host : hosts) {
              propValue = propValue.replaceAll(host + "\\b", "%HOSTGROUP::" +
                groupInfo.getHostGroupName() + "%");
            }
          }
          Collection<String> addedGroups = new HashSet<>();
          String[] toks = propValue.split(",");
          boolean inBrackets = propValue.startsWith("[");

          StringBuilder sb = new StringBuilder();
          if (inBrackets) {
            sb.append('[');
          }
          boolean firstTok = true;
          for (String tok : toks) {
            tok = tok.replaceAll("[\\[\\]]", "");

            if (addedGroups.add(tok)) {
              if (! firstTok) {
                sb.append(',');
              }
              sb.append(tok);
            }
            firstTok = false;
          }

          if (inBrackets) {
            sb.append(']');
          }
          configuration.setProperty(type, propertyName, sb.toString());
        }
      }
    }
  }

  /**
   * Convert a property value which includes a host group topology token to a physical host.
   *
   *
   * @param val       value to be converted
   * @param topology  cluster topology
   *
   * @return updated value with physical host name
   */
  //todo: replace this with parseHostGroupToken which would return a hostgroup or null
  private static Collection<String> getHostStrings(String val, ClusterTopology topology) {

    Collection<String> hosts = new LinkedHashSet<>();
    Matcher m = HOSTGROUP_PORT_REGEX.matcher(val);
    while (m.find()) {
      String groupName = m.group(1);
      String port = m.group(2);

      HostGroupInfo hostGroupInfo = topology.getHostGroupInfo().get(groupName);
      if (hostGroupInfo == null) {
        throw new IllegalArgumentException(
          "Unable to match blueprint host group token to a host group: " + groupName);
      }

      for (String host : hostGroupInfo.getHostNames()) {
        if (port != null) {
          host += ":" + port;
        }
        hosts.add(host);
      }
    }
    return hosts;
  }

  /**
   * Convenience method for splitting out the HA-related properties, while
   *   also removing leading/trailing whitespace.
   *
   * @param propertyName property name to parse
   *
   * @return an array of Strings that represent the comma-separated
   *         elements in this property
   */
  private static String[] splitAndTrimStrings(String propertyName) {
    if(propertyName != null) {
      List<String> namesWithoutWhitespace = new LinkedList<>();
      for (String service : propertyName.split(",")) {
        namesWithoutWhitespace.add(service.trim());
      }

      return namesWithoutWhitespace.toArray(new String[namesWithoutWhitespace.size()]);
    } else {
      return new String[0];
    }
  }

  /**
   * Update non topology related configuration properties for blueprint export.
   *
   * @param updaters       registered non topology updaters
   * @param configuration  configuration being processed
   */
  private void doNonTopologyUpdate(Map<String, Map<String, PropertyUpdater>> updaters, Configuration configuration) {
    Map<String, Map<String, String>> properties = configuration.getFullProperties();
    for (Map.Entry<String, Map<String, PropertyUpdater>> entry : updaters.entrySet()) {
      String type = entry.getKey();
      for (String propertyName : entry.getValue().keySet()) {
        PropertyUpdater pu = entry.getValue().get(propertyName);
        Map<String, String> typeProperties = properties.get(type);

        if (typeProperties != null && typeProperties.containsKey(propertyName)) {
          String newValue = pu.updateForBlueprintExport(propertyName, typeProperties.get(propertyName), properties, clusterTopology);
          configuration.setProperty(type, propertyName, newValue);
        }
      }
    }
  }

  /**
   * Provides functionality to update a property value.
   */
  public interface PropertyUpdater {
    /**
     * Update a property value.
     *
     * @param propertyName    property name
     * @param origValue       original value of property
     * @param properties      all properties
     * @param topology        cluster topology
     *
     * @return new property value
     */
    String updateForClusterCreate(String propertyName,
                                  String origValue,
                                  Map<String, Map<String, String>> properties,
                                  ClusterTopology topology);

    default String updateForBlueprintExport(String propertyName, String value, Map<String, Map<String, String>> properties, ClusterTopology topology) {
      return value;
    }

    /**
     * Determine the required host groups for the provided property.
     *
     * @param propertyName    property name
     * @param origValue       original value of property
     * @param properties      all properties
     * @param topology        cluster topology
     *
     * @return new property value
     */
    Collection<String> getRequiredHostGroups(String propertyName,
                                             String origValue,
                                             Map<String, Map<String, String>> properties,
                                             ClusterTopology topology);

    /**
     * @return the default updater to apply on user defined (blueprint + cluster template, not stack defaults) properties
     * configuration properties that do not have a registered updater
     */
    static PropertyUpdater defaultUpdater() {
      return HostGroupUpdater.INSTANCE;
    }
  }

  static class HostGroupUpdater implements PropertyUpdater {

    static final HostGroupUpdater INSTANCE = new HostGroupUpdater();

    @Override
    public String updateForClusterCreate(String propertyName,
                                         String origValue,
                                         Map<String, Map<String, String>> properties,
                                         ClusterTopology topology) {

      if (origValue == null) {
        LOG.info("Property {} is null, skipping search for host group placeholder", propertyName);
        return null;
      }

      HostGroups hostGroups = new HostGroups(topology, propertyName);

      //todo: getHostStrings (?)

      // replaces all %HOSTGROUP::name% references to host names in the value string one by one. The value string can contain
      // only one (typical) or multiple %HOSTGROUP references. If the same host group is referenced multiple times,
      // another host will be picked each time.
      // Assuming you have the following hostgroups and hosts:
      // - hostgroup1: [group1_host]
      // - hostgroup2: [group2_host]
      // - hostgroup3: [group3_host1, group3_host2, group3_host3]
      // the following replacements will be made:
      // - %HOSTGROUP::group1%:8080 --> grop1_host:8080
      // - %HOSTGROUP::group1%:8080,%HOSTGROUP::group2%:8080 --> group1_host:8080,group2_host:8080
      // - %HOSTGROUP::group3%:8080,%HOSTGROUP::group3%:8080,%HOSTGROUP::group3%:8080 -->
      //      group3_host1:8080,group3_host2:8080,group3_host3:8080 (maybe in different order)
      LinkedList<Pair<Pair<Integer, Integer>, String>> replacements = new LinkedList<>();
      for (Matcher m = HostGroup.HOSTGROUP_REGEX.matcher(origValue); m.find(); ) {
        String replacement = hostGroups.getHost(m.group(1));
        int from = m.start();
        int to = m.end();
        replacements.add(Pair.of(Pair.of(from, to), replacement));
      }
      StringBuilder newValue = new StringBuilder(origValue);
      // replace in descending order so indices remain valid
      for (Iterator<Pair<Pair<Integer, Integer>, String>> it = replacements.descendingIterator(); it.hasNext(); ) {
        Pair<Pair<Integer, Integer>, String> replacement = it.next();
        int from = replacement.getLeft().getLeft();
        int to = replacement.getLeft().getRight();
        String replacementValue = replacement.getRight();
        newValue.replace(from, to, replacementValue);
      }
      return newValue.toString();
    }

    @Override
    public Collection<String> getRequiredHostGroups(String propertyName,
                                                    String origValue,
                                                    Map<String, Map<String, String>> properties,
                                                    ClusterTopology topology) {
      if (origValue == null) {
        LOG.info("Property {} is null, skipping search for host group placeholder", propertyName);
        return Collections.emptyList();
      }

      //todo: getHostStrings
      Matcher m = HostGroup.HOSTGROUP_REGEX.matcher(origValue);
      Set<String> hostGroups = new HashSet<>();
      while (m.find()) {
        hostGroups.add(m.group(1));
      }
      return hostGroups;
    }

    static class HostGroups {
      private ClusterTopology topology;
      private String propertyName; // for logging purpose only
      private Set<String> hostGroupsUsed = new HashSet<>();

      HostGroups(ClusterTopology topology, String propertyName) {
        this.topology = topology;
        this.propertyName = propertyName;
      }

      String getHost(String hostGroup) {
        Preconditions.checkState(!hostGroupsUsed.contains(hostGroup),
          "Multiple occurrence of host group [%s] in property value of: [%s].", hostGroup, propertyName);
        HostGroupInfo hostGroupInfo = topology.getHostGroupInfo().get(hostGroup);
        Preconditions.checkArgument(null != hostGroupInfo,
          "Encountered a host group token in configuration which couldn't be matched to a host group: %s", hostGroup);
        if (hostGroupInfo.getHostNames().size() > 1) {
          LOG.warn("Host group {} contains multiple hosts. Using {} with such host groups may result in unintended configuration.",
            hostGroup, HostGroupUpdater.class.getSimpleName());
        }
        hostGroupsUsed.add(hostGroup);
        return hostGroupInfo.getHostNames().iterator().next();
      }
    }
  }

  /**
   * Topology based updater which replaces the original host name of a property with the host name
   * which runs the associated (master) component in the new cluster.
   */
  private static class SingleHostTopologyUpdater extends HostGroupUpdater {
    /**
     * Component name
     */
    private final String component;

    /**
     * Constructor.
     *
     * @param component  component name associated with the property
     */
    public SingleHostTopologyUpdater(String component) {
      this.component = component;
    }

    /**
     * Update the property with the new host name which runs the associated component.
     *
     * @param propertyName name of property
     * @param origValue    original value of property
     * @param properties   all properties
     * @param topology     cluster topology
     * @return updated property value with old host name replaced by new host name
     */
    @Override
    public String updateForClusterCreate(String propertyName,
                                         String origValue,
                                         Map<String, Map<String, String>> properties,
                                         ClusterTopology topology) {

      String replacedValue = super.updateForClusterCreate(propertyName, origValue, properties, topology);
      // %HOSTGROUP% token replacement happened
      if (!Objects.equals(origValue, replacedValue)) {
        return replacedValue;
      }
      // localhost typically means stack default values. If property is set to a concrete value such as an FQDN skip
      // validation and update
      else if (null != origValue && !origValue.contains(LOCALHOST)) {
        return origValue;
      }
      else {
        int matchingGroupCount = topology.getHostGroupsForComponent(component).size();
        if (matchingGroupCount == 1) {
          //todo: warn if > 1 hosts
          return origValue.replace(LOCALHOST, topology.getHostAssignmentsForComponent(component).iterator().next() );
        } else {
          //todo: extract all hard coded HA logic
          Cardinality cardinality = topology.getBlueprint().getStack().getCardinality(component);
          // if no matching host groups are found for a component whose configuration
          // is handled by this updater, check the stack first to determine if
          // zero is a valid cardinality for this component.  This is necessary
          // in the case of a component in "technical preview" status, since it
          // may be valid to have 0 or 1 instances of such a component in the cluster
          if (matchingGroupCount == 0 && cardinality.isValidCount(0)) {
            return origValue;
          } else {
            if (topology.isNameNodeHAEnabled() && isComponentNameNode() && (matchingGroupCount >= 2)) {
              // if this is the defaultFS property, it should reflect the nameservice name,
              // rather than a hostname (used in non-HA scenarios)
              if (properties.containsKey("core-site") && properties.get("core-site").get("fs.defaultFS").equals(origValue)) {
                return origValue;
              }

              if (properties.containsKey("hbase-site") && properties.get("hbase-site").get("hbase.rootdir").equals(origValue)) {
                // hbase-site's reference to the namenode is handled differently in HA mode, since the
                // reference must point to the logical nameservice, rather than an individual namenode
                return origValue;
              }

              if (properties.containsKey("accumulo-site") && properties.get("accumulo-site").get("instance.volumes").equals(origValue)) {
                // accumulo-site's reference to the namenode is handled differently in HA mode, since the
                // reference must point to the logical nameservice, rather than an individual namenode
                return origValue;
              }
            }

            if (topology.isNameNodeHAEnabled() && isComponentSecondaryNameNode() && (matchingGroupCount == 0)) {
              // if HDFS HA is enabled, then no replacement is necessary for properties that refer to the SECONDARY_NAMENODE
              // eventually this type of information should be encoded in the stacks
              return origValue;
            }

            if (topology.isComponentHadoopCompatible(component)) {
              return origValue;
            }

            throw new IllegalArgumentException(
              String.format("Unable to update configuration property '%s' with topology information. " +
                "Component '%s' is mapped to an invalid number of host groups '%s'.", propertyName, component, matchingGroupCount));
          }
        }
      }
    }

    @Override
    public Collection<String> getRequiredHostGroups(String propertyName,
                                                    String origValue,
                                                    Map<String, Map<String, String>> properties,
                                                    ClusterTopology topology) {
      Collection<String> result = super.getRequiredHostGroups(propertyName, origValue, properties, topology);
      if (!result.isEmpty()) {
        return result;
      } else {
        Collection<String> matchingGroups = topology.getHostGroupsForComponent(component);
        int matchingGroupCount = matchingGroups.size();
        if (matchingGroupCount != 0) {
          return new HashSet<>(matchingGroups);
        } else {
          Cardinality cardinality = topology.getBlueprint().getStack().getCardinality(component);
          // if no matching host groups are found for a component whose configuration
          // is handled by this updater, return an empty set
          if (! cardinality.isValidCount(0)) {
            LOG.warn("The property '{}' is associated with the component '{}' which isn't mapped to any host group. " +
              "This may affect configuration topology resolution.", propertyName, component);
          }
          return Collections.emptySet();
        }
      }
    }

    /**
     * Utility method to determine if the component associated with this updater
     * instance is an HDFS NameNode
     *
     * @return true if the component associated is a NameNode
     *         false if the component is not a NameNode
     */
    private boolean isComponentNameNode() {
      return component.equals("NAMENODE");
    }


    /**
     * Utility method to determine if the component associated with this updater
     * instance is an HDFS Secondary NameNode
     *
     * @return true if the component associated is a Secondary NameNode
     *         false if the component is not a Secondary NameNode
     */
    private boolean isComponentSecondaryNameNode() {
      return component.equals("SECONDARY_NAMENODE");
    }

    /**
     * Utility method to determine if the component associated with this updater
     * instance is a Yarn ResourceManager
     *
     * @return true if the component associated is a Yarn ResourceManager
     *         false if the component is not a Yarn ResourceManager
     */
    private boolean isComponentResourceManager() {
      return component.equals("RESOURCEMANAGER");
    }

    /**
     * Utility method to determine if the component associated with this updater
     * instance is an Oozie Server
     *
     * @return true if the component associated is an Oozie Server
     *         false if the component is not an Oozie Server
     */
    private boolean isComponentOozieServer() {
      return component.equals("OOZIE_SERVER");
    }

    /**
     * Utility method to determine if the component associated with this updater
     * instance is a Hive Server
     *
     * @return true if the component associated is a Hive Server
     *         false if the component is not a Hive Server
     */
    private boolean isComponentHiveServer() {
      return component.equals("HIVE_SERVER");
    }

    /**
     * Utility method to determine if the component associated with this updater
     * instance is a Hive MetaStore Server
     *
     * @return true if the component associated is a Hive MetaStore Server
     *         false if the component is not a Hive MetaStore Server
     */
    private boolean isComponentHiveMetaStoreServer() {
      return component.equals("HIVE_METASTORE");
    }

    /**
     * Utility method to determine if the component associated with this updater
     * instance is Ranger Admin
     *
     * @return true if the component associated is Ranger Admin
     *         false if the component is not Ranger Admin
     */
    private boolean isRangerAdmin() {
      return component.equals("RANGER_ADMIN");
    }


    /**
     * Utility method to determine if the component associated with this updater
     * instance is a History Server
     *
     * @return true if the component associated is a History Server
     *         false if the component is not a History Server
     */
    private boolean isComponentHistoryServer() {
      return component.equals("HISTORYSERVER");
    }


    /**
     * Utility method to determine if the component associated with this updater
     * instance is a AppTimeline Server
     *
     * @return true if the component associated is a AppTimeline Server
     *         false if the component is not a AppTimeline Server
     */
    private boolean isComponentAppTimelineServer() {
      return component.equals("APP_TIMELINE_SERVER");
    }


    /**
     * Provides access to the name of the component associated
     *   with this updater instance.
     *
     * @return component name for this updater
     */
    public String getComponentName() {
      return component;
    }

  }

  /**
   * Extension of SingleHostTopologyUpdater that supports the
   * notion of an optional service.  An example: the Storm
   * service has config properties that require the location
   * of the Ganglia server when Ganglia is deployed, but Storm
   * should also start properly without Ganglia.
   *
   * This updater detects the case when the specified component
   * is not found, and returns the original property value.
   *
   * @deprecated {@link SingleHostTopologyUpdater} has been changed not to validate explicitly set (other than
   *   the typically stack default {@code localhost}) values. The new semantics make this class obsolete. If you want to
   *   submit a cluster with some intentionally missing components, set respective properties to a value other than the
   *   stack default {@code localhost} (e.g it can be empty string or and FQDN).
   */
  @Deprecated
  private static class OptionalSingleHostTopologyUpdater extends SingleHostTopologyUpdater {

    public OptionalSingleHostTopologyUpdater(String component) {
      super(component);
    }

    @Override
    public String updateForClusterCreate(String propertyName,
                                         String origValue,
                                         Map<String, Map<String, String>> properties,
                                         ClusterTopology topology) {
      try {
        return super.updateForClusterCreate(propertyName, origValue, properties, topology);
      } catch (IllegalArgumentException illegalArgumentException) {
        LOG.warn("Error while updating property [{}] with original value [{}]. Exception message: {}",
          propertyName, origValue, illegalArgumentException.getMessage());
        // return the original value, since the optional component is not available in this cluster
        return origValue;
      }
    }

    @Override
    public Collection<String> getRequiredHostGroups(String propertyName,
                                                    String origValue,
                                                    Map<String, Map<String, String>> properties,
                                                    ClusterTopology topology) {

      try {
        return super.getRequiredHostGroups(propertyName, origValue, properties, topology);
      } catch (IllegalArgumentException e) {
        return Collections.emptySet();
      }
    }
  }

  /**
   * Topology based updater which replaces the original host name of a database property with the host name
   * where the DB is deployed in the new cluster.  If an existing database is specified, the original property
   * value is returned.
   */
  private static class DBTopologyUpdater extends SingleHostTopologyUpdater {
    /**
     * Property type (global, core-site ...) for property which is used to determine if DB is external.
     */
    private final String configPropertyType;

    /**
     * Name of property which is used to determine if DB is new or existing (exernal).
     */
    private final String conditionalPropertyName;

    /**
     * Constructor.
     *
     * @param component                component to get hot name if new DB
     * @param conditionalPropertyType  config type of property used to determine if DB is external
     * @param conditionalPropertyName  name of property which is used to determine if DB is external
     */
    private DBTopologyUpdater(String component, String conditionalPropertyType,
                              String conditionalPropertyName) {
      super(component);
      configPropertyType = conditionalPropertyType;
      this.conditionalPropertyName = conditionalPropertyName;
    }

    /**
     * If database is a new managed database, update the property with the new host name which
     * runs the associated component.  If the database is external (non-managed), return the
     * original value.
     *
     * @param propertyName  property name
     * @param origValue     original value of property
     * @param properties    all properties
     * @param topology      cluster topology
     *
     * @return updated property value with old host name replaced by new host name or original value
     *         if the database is external
     */
    @Override

    public String updateForClusterCreate(String propertyName,
                                         String origValue,
                                         Map<String, Map<String, String>> properties,
                                         ClusterTopology topology) {

      if (isDatabaseManaged(properties)) {
        return super.updateForClusterCreate(propertyName, origValue, properties, topology);
      } else {
        return origValue;
      }
    }

    @Override
    public Collection<String> getRequiredHostGroups(String propertyName,
                                                    String origValue,
                                                    Map<String, Map<String, String>> properties,
                                                    ClusterTopology topology) {
      if (isDatabaseManaged(properties)) {
        return super.getRequiredHostGroups(propertyName, origValue, properties, topology);
      } else {
        return Collections.emptySet();
      }
    }

    /**
     * Determine if database is managed, meaning that it is a component in the cluster topology.
     *
     * @return true if the DB is managed; false otherwise
     */
    private boolean isDatabaseManaged(Map<String, Map<String, String>> properties) {
      // conditional property should always exist since it is required to be specified in the stack
      return properties.get(configPropertyType).
        get(conditionalPropertyName).startsWith("New");
    }
  }

  /**
   * Topology based updater which replaces original host names (possibly more than one) contained in a property
   * value with the host names which runs the associated component in the new cluster.
   */
  protected static class MultipleHostTopologyUpdater implements PropertyUpdater {

    private static final Character DEFAULT_SEPARATOR = ',';

    /**
     * Component name
     */
    private final String component;

    /**
     * Separator for multiple property values
     */
    private final Character separator;

    /**
     * Flag to determine if a URL scheme detected as
     * a prefix in the property should be repeated across
     * all hosts in the property
     */
    private final boolean usePrefixForEachHost;

    private final boolean useSuffixForEachHost;

    private final boolean usePortForEachHost;

    /**
     * Constructor.
     *
     * @param component  component name associated with the property
     */
    public MultipleHostTopologyUpdater(String component) {
      this(component, DEFAULT_SEPARATOR, false, false, true);
    }

    /**
     * Constructor
     *
     * @param component component name associated with this property
     * @param separator the separator character to use when multiple hosts
     *                  are specified in a property or URL
     */
    public MultipleHostTopologyUpdater(String component, Character separator, boolean usePrefixForEachHost, boolean useSuffixForEachHost, boolean usePortForEachHost) {
      this.component = component;
      this.separator = separator;
      this.usePrefixForEachHost = usePrefixForEachHost;
      this.useSuffixForEachHost = useSuffixForEachHost;
      this.usePortForEachHost = usePortForEachHost;
    }

    /**
     * Update all host names included in the original property value with new host names which run the associated
     * component.
     *
     * @param propertyName property name
     * @param origValue    original value of property
     * @param properties   all properties
     * @param topology     cluster topology
     * @return updated property value with old host names replaced by new host names
     */
    @Override
    public String updateForClusterCreate(String propertyName,
                                         String origValue,
                                         Map<String, Map<String, String>> properties,
                                         ClusterTopology topology) {

      if (!origValue.contains("%HOSTGROUP") && (!origValue.contains(LOCALHOST))) {
        // this property must contain FQDNs specified directly by the user
        // of the Blueprint, so the processor should not attempt to update them
        return origValue;
      }

      Collection<String> hostStrings = getHostStrings(origValue, topology);
      hostStrings.addAll(getHostStringsFromLocalhost(origValue, topology));

      return resolveHostGroupPlaceholder(origValue, hostStrings);
    }

    /**
     * Gets the prefix for hosts
     * @param value property value
     * @return prefix
     */
    private String getPrefix(String value) {
      Matcher localhostMatcher = LOCALHOST_PORT_REGEX.matcher(value);
      Matcher hostGroupMatcher = HOSTGROUP_PORT_REGEX.matcher(value);
      String prefixCandidate = null;

      if(localhostMatcher.find()) {
        prefixCandidate = value.substring(0,localhostMatcher.start());
      } else if(hostGroupMatcher.find()) {
        prefixCandidate = value.substring(0,hostGroupMatcher.start());
      } else {
        return prefixCandidate;
      }

      // remove YAML array notation
      if(prefixCandidate.startsWith("[")) {
        prefixCandidate = prefixCandidate.substring(1);
      }
      // remove YAML string notation
      if(prefixCandidate.startsWith("'")) {
        prefixCandidate = prefixCandidate.substring(1);
      }

      return prefixCandidate;
    }

    /**
     * Gets the suffix for hosts
     * @param value property value
     * @return suffix
     */
    private String getSuffix(String value) {
      Matcher localhostMatcher = LOCALHOST_PORT_REGEX.matcher(value);
      Matcher hostGroupMatcher = HOSTGROUP_PORT_REGEX.matcher(value);


      Matcher activeMatcher = null;

      if(localhostMatcher.find()) {
        activeMatcher = localhostMatcher;
      } else if(hostGroupMatcher.find()) {
        activeMatcher = hostGroupMatcher;
      } else {
        return null;
      }

      String suffixCandidate = null;
      int indexOfEnd;
      do {
        indexOfEnd = activeMatcher.end();
      } while (activeMatcher.find());
      suffixCandidate = value.substring(indexOfEnd);

      // remove YAML array notation
      if(suffixCandidate.endsWith("]")) {
        suffixCandidate = suffixCandidate.substring(0, suffixCandidate.length()-1);
      }
      // remove YAML string notation
      if(suffixCandidate.endsWith("'")) {
        suffixCandidate = suffixCandidate.substring(0, suffixCandidate.length()-1);
      }

      return suffixCandidate;
    }

    /**
     * Resolves localhost value to "host:port" elements (port is optional)
     * @param origValue property value
     * @param topology cluster topology
     * @return list of hosts that have the given components
     */
    private Collection<String> getHostStringsFromLocalhost(String origValue, ClusterTopology topology) {
      Set<String> hostStrings = new HashSet<>();
      if(origValue.contains(LOCALHOST)) {
        Matcher localhostMatcher = LOCALHOST_PORT_REGEX.matcher(origValue);
        String port = null;
        if(localhostMatcher.find()) {
          port = calculatePort(localhostMatcher.group());
        }
        for (String host : topology.getHostAssignmentsForComponent(component)) {
          if (port != null) {
            host += ":" + port;
          }
          hostStrings.add(host);
        }
      }
      return hostStrings;
    }

    /**
     * Resolves the host group place holders in the passed in original value.
     * @param originalValue The original value containing the place holders to be resolved.
     * @param hostStrings The collection of host names that are mapped to the host groups to be resolved
     * @return The new value with place holders resolved.
     */
    protected String resolveHostGroupPlaceholder(String originalValue, Collection<String> hostStrings) {
      String prefix = getPrefix(originalValue);
      String suffix = getSuffix(originalValue);
      String port = removePorts(hostStrings);

      String sep = (useSuffixForEachHost ? suffix : "") + separator + (usePrefixForEachHost ? prefix : "");
      String combinedHosts = (usePrefixForEachHost ? prefix : "") + StringUtils.join(hostStrings, sep);

      return (usePrefixForEachHost ? "" : prefix) + combinedHosts + (usePortForEachHost || port == null ? "" : ":" + port) + suffix;
    }

    /**
     * Removes "port" part of the hosts and returns it
     * @param hostStrings list of "host:port" strings (port is optional)
     * @return the port
     */
    private String removePorts(Collection<String> hostStrings) {
      String port = null;
      if(!usePortForEachHost && !hostStrings.isEmpty()) {
        Set<String> temp = new HashSet<>();

        // extract port
        Iterator<String> i = hostStrings.iterator();
        do {
          port = calculatePort(i.next());
        } while (i.hasNext() && port == null);

        // update hosts
        if(port != null) {
          for(String host : hostStrings) {
            temp.add(host.replace(":"+port,""));
          }
        }
        hostStrings.clear();
        hostStrings.addAll(temp);
      }
      return port;
    }

    private static String calculatePort(String origValue) {
      if (origValue.contains(":")) {
        //todo: currently assuming all hosts are using same port
        return origValue.substring(origValue.indexOf(":") + 1);
      }

      return null;
    }

    @Override
    public Collection<String> getRequiredHostGroups(String propertyName,
                                                    String origValue,
                                                    Map<String, Map<String, String>> properties,
                                                    ClusterTopology topology) {

      Collection<String> requiredHostGroups = new HashSet<>();

      // add all host groups specified in host group tokens
      Matcher m = HOSTGROUP_PORT_REGEX.matcher(origValue);
      while (m.find()) {
        String groupName = m.group(1);

        if (!topology.getBlueprint().getHostGroups().containsKey(groupName)) {
          throw new IllegalArgumentException(
            "Unable to match blueprint host group token to a host group: " + groupName);
        }
        requiredHostGroups.add(groupName);
      }

      //todo: for now assuming that we will either have HG tokens or standard replacement but not both
      //todo: as is done in updateForClusterCreate
      if (requiredHostGroups.isEmpty()) {
        requiredHostGroups.addAll(topology.getHostGroupsForComponent(component));
      }

      return requiredHostGroups;
    }
  }

  /**
   * Class to facilitate special formatting needs of property values.
   */
  private abstract static class AbstractPropertyValueDecorator implements PropertyUpdater {
    PropertyUpdater propertyUpdater;

    /**
     * Constructor.
     *
     * @param propertyUpdater  wrapped updater
     */
    public AbstractPropertyValueDecorator(PropertyUpdater propertyUpdater) {
      this.propertyUpdater = propertyUpdater;
    }

    /**
     * Return decorated form of the updated input property value.
     *
     * @param propertyName  property name
     * @param origValue     original value of property
     * @param properties    all properties
     * @param topology      cluster topology
     *
     * @return Formatted output string
     */
    @Override
    public String updateForClusterCreate(String propertyName,
                                         String origValue,
                                         Map<String, Map<String, String>> properties,
                                         ClusterTopology topology) {

      // return customer-supplied properties without updating them
      if (isFQDNValue(origValue)) {
        return origValue;
      }

      return doFormat(propertyUpdater.updateForClusterCreate(propertyName, origValue, properties, topology));
    }

    /**
     * Transform input string to required output format.
     *
     * @param originalValue  original value of property
     *
     * @return formatted output string
     */
    public abstract String doFormat(String originalValue);

    @Override
    public Collection<String> getRequiredHostGroups(String propertyName,
                                                    String origValue,
                                                    Map<String, Map<String, String>> properties,
                                                    ClusterTopology topology) {

      return propertyUpdater.getRequiredHostGroups(propertyName, origValue, properties, topology);
    }

    /**
     * Convenience method to determine if a property value is a
     * customer-specified FQDN.
     *
     * @param value property value to examine
     * @return true if the property represents an FQDN value
     *         false if the property does not represent an FQDN value
     */
    public boolean isFQDNValue(String value) {
      return !value.contains("%HOSTGROUP") &&
        !value.contains(LOCALHOST);
    }
  }

  /**
   * Return properties of the form ['value']
   */
  static class YamlMultiValuePropertyDecorator extends AbstractPropertyValueDecorator {

    // currently, only plain and single-quoted Yaml flows are supported by this updater
    enum FlowStyle {
      SINGLE_QUOTED,
      PLAIN
    }

    /**
     * Regexp to extract the inner part of a string enclosed in []
     */
    private static Pattern REGEX_IN_BRACKETS = Pattern.compile("\\s*\\[(?<INNER>.*)\\]\\s*");
    /**
     * Regexp to extract the inner part of a string enclosed in ''
     */
    private static Pattern REGEX_IN_QUOTES = Pattern.compile("\\s*'(?<INNER>.*)'\\s*");

    private final FlowStyle flowStyle;

    public YamlMultiValuePropertyDecorator(PropertyUpdater propertyUpdater) {
      // single-quote style is considered default by this updater
      this(propertyUpdater, FlowStyle.SINGLE_QUOTED);
    }

    protected YamlMultiValuePropertyDecorator(PropertyUpdater propertyUpdater, FlowStyle flowStyle) {
      super(propertyUpdater);
      this.flowStyle = flowStyle;
    }

    /**
     * Format input String of the form, str1,str2 to ['str1','str2']
     * If the input string is already surrounded by [] ignore those
     * and process the part from within the square brackets.
     * @param origValue  input string
     *
     * @return formatted string
     */
    @Override
    public String doFormat(String origValue) {
      StringBuilder sb = new StringBuilder();

      Matcher m = REGEX_IN_BRACKETS.matcher(origValue);
      if (m.matches()) {
        origValue = m.group("INNER");
      }

      if (origValue != null) {
        sb.append("[");
        boolean isFirst = true;
        for (String value : origValue.split(",")) {

          m = REGEX_IN_QUOTES.matcher(value);
          if (m.matches()) {
            value = m.group("INNER");
          }

          if (!isFirst) {
            sb.append(",");
          } else {
            isFirst = false;
          }

          if (flowStyle == FlowStyle.SINGLE_QUOTED) {
            sb.append("'");
          }

          sb.append(value);

          if (flowStyle == FlowStyle.SINGLE_QUOTED) {
            sb.append("'");
          }

        }
        sb.append("]");
      }
      return sb.toString();
    }
  }

  /**
   * PropertyUpdater implementation that will always return the original
   *   value for the updateForClusterCreate() method.
   *   This updater type should only be used in cases where a given
   *   property requires no updates, but may need to be considered
   *   during the Blueprint export process.
   */
  private static class OriginalValuePropertyUpdater implements PropertyUpdater {

    @Override
    public String updateForClusterCreate(String propertyName,
                                         String origValue,
                                         Map<String, Map<String, String>> properties,
                                         ClusterTopology topology) {
      // always return the original value, since these properties do not require update handling
      return origValue;
    }

    @Override
    public Collection<String> getRequiredHostGroups(String propertyName,
                                                    String origValue,
                                                    Map<String, Map<String, String>> properties,
                                                    ClusterTopology topology) {

      return Collections.emptySet();
    }
  }

  /**
   * Custom PropertyUpdater that handles the parsing and updating of the
   * "templeton.hive.properties" configuration property for WebHCat.
   * This particular configuration property uses a format of
   * comma-separated key/value pairs.  The Values in the case of the
   * hive.metastores.uri property can also contain commas, and so character
   * escaping with a backslash (\) must take place during substitution.
   *
   */
  private static class TempletonHivePropertyUpdater implements PropertyUpdater {

    private Map<String, PropertyUpdater> mapOfKeysToUpdaters =
      new HashMap<>();

    TempletonHivePropertyUpdater() {
      // the only known property that requires hostname substitution is hive.metastore.uris,
      // but this updater should be flexible enough for other properties in the future.
      mapOfKeysToUpdaters.put("hive.metastore.uris", new MultipleHostTopologyUpdater("HIVE_METASTORE", ',', true, false, true));
    }

    @Override
    public String updateForClusterCreate(String propertyName,
                                         String origValue,
                                         Map<String, Map<String, String>> properties,
                                         ClusterTopology topology) {

      // short-circuit out any custom property values defined by the deployer
      if (!origValue.contains("%HOSTGROUP") &&
        (!origValue.contains(LOCALHOST))) {
        // this property must contain FQDNs specified directly by the user
        // of the Blueprint, so the processor should not attempt to update them
        return origValue;
      }

      StringBuilder updatedResult = new StringBuilder();
      // split out the key/value pairs
      String[] keyValuePairs = origValue.split(",");
      boolean firstValue = true;
      for (String keyValuePair : keyValuePairs) {
        keyValuePair = keyValuePair.trim();
        if (!firstValue) {
          updatedResult.append(",");
        } else {
          firstValue = false;
        }

        String key = keyValuePair.split("=")[0].trim();
        if (mapOfKeysToUpdaters.containsKey(key)) {
          String result = mapOfKeysToUpdaters.get(key).updateForClusterCreate(
            key, keyValuePair.split("=")[1].trim(), properties, topology);
          // append the internal property result, escape out any commas in the internal property,
          // this is required due to the specific syntax of templeton.hive.properties
          updatedResult.append(key);
          updatedResult.append("=");
          updatedResult.append(result.replaceAll(",", Matcher.quoteReplacement("\\,")));
        } else {
          updatedResult.append(keyValuePair);
        }
      }

      return updatedResult.toString();
    }

    @Override
    public Collection<String> getRequiredHostGroups(String propertyName,
                                                    String origValue,
                                                    Map<String, Map<String, String>> properties,
                                                    ClusterTopology topology) {

      // short-circuit out any custom property values defined by the deployer
      if (!origValue.contains("%HOSTGROUP") &&
        (!origValue.contains(LOCALHOST))) {
        // this property must contain FQDNs specified directly by the user
        // of the Blueprint, so the processor should not attempt to update them
        return Collections.emptySet();
      }

      Collection<String> requiredGroups = new HashSet<>();
      // split out the key/value pairs
      String[] keyValuePairs = origValue.split(",");
      for (String keyValuePair : keyValuePairs) {
        String key = keyValuePair.split("=")[0];
        if (mapOfKeysToUpdaters.containsKey(key)) {
          requiredGroups.addAll(mapOfKeysToUpdaters.get(key).getRequiredHostGroups(
            propertyName, keyValuePair.split("=")[1], properties, topology));
        }
      }
      return requiredGroups;
    }
  }

  /**
   * A topology independent updater which provides a default implementation of getRequiredHostGroups
   * since no topology related information is required by the updater.
   */
  private static abstract class NonTopologyUpdater implements PropertyUpdater {
    @Override
    public Collection<String> getRequiredHostGroups(String propertyName,
                                                    String origValue,
                                                    Map<String, Map<String, String>> properties,
                                                    ClusterTopology topology) {
      return Collections.emptyList();
    }
  }


  // Register updaters for configuration properties.
  static {

    allUpdaters.add(singleHostTopologyUpdaters);
    allUpdaters.add(multiHostTopologyUpdaters);
    allUpdaters.add(dbHostTopologyUpdaters);
    allUpdaters.add(mPropertyUpdaters);
    allUpdaters.add(nonTopologyUpdaters);

    Map<String, PropertyUpdater> amsSiteMap = new HashMap<>();
    Map<String, PropertyUpdater> druidCommon = new HashMap<>();
    Map<String, PropertyUpdater> hdfsSiteMap = new HashMap<>();
    Map<String, PropertyUpdater> mapredSiteMap = new HashMap<>();
    Map<String, PropertyUpdater> coreSiteMap = new HashMap<>();
    Map<String, PropertyUpdater> hbaseSiteMap = new HashMap<>();
    Map<String, PropertyUpdater> yarnSiteMap = new HashMap<>();
    Map<String, PropertyUpdater> hiveSiteMap = new HashMap<>();
    Map<String, PropertyUpdater> hiveSiteNonTopologyMap = new HashMap<>();
    Map<String, PropertyUpdater> hiveEnvOriginalValueMap = new HashMap<>();
    Map<String, PropertyUpdater> oozieSiteOriginalValueMap = new HashMap<>();
    Map<String, PropertyUpdater> oozieSiteMap = new HashMap<>();
    Map<String, PropertyUpdater> stormSiteMap = new HashMap<>();
    Map<String, PropertyUpdater> stormSiteNonTopologyMap = new HashMap<>();
    Map<String, PropertyUpdater> accumuloSiteMap = new HashMap<>();
    Map<String, PropertyUpdater> falconStartupPropertiesMap = new HashMap<>();
    Map<String, PropertyUpdater> kafkaBrokerMap = new HashMap<>();
    Map<String, PropertyUpdater> kafkaBrokerNonTopologyMap = new HashMap<>();
    Map<String, PropertyUpdater> atlasPropsMap = new HashMap<>();
    Map<String, PropertyUpdater> mapredEnvMap = new HashMap<>();
    Map<String, PropertyUpdater> mHadoopEnvMap = new HashMap<>();
    Map<String, PropertyUpdater> shHadoopEnvMap = new HashMap<>();
    Map<String, PropertyUpdater> clusterEnvMap = new HashMap<>();
    Map<String, PropertyUpdater> hbaseEnvMap = new HashMap<>();
    Map<String, PropertyUpdater> hiveEnvMap = new HashMap<>();
    Map<String, PropertyUpdater> hiveInteractiveEnvMap = new HashMap<>();
    Map<String, PropertyUpdater> hiveInteractiveSiteMap = new HashMap<>();
    Map<String, PropertyUpdater> oozieEnvMap = new HashMap<>();
    Map<String, PropertyUpdater> oozieEnvHeapSizeMap = new HashMap<>();
    Map<String, PropertyUpdater> multiWebhcatSiteMap = new HashMap<>();
    Map<String, PropertyUpdater> multiHbaseSiteMap = new HashMap<>();
    Map<String, PropertyUpdater> livy2Conf = new HashMap<>();
    Map<String, PropertyUpdater> multiStormSiteMap = new HashMap<>();
    Map<String, PropertyUpdater> multiCoreSiteMap = new HashMap<>();
    Map<String, PropertyUpdater> multiHdfsSiteMap = new HashMap<>();
    Map<String, PropertyUpdater> multiHiveSiteMap = new HashMap<>();
    Map<String, PropertyUpdater> multiKafkaBrokerMap = new HashMap<>();
    Map<String, PropertyUpdater> multiYarnSiteMap = new HashMap<>();
    Map<String, PropertyUpdater> multiOozieSiteMap = new HashMap<>();
    Map<String, PropertyUpdater> multiAccumuloSiteMap = new HashMap<>();
    Map<String, PropertyUpdater> multiRangerKmsSiteMap = new HashMap<>();
    Map<String, PropertyUpdater> dbHiveSiteMap = new HashMap<>();
    Map<String, PropertyUpdater> rangerAdminPropsMap = new HashMap<>();
    Map<String, PropertyUpdater> rangerEnvPropsMap = new HashMap<>();
    Map<String, PropertyUpdater> rangerYarnAuditPropsMap = new HashMap<>();
    Map<String, PropertyUpdater> rangerHdfsAuditPropsMap = new HashMap<>();
    Map<String, PropertyUpdater> rangerHbaseAuditPropsMap = new HashMap<>();
    Map<String, PropertyUpdater> rangerHiveAuditPropsMap = new HashMap<>();
    Map<String, PropertyUpdater> rangerKnoxAuditPropsMap = new HashMap<>();
    Map<String, PropertyUpdater> rangerKafkaAuditPropsMap = new HashMap<>();
    Map<String, PropertyUpdater> rangerStormAuditPropsMap = new HashMap<>();
    Map<String, PropertyUpdater> rangerAtlasAuditPropsMap = new HashMap<>();
    Map<String, PropertyUpdater> hawqSiteMap = new HashMap<>();
    Map<String, PropertyUpdater> zookeeperEnvMap = new HashMap<>();

    singleHostTopologyUpdaters.put("ams-site", amsSiteMap);
    singleHostTopologyUpdaters.put("druid-common", druidCommon);
    singleHostTopologyUpdaters.put("hdfs-site", hdfsSiteMap);
    singleHostTopologyUpdaters.put("mapred-site", mapredSiteMap);
    singleHostTopologyUpdaters.put("core-site", coreSiteMap);
    singleHostTopologyUpdaters.put("hbase-site", hbaseSiteMap);
    singleHostTopologyUpdaters.put("yarn-site", yarnSiteMap);
    singleHostTopologyUpdaters.put("hive-site", hiveSiteMap);
    singleHostTopologyUpdaters.put("hive-interactive-env", hiveInteractiveEnvMap);
    singleHostTopologyUpdaters.put("storm-site", stormSiteMap);
    singleHostTopologyUpdaters.put("accumulo-site", accumuloSiteMap);
    singleHostTopologyUpdaters.put("falcon-startup.properties", falconStartupPropertiesMap);
    singleHostTopologyUpdaters.put("hive-env", hiveEnvMap);
    singleHostTopologyUpdaters.put("oozie-env", oozieEnvMap);
    singleHostTopologyUpdaters.put("kafka-broker", kafkaBrokerMap);
    singleHostTopologyUpdaters.put("admin-properties", rangerAdminPropsMap);
    singleHostTopologyUpdaters.put("ranger-env", rangerEnvPropsMap);
    singleHostTopologyUpdaters.put("ranger-yarn-audit", rangerYarnAuditPropsMap);
    singleHostTopologyUpdaters.put("ranger-hdfs-audit", rangerHdfsAuditPropsMap);
    singleHostTopologyUpdaters.put("ranger-hbase-audit", rangerHbaseAuditPropsMap);
    singleHostTopologyUpdaters.put("ranger-hive-audit", rangerHiveAuditPropsMap);
    singleHostTopologyUpdaters.put("ranger-knox-audit", rangerKnoxAuditPropsMap);
    singleHostTopologyUpdaters.put("ranger-kafka-audit", rangerKafkaAuditPropsMap);
    singleHostTopologyUpdaters.put("ranger-storm-audit", rangerStormAuditPropsMap);
    singleHostTopologyUpdaters.put("ranger-atlas-audit", rangerAtlasAuditPropsMap);
    singleHostTopologyUpdaters.put(HADOOP_ENV_CONFIG_TYPE_NAME, shHadoopEnvMap);
    singleHostTopologyUpdaters.put(CLUSTER_ENV_CONFIG_TYPE_NAME, clusterEnvMap);

    singleHostTopologyUpdaters.put("hawq-site", hawqSiteMap);
    singleHostTopologyUpdaters.put("zookeeper-env", zookeeperEnvMap);


    mPropertyUpdaters.put(HADOOP_ENV_CONFIG_TYPE_NAME, mHadoopEnvMap);
    mPropertyUpdaters.put("hbase-env", hbaseEnvMap);
    mPropertyUpdaters.put("mapred-env", mapredEnvMap);
    mPropertyUpdaters.put("oozie-env", oozieEnvHeapSizeMap);

    multiHostTopologyUpdaters.put("webhcat-site", multiWebhcatSiteMap);
    multiHostTopologyUpdaters.put("hbase-site", multiHbaseSiteMap);
    multiHostTopologyUpdaters.put("storm-site", multiStormSiteMap);
    multiHostTopologyUpdaters.put("core-site", multiCoreSiteMap);
    multiHostTopologyUpdaters.put("hdfs-site", multiHdfsSiteMap);
    multiHostTopologyUpdaters.put("hive-site", multiHiveSiteMap);
    multiHostTopologyUpdaters.put("hive-interactive-site", hiveInteractiveSiteMap);
    multiHostTopologyUpdaters.put("kafka-broker", multiKafkaBrokerMap);
    multiHostTopologyUpdaters.put("yarn-site", multiYarnSiteMap);
    multiHostTopologyUpdaters.put("oozie-site", multiOozieSiteMap);
    multiHostTopologyUpdaters.put("accumulo-site", multiAccumuloSiteMap);
    multiHostTopologyUpdaters.put("kms-site", multiRangerKmsSiteMap);
    multiHostTopologyUpdaters.put("application-properties", atlasPropsMap);
    multiHostTopologyUpdaters.put("livy2-conf", livy2Conf);

    dbHostTopologyUpdaters.put("hive-site", dbHiveSiteMap);

    nonTopologyUpdaters.put("hive-site", hiveSiteNonTopologyMap);
    nonTopologyUpdaters.put("kafka-broker", kafkaBrokerNonTopologyMap);
    nonTopologyUpdaters.put("storm-site", stormSiteNonTopologyMap);

    //todo: Need to change updaters back to being static
    //todo: will need to pass ClusterTopology in as necessary


    // NAMENODE
    hdfsSiteMap.put("dfs.http.address", new OptionalSingleHostTopologyUpdater("NAMENODE"));
    hdfsSiteMap.put("dfs.https.address", new OptionalSingleHostTopologyUpdater("NAMENODE"));
    coreSiteMap.put("fs.default.name", new OptionalSingleHostTopologyUpdater("NAMENODE"));
    hdfsSiteMap.put("dfs.namenode.http-address", new OptionalSingleHostTopologyUpdater("NAMENODE"));
    hdfsSiteMap.put("dfs.namenode.https-address", new OptionalSingleHostTopologyUpdater("NAMENODE"));
    hdfsSiteMap.put("dfs.namenode.rpc-address", new OptionalSingleHostTopologyUpdater("NAMENODE"));
    coreSiteMap.put("fs.defaultFS", new OptionalSingleHostTopologyUpdater("NAMENODE"));
    hbaseSiteMap.put("hbase.rootdir", new OptionalSingleHostTopologyUpdater("NAMENODE"));
    accumuloSiteMap.put("instance.volumes", new SingleHostTopologyUpdater("NAMENODE"));
    // HDFS shared.edits JournalNode Quorum URL uses semi-colons as separators
    multiHdfsSiteMap.put("dfs.namenode.shared.edits.dir", new MultipleHostTopologyUpdater("JOURNALNODE", ';', false, false, true));
    multiHdfsSiteMap.put("dfs.encryption.key.provider.uri", new MultipleHostTopologyUpdater("RANGER_KMS_SERVER", ';', false, false, false));
    // Explicit initial primary/secondary node assignment in HA
    clusterEnvMap.put(HDFS_ACTIVE_NAMENODE_PROPERTY_NAME, new SingleHostTopologyUpdater("NAMENODE"));
    clusterEnvMap.put(HDFS_STANDBY_NAMENODE_PROPERTY_NAME, new SingleHostTopologyUpdater("NAMENODE"));

    // SECONDARY_NAMENODE
    hdfsSiteMap.put("dfs.secondary.http.address", new OptionalSingleHostTopologyUpdater("SECONDARY_NAMENODE"));
    hdfsSiteMap.put("dfs.namenode.secondary.http-address", new OptionalSingleHostTopologyUpdater("SECONDARY_NAMENODE"));

    // JOBTRACKER
    mapredSiteMap.put("mapred.job.tracker", new SingleHostTopologyUpdater("JOBTRACKER"));
    mapredSiteMap.put("mapred.job.tracker.http.address", new SingleHostTopologyUpdater("JOBTRACKER"));
    mapredSiteMap.put("mapreduce.history.server.http.address", new SingleHostTopologyUpdater("JOBTRACKER"));
    mapredSiteMap.put("mapreduce.job.hdfs-servers", new SingleHostTopologyUpdater("NAMENODE"));


    // HISTORYSERVER
    yarnSiteMap.put("yarn.log.server.url", new OptionalSingleHostTopologyUpdater("HISTORYSERVER"));
    mapredSiteMap.put("mapreduce.jobhistory.webapp.address", new OptionalSingleHostTopologyUpdater("HISTORYSERVER"));
    mapredSiteMap.put("mapreduce.jobhistory.address", new OptionalSingleHostTopologyUpdater("HISTORYSERVER"));

    // RESOURCEMANAGER
    yarnSiteMap.put("yarn.resourcemanager.hostname", new OptionalSingleHostTopologyUpdater("RESOURCEMANAGER"));
    yarnSiteMap.put("yarn.resourcemanager.resource-tracker.address", new OptionalSingleHostTopologyUpdater("RESOURCEMANAGER"));
    yarnSiteMap.put("yarn.resourcemanager.webapp.address", new OptionalSingleHostTopologyUpdater("RESOURCEMANAGER"));
    yarnSiteMap.put("yarn.resourcemanager.scheduler.address", new OptionalSingleHostTopologyUpdater("RESOURCEMANAGER"));
    yarnSiteMap.put("yarn.resourcemanager.address", new OptionalSingleHostTopologyUpdater("RESOURCEMANAGER"));
    yarnSiteMap.put("yarn.resourcemanager.admin.address", new OptionalSingleHostTopologyUpdater("RESOURCEMANAGER"));
    yarnSiteMap.put("yarn.resourcemanager.webapp.https.address", new OptionalSingleHostTopologyUpdater("RESOURCEMANAGER"));

    // APP_TIMELINE_SERVER
    yarnSiteMap.put("yarn.timeline-service.address", new OptionalSingleHostTopologyUpdater("APP_TIMELINE_SERVER"));
    yarnSiteMap.put("yarn.timeline-service.webapp.address", new OptionalSingleHostTopologyUpdater("APP_TIMELINE_SERVER"));
    yarnSiteMap.put("yarn.timeline-service.webapp.https.address", new OptionalSingleHostTopologyUpdater("APP_TIMELINE_SERVER"));
    yarnSiteMap.put("yarn.log.server.web-service.url", new OptionalSingleHostTopologyUpdater("APP_TIMELINE_SERVER"));

    // TIMELINE_READER
    yarnSiteMap.put("yarn.timeline-service.reader.webapp.address", new MultipleHostTopologyUpdater("TIMELINE_READER"));
    yarnSiteMap.put("yarn.timeline-service.reader.webapp.https.address", new MultipleHostTopologyUpdater("TIMELINE_READER"));

    // HIVE_SERVER
    hiveSiteMap.put("hive.server2.authentication.ldap.url", new SingleHostTopologyUpdater("HIVE_SERVER2"));
    multiHiveSiteMap.put("hive.metastore.uris", new MultipleHostTopologyUpdater("HIVE_METASTORE", ',', true, true, true));
    dbHiveSiteMap.put("javax.jdo.option.ConnectionURL",
      new DBTopologyUpdater("MYSQL_SERVER", "hive-env", "hive_database"));
    multiCoreSiteMap.put("hadoop.proxyuser.hive.hosts", new MultipleHostTopologyUpdater("HIVE_SERVER"));
    multiCoreSiteMap.put("hadoop.proxyuser.HTTP.hosts", new MultipleHostTopologyUpdater("WEBHCAT_SERVER"));
    multiCoreSiteMap.put("hadoop.proxyuser.hcat.hosts", new MultipleHostTopologyUpdater("WEBHCAT_SERVER"));
    multiCoreSiteMap.put("hadoop.proxyuser.yarn.hosts", new MultipleHostTopologyUpdater("RESOURCEMANAGER"));
    multiCoreSiteMap.put("hadoop.security.key.provider.path", new MultipleHostTopologyUpdater("RANGER_KMS_SERVER", ';', false, false, true));
    multiWebhcatSiteMap.put("templeton.hive.properties", new TempletonHivePropertyUpdater());
    multiHiveSiteMap.put("hive.zookeeper.quorum", new MultipleHostTopologyUpdater("ZOOKEEPER_SERVER"));
    multiHiveSiteMap.put("hive.cluster.delegation.token.store.zookeeper.connectString", new MultipleHostTopologyUpdater("ZOOKEEPER_SERVER"));

    // HIVE Interactive Server
    hiveInteractiveEnvMap.put("hive_server_interactive_host", new SingleHostTopologyUpdater("HIVE_SERVER_INTERACTIVE"));
    hiveInteractiveSiteMap.put("hive.llap.zk.sm.connectionString", new MultipleHostTopologyUpdater("ZOOKEEPER_SERVER"));

    // HIVE Atlas integration
    hiveSiteNonTopologyMap.put("hive.exec.post.hooks", new NonTopologyUpdater() {
      @Override
      public String updateForClusterCreate(String propertyName,
                                           String origValue,
                                           Map<String, Map<String, String>> properties,
                                           ClusterTopology topology) {
        String atlasHookClass = "org.apache.atlas.hive.hook.HiveHook";
        String[] hiveHooks = origValue.split(",");

        List<String> hiveHooksClean = new ArrayList<>();
        for(String hiveHook : hiveHooks) {
          if (!StringUtils.isBlank(hiveHook.trim())) {
            hiveHooksClean.add(hiveHook.trim());
          }
        }

        boolean isAtlasInCluster = topology.getBlueprint().getServices().contains("ATLAS");
        boolean isAtlasHiveHookEnabled = Boolean.parseBoolean(properties.get("hive-env").get("hive.atlas.hook"));

        // Append atlas hook if not already present.
        if (isAtlasInCluster || isAtlasHiveHookEnabled) {
          if (!hiveHooksClean.contains(atlasHookClass)) {
            hiveHooksClean.add(atlasHookClass);
          }
        } else {
          // Remove the atlas hook since Atlas service is not present.
          while (hiveHooksClean.contains(atlasHookClass)) {
            hiveHooksClean.remove(atlasHookClass);
          }
        }

        if (!hiveHooksClean.isEmpty()) {
          return StringUtils.join(hiveHooksClean, ",");
        } else {
          return " ";
        }
      }
    });

    // TODO AMBARI-17782, remove this property from hive-site only in HDP 2.5 and higher.
    hiveSiteNonTopologyMap.put("atlas.cluster.name", new NonTopologyUpdater() {
      @Override
      public String updateForClusterCreate(String propertyName,
                                           String origValue,
                                           Map<String, Map<String, String>> properties,
                                           ClusterTopology topology) {

        if (topology.getBlueprint().getServices().contains("ATLAS")) {
          // if original value is not set or is the default "primary" set the cluster id
          if (origValue == null || origValue.trim().isEmpty() || origValue.equals("primary")) {
            //use cluster id because cluster name may change
            return String.valueOf(topology.getClusterId());
          } else {
            // if explicitly set by user, don't override
            return origValue;
          }
        } else {
          return origValue;
        }
      }

      @Override
      public String updateForBlueprintExport(String propertyName,
                                             String origValue,
                                             Map<String, Map<String, String>> properties,
                                             ClusterTopology topology) {

        // if the value is the cluster id, then update to primary
        if (origValue.equals(String.valueOf(topology.getClusterId()))) {
          return "primary";
        }
        return origValue;
      }
    });

    // TODO AMBARI-17782, remove this property only from HDP 2.5 and higher.
    hiveSiteMap.put("atlas.rest.address", new SingleHostTopologyUpdater("ATLAS_SERVER") {
      @Override
      public String updateForClusterCreate(String propertyName,
                                           String origValue,
                                           Map<String, Map<String, String>> properties,
                                           ClusterTopology topology) {
        if (topology.getBlueprint().getServices().contains("ATLAS")) {
          String host = topology.getHostAssignmentsForComponent("ATLAS_SERVER").iterator().next();

          boolean tlsEnabled = Boolean.parseBoolean(properties.get("application-properties").get("atlas.enableTLS"));
          String scheme;
          String port;
          if (tlsEnabled) {
            scheme = "https";
            port = properties.get("application-properties").get("atlas.server.https.port");
          } else {
            scheme = "http";
            port = properties.get("application-properties").get("atlas.server.http.port");
          }

          return String.format("%s://%s:%s", scheme, host, port);
        }
        return origValue;
      }
    });


    // OOZIE_SERVER
    Map<String, PropertyUpdater> oozieStringPropertyUpdaterMap = singleHostTopologyUpdaters.get("oozie-site");
    if (oozieStringPropertyUpdaterMap == null) {
      oozieStringPropertyUpdaterMap = new HashMap<>();
    }
    oozieStringPropertyUpdaterMap.put("oozie.base.url", new SingleHostTopologyUpdater("OOZIE_SERVER"));
    singleHostTopologyUpdaters.put("oozie-site", oozieStringPropertyUpdaterMap);

    multiCoreSiteMap.put("hadoop.proxyuser.oozie.hosts", new MultipleHostTopologyUpdater("OOZIE_SERVER"));

    // ZOOKEEPER_SERVER
    multiHbaseSiteMap.put("hbase.zookeeper.quorum", new MultipleHostTopologyUpdater("ZOOKEEPER_SERVER"));
    multiWebhcatSiteMap.put("templeton.zookeeper.hosts", new MultipleHostTopologyUpdater("ZOOKEEPER_SERVER"));
    multiCoreSiteMap.put("ha.zookeeper.quorum", new MultipleHostTopologyUpdater("ZOOKEEPER_SERVER"));
    multiYarnSiteMap.put("hadoop.registry.zk.quorum", new MultipleHostTopologyUpdater("ZOOKEEPER_SERVER"));
    multiYarnSiteMap.put("yarn.resourcemanager.zk-address", new MultipleHostTopologyUpdater("ZOOKEEPER_SERVER"));
    multiKafkaBrokerMap.put("zookeeper.connect", new MultipleHostTopologyUpdater("ZOOKEEPER_SERVER"));
    multiAccumuloSiteMap.put("instance.zookeeper.host", new MultipleHostTopologyUpdater("ZOOKEEPER_SERVER"));

    // STORM
    stormSiteMap.put("nimbus.host", new SingleHostTopologyUpdater("NIMBUS"));
    stormSiteMap.put("nimbus_hosts", new SingleHostTopologyUpdater("NIMBUS"));
    stormSiteMap.put("drpc_server_host", new SingleHostTopologyUpdater("DRPC_SERVER"));
    stormSiteMap.put("drpc.servers", new SingleHostTopologyUpdater("DRPC_SERVER"));
    stormSiteMap.put("storm_ui_server_host", new SingleHostTopologyUpdater("STORM_UI_SERVER"));
    stormSiteMap.put("worker.childopts", new OptionalSingleHostTopologyUpdater("GANGLIA_SERVER"));
    stormSiteMap.put("supervisor.childopts", new OptionalSingleHostTopologyUpdater("GANGLIA_SERVER"));
    stormSiteMap.put("nimbus.childopts", new OptionalSingleHostTopologyUpdater("GANGLIA_SERVER"));
    // Storm AMS integration
    stormSiteNonTopologyMap.put("metrics.reporter.register", new NonTopologyUpdater() {
      @Override
      public String updateForClusterCreate(String propertyName,
                                           String origValue,
                                           Map<String, Map<String, String>> properties,
                                           ClusterTopology topology) {

        if (topology.getBlueprint().getServices().contains("AMBARI_METRICS")) {
          final String amsReporterClass = "org.apache.hadoop.metrics2.sink.storm.StormTimelineMetricsReporter";
          if (origValue == null || origValue.isEmpty()) {
            return amsReporterClass;
          }
        }
        return origValue;
      }
    });

    multiStormSiteMap.put("supervisor_hosts",
      new YamlMultiValuePropertyDecorator(new MultipleHostTopologyUpdater("SUPERVISOR")));
    multiStormSiteMap.put("storm.zookeeper.servers",
      new YamlMultiValuePropertyDecorator(new MultipleHostTopologyUpdater("ZOOKEEPER_SERVER")));
    multiStormSiteMap.put("nimbus.seeds",
      new YamlMultiValuePropertyDecorator(new MultipleHostTopologyUpdater("NIMBUS"), YamlMultiValuePropertyDecorator.FlowStyle.PLAIN));


    // FALCON
    falconStartupPropertiesMap.put("*.broker.url", new SingleHostTopologyUpdater("FALCON_SERVER"));

    // KAFKA
    kafkaBrokerMap.put("kafka.ganglia.metrics.host", new OptionalSingleHostTopologyUpdater("GANGLIA_SERVER"));
    // KAFKA AMS integration
    kafkaBrokerNonTopologyMap.put("kafka.metrics.reporters", new NonTopologyUpdater() {
      @Override
      public String updateForClusterCreate(String propertyName,
                                           String origValue,
                                           Map<String, Map<String, String>> properties,
                                           ClusterTopology topology) {

        if (topology.getBlueprint().getServices().contains("AMBARI_METRICS")) {
          final String amsReportesClass = "org.apache.hadoop.metrics2.sink.kafka.KafkaTimelineMetricsReporter";
          if (origValue == null || origValue.isEmpty()) {
            return amsReportesClass;
          } else if (!origValue.contains(amsReportesClass)) {
            return String.format("%s,%s", origValue, amsReportesClass);
          }
        }
        return origValue;
      }
    });

    // KNOX
    multiCoreSiteMap.put("hadoop.proxyuser.knox.hosts", new MultipleHostTopologyUpdater("KNOX_GATEWAY"));
    multiWebhcatSiteMap.put("webhcat.proxyuser.knox.hosts", new MultipleHostTopologyUpdater("KNOX_GATEWAY"));
    multiOozieSiteMap.put("hadoop.proxyuser.knox.hosts", new MultipleHostTopologyUpdater("KNOX_GATEWAY"));
    multiOozieSiteMap.put("oozie.service.ProxyUserService.proxyuser.knox.hosts", new MultipleHostTopologyUpdater("KNOX_GATEWAY"));

    // ATLAS
    atlasPropsMap.put("atlas.server.bind.address", new MultipleHostTopologyUpdater("ATLAS_SERVER"));
    atlasPropsMap.put("atlas.rest.address", new MultipleHostTopologyUpdater("ATLAS_SERVER", ',', true, true, true));
    atlasPropsMap.put("atlas.kafka.bootstrap.servers", new MultipleHostTopologyUpdater("KAFKA_BROKER"));
    atlasPropsMap.put("atlas.kafka.zookeeper.connect", new MultipleHostTopologyUpdater("ZOOKEEPER_SERVER"));
    atlasPropsMap.put("atlas.graph.index.search.solr.zookeeper-url", new MultipleHostTopologyUpdater("ZOOKEEPER_SERVER", ',', false, true, true));
    atlasPropsMap.put("atlas.graph.storage.hostname", new MultipleHostTopologyUpdater("ZOOKEEPER_SERVER"));
    atlasPropsMap.put("atlas.audit.hbase.zookeeper.quorum", new MultipleHostTopologyUpdater("ZOOKEEPER_SERVER"));

    // RANGER_ADMIN
    rangerAdminPropsMap.put("policymgr_external_url", new SingleHostTopologyUpdater("RANGER_ADMIN"));

    // RANGER ENV
    List<Map<String, PropertyUpdater>> configsWithRangerHdfsAuditDirProperty = ImmutableList.of(
      rangerEnvPropsMap,
      rangerYarnAuditPropsMap,
      rangerHdfsAuditPropsMap,
      rangerHbaseAuditPropsMap,
      rangerHiveAuditPropsMap,
      rangerKnoxAuditPropsMap,
      rangerKafkaAuditPropsMap,
      rangerStormAuditPropsMap,
      rangerAtlasAuditPropsMap
    );
    for (Map<String, PropertyUpdater> rangerAuditPropsMap: configsWithRangerHdfsAuditDirProperty) {
      rangerAuditPropsMap.put("xasecure.audit.destination.hdfs.dir", new OptionalSingleHostTopologyUpdater("NAMENODE"));
      // the same prop updater must be used as for fs.defaultFS in core-site
    }

    // RANGER KMS
    multiRangerKmsSiteMap.put("hadoop.kms.authentication.signer.secret.provider.zookeeper.connection.string",
      new MultipleHostTopologyUpdater("ZOOKEEPER_SERVER"));
    // Required due to AMBARI-4933.  These no longer seem to be required as the default values in the stack
    // are now correct but are left here in case an existing blueprint still contains an old value.
    addUnitPropertyUpdaters();

    hawqSiteMap.put("hawq_master_address_host", new SingleHostTopologyUpdater("HAWQMASTER"));
    hawqSiteMap.put("hawq_standby_address_host", new SingleHostTopologyUpdater("HAWQSTANDBY"));
    hawqSiteMap.put("hawq_dfs_url", new SingleHostTopologyUpdater("NAMENODE"));

    // AMS
    amsSiteMap.put("timeline.metrics.service.webapp.address", new SingleHostTopologyUpdater("METRICS_COLLECTOR") {
      @Override
      public String updateForClusterCreate(String propertyName, String origValue, Map<String, Map<String, String>> properties, ClusterTopology topology) {
        if (!origValue.startsWith(BIND_ALL_IP_ADDRESS)) {
          return origValue.replace(origValue.split(":")[0], BIND_ALL_IP_ADDRESS);
        } else {
          return origValue;
        }
      }
    });

    // DRUID
    druidCommon.put("metastore_hostname", HostGroupUpdater.INSTANCE);
    druidCommon.put("druid.metadata.storage.connector.connectURI", HostGroupUpdater.INSTANCE);
    druidCommon.put("druid.zk.service.host", new MultipleHostTopologyUpdater("ZOOKEEPER_SERVER"));

    livy2Conf.put("livy.server.recovery.state-store.url", new MultipleHostTopologyUpdater("ZOOKEEPER_SERVER"));
  }

  private static void addUnitPropertyUpdaters() {
    Map<String, List<UnitValidatedProperty>> propsPerConfigType = UnitValidatedProperty.ALL
      .stream()
      .collect(groupingBy(UnitValidatedProperty::getConfigType));
    for (String configType : propsPerConfigType.keySet()) {
      Map<String, PropertyUpdater> unitUpdaters = new HashMap<>();
      for (UnitValidatedProperty each : propsPerConfigType.get(configType)) {
        unitUpdaters.put(each.getPropertyName(), new UnitUpdater(each.getServiceName(), each.getConfigType()));
      }
      mPropertyUpdaters.put(configType, unitUpdaters);
    }
  }

  /**
   * Generates property names of the format "hadoop.proxyuser.*" based on actual usernames defined in {@code configuration}.
   * Eg. if "hive-env" defined "hive_user": "cstm-hive", then a generated property name would be "hadoop_proxyuser_cstm-hive_hosts"
   * @return set of hadoop proxyuser property names, paired with the name of the config type the username is defined in
   *         (the config type is needed for filtering later)
   */
  private static Set<Pair<String, String>> generateHadoopProxyUserPropertyNames(Configuration configuration) {
    Set<Pair<String, String>> proxyUsers = new HashSet<>();
    Map<String, Map<String, String>> existingProperties = configuration.getFullProperties();
    for (Pair<String, String> userProp : PROPERTIES_FOR_HADOOP_PROXYUSER) {
      String configType = userProp.getLeft();
      String property = userProp.getRight();
      Map<String, String> configs = existingProperties.get(configType);
      if (configs != null) {
        String user = configs.get(property);
        if (!Strings.isNullOrEmpty(user)) {
          proxyUsers.add(Pair.of(configType, String.format(HADOOP_PROXYUSER_HOSTS_FORMAT, user)));
          proxyUsers.add(Pair.of(configType, String.format(HADOOP_PROXYUSER_GROUPS_FORMAT, user)));
        }
      }
    }

    return proxyUsers;
  }

  /**
   * Ensures {@code hadoop.proxyuser.*} properties are present in core-site for the services defined in the blueprint.
   */
  private static void setupHDFSProxyUsers(Configuration configuration, Set<String> configTypesUpdated, Collection<String> services) {
    if (services.contains("HDFS")) {
      Set<Pair<String, String>> configTypePropertyPairs = generateHadoopProxyUserPropertyNames(configuration);
      Set<String> acceptableConfigTypes = getEligibleConfigTypesForHadoopProxyUsers(services);

      Map<String, Map<String, String>> existingProperties = configuration.getFullProperties();
      for (Pair<String, String> pair : configTypePropertyPairs) {
        String configType = pair.getLeft();
        if (acceptableConfigTypes.contains(configType)) {
          Map<String, String> configs = existingProperties.get(configType);
          if (configs != null) {
            ensureProperty(configuration, "core-site", pair.getRight(), "*", configTypesUpdated);
          }
        }
      }
    }
  }

  /**
   * @return set of config types with eligible properties for hadoop proxyuser
   */
  private static Set<String> getEligibleConfigTypesForHadoopProxyUsers(Collection<String> services) {
    Set<String> acceptableConfigTypes = new HashSet<>();

    if (services.contains("OOZIE")) {
      acceptableConfigTypes.add("oozie-env");
    }

    if (services.contains("HIVE")) {
      acceptableConfigTypes.add("hive-env");
    }

    if (services.contains("HBASE")) {
      acceptableConfigTypes.add("hbase-env");
    }

    if (services.contains("FALCON")) {
      acceptableConfigTypes.add("falcon-env");
    }

    return acceptableConfigTypes;
  }

  /**
   * Adds properties from excluded config files (marked as excluded in service metainfo.xml) like Falcon related properties
   * from oozie-site.xml defined in FALCON/configuration. (AMBARI-13017)
   *
   * In case the excluded config-type related service is not present in the blueprint, excluded configs are ignored
   * @param configuration
   * @param configTypesUpdated
   * @param stack
   */
  private void addExcludedConfigProperties(Configuration configuration, Set<String> configTypesUpdated, Stack stack) {
    Collection<String> blueprintServices = clusterTopology.getBlueprint().getServices();

    LOG.debug("Handling excluded properties for blueprint services: {}", blueprintServices);

    for (String blueprintService : blueprintServices) {

      LOG.debug("Handling excluded properties for blueprint service: {}", blueprintService);
      Set<String> excludedConfigTypes = stack.getExcludedConfigurationTypes(blueprintService);

      if (excludedConfigTypes.isEmpty()) {
        LOG.debug("There are no excluded config types for blueprint service: {}", blueprintService);
        continue;
      }

      for(String configType: excludedConfigTypes) {
        LOG.debug("Handling excluded config type [{}] for blueprint service: [{}]", configType, blueprintService);

        String blueprintServiceForExcludedConfig;

        try {
          blueprintServiceForExcludedConfig = stack.getServiceForConfigType(configType);
        } catch (IllegalArgumentException illegalArgumentException) {
          LOG.warn("Error encountered while trying to obtain the service name for config type [" + configType +
            "].  Further processing on this excluded config type will be skipped.  " +
            "This usually means that a service's definitions have been manually removed from the Ambari stack definitions.  " +
            "If the stack definitions have not been changed manually, this may indicate a stack definition error in Ambari.  ", illegalArgumentException);
          // skip this type for any further processing
          continue;
        }


        if (!blueprintServices.contains(blueprintServiceForExcludedConfig)) {
          LOG.debug("Service [{}] for excluded config type [{}] is not present in the blueprint. " +
            "Ignoring excluded config entries.", blueprintServiceForExcludedConfig, configType);
          continue;
        }

        Map<String, String> configProperties = stack.getConfigurationProperties(blueprintService, configType);
        for(Map.Entry<String, String> entry: configProperties.entrySet()) {
          LOG.debug("ADD property {} {} {}", configType, entry.getKey(), entry.getValue());
          ensureProperty(configuration, configType, entry.getKey(), entry.getValue(), configTypesUpdated);
        }
      }
    }
  }

  /**
   * This method ensures that Ambari command retry is enabled if not explicitly overridden in
   * cluster-env by the Blueprint or Cluster Creation template.  The new dynamic provisioning model
   * requires that retry be enabled for most multi-node clusters, to this method sets reasonable defaults
   * in order to preserve backwards compatibility and to simplify Blueprint creation.
   *
   * If the retry-specific properties in cluster-env are not set, then the config processor
   * will set these values to defaults in cluster-env.
   *
   * @param configuration cluster configuration
   */
  private static void setRetryConfiguration(Configuration configuration, Set<String> configTypesUpdated) {
    boolean wasUpdated = false;

    if (configuration.getPropertyValue(CLUSTER_ENV_CONFIG_TYPE_NAME, COMMAND_RETRY_ENABLED_PROPERTY_NAME) == null) {
      configuration.setProperty(CLUSTER_ENV_CONFIG_TYPE_NAME, COMMAND_RETRY_ENABLED_PROPERTY_NAME, COMMAND_RETRY_ENABLED_DEFAULT);
      wasUpdated = true;
    }

    if (configuration.getPropertyValue(CLUSTER_ENV_CONFIG_TYPE_NAME, COMMANDS_TO_RETRY_PROPERTY_NAME) == null) {
      configuration.setProperty(CLUSTER_ENV_CONFIG_TYPE_NAME, COMMANDS_TO_RETRY_PROPERTY_NAME, COMMANDS_TO_RETRY_DEFAULT);
      wasUpdated = true;
    }

    if (configuration.getPropertyValue(CLUSTER_ENV_CONFIG_TYPE_NAME, COMMAND_RETRY_MAX_TIME_IN_SEC_PROPERTY_NAME) == null) {
      configuration.setProperty(CLUSTER_ENV_CONFIG_TYPE_NAME, COMMAND_RETRY_MAX_TIME_IN_SEC_PROPERTY_NAME, COMMAND_RETRY_MAX_TIME_IN_SEC_DEFAULT);
      wasUpdated = true;
    }

    if (wasUpdated) {
      configTypesUpdated.add(CLUSTER_ENV_CONFIG_TYPE_NAME);
    }
  }


  /**
   * Sets the read-only properties for stack features & tools, overriding
   * anything provided in the blueprint.
   *
   * @param configuration
   *          the configuration to update with values from the stack.
   * @param configTypesUpdated
   *          the list of configuration types updated (cluster-env will be added
   *          to this).
   * @throws ConfigurationTopologyException
   */
  protected void setStackToolsAndFeatures(Configuration configuration, Set<String> configTypesUpdated)
    throws ConfigurationTopologyException {
    ConfigHelper configHelper = clusterTopology.getAmbariContext().getConfigHelper();
    Stack stack = clusterTopology.getBlueprint().getStack();
    String stackName = stack.getName();
    String stackVersion = stack.getVersion();

    StackId stackId = new StackId(stackName, stackVersion);

    Set<String> properties = Sets.newHashSet(
      ConfigHelper.CLUSTER_ENV_STACK_NAME_PROPERTY,
      ConfigHelper.CLUSTER_ENV_STACK_ROOT_PROPERTY,
      ConfigHelper.CLUSTER_ENV_STACK_TOOLS_PROPERTY,
      ConfigHelper.CLUSTER_ENV_STACK_FEATURES_PROPERTY,
      ConfigHelper.CLUSTER_ENV_STACK_PACKAGES_PROPERTY);

    try {
      Map<String, Map<String, String>> defaultStackProperties = configHelper.getDefaultStackProperties(stackId);
      Map<String,String> clusterEnvDefaultProperties = defaultStackProperties.get(CLUSTER_ENV_CONFIG_TYPE_NAME);

      for( String property : properties ){
        if (clusterEnvDefaultProperties.containsKey(property)) {
          String newValue = clusterEnvDefaultProperties.get(property);
          String previous = configuration.setProperty(CLUSTER_ENV_CONFIG_TYPE_NAME, property, newValue);
          if (!Objects.equals(
            trimValue(previous, stack, CLUSTER_ENV_CONFIG_TYPE_NAME, property),
            trimValue(newValue, stack, CLUSTER_ENV_CONFIG_TYPE_NAME, property))) {
            // in case a property is updated make sure to include cluster-env as being updated
            configTypesUpdated.add(CLUSTER_ENV_CONFIG_TYPE_NAME);
          }
        }
      }
    } catch( AmbariException ambariException ){
      throw new ConfigurationTopologyException("Unable to retrieve the stack tools and features",
        ambariException);
    }
  }

  /**
   * Ensures that properties non-stack properties are present in {@code configuration}.
   */
  private static void injectDefaults(Configuration configuration, Set<String> configTypesUpdated, Collection<String> services) {
    setRetryConfiguration(configuration, configTypesUpdated);
    setupHDFSProxyUsers(configuration, configTypesUpdated, services);
  }

  private @Nullable String trimValue(@Nullable String value,
                                     @NotNull Stack stack,
                                     @NotNull String configType,
                                     @NotNull String propertyName) {
    if (null == value) {
      return null;
    }
    else {
      TrimmingStrategy trimmingStrategy =
        PropertyValueTrimmingStrategyDefiner.defineTrimmingStrategy(stack, propertyName, configType);
      return trimmingStrategy.trim(value);
    }
  }

  /**
   * Ensure that the specified property exists.
   * If not, set a default value.
   *
   * @param configuration  configuration being processed
   * @param type           config type
   * @param property       property name
   * @param defaultValue   default value
   */
  private static void ensureProperty(Configuration configuration, String type, String property, String defaultValue, Set<String> configTypesUpdated) {
    if (configuration.getPropertyValue(type, property) == null) {
      configuration.setProperty(type, property, defaultValue);
      configTypesUpdated.add(type);
    }
  }


  /**
   * Defines an interface for querying a filter to determine
   * if a given property should be included in an external
   * collection of properties.
   */
  private interface PropertyFilter {

    /**
     * Query to determine if a given property should be included in a collection of
     * properties.
     *
     * @param propertyName property name
     * @param propertyValue property value
     * @param configType config type that contains this property
     * @param topology cluster topology instance
     * @return true if the property should be included
     *         false if the property should not be included
     */
    boolean isPropertyIncluded(String propertyName, String propertyValue, String configType, ClusterTopology topology);
  }

  /**
   * A Filter that excludes properties if the property name matches
   * a pattern of "*PASSWORD" (case-insensitive).
   *
   */
  private static class PasswordPropertyFilter implements PropertyFilter {

    private static final Pattern PASSWORD_NAME_REGEX = Pattern.compile("\\S+(PASSWORD|SECRET)", Pattern.CASE_INSENSITIVE);

    /**
     * Query to determine if a given property should be included in a collection of
     * properties.
     *
     * This implementation uses a regular expression to determine if
     * a given property name ends with "PASSWORD", using a case-insensitive match.
     * This will be used to filter out Ranger passwords that are not considered "required"
     * passwords by the stack metadata. This could potentially also
     * be useful in filtering out properties that are added to
     * stacks, but not directly marked as the PASSWORD type, even if they
     * are indeed passwords.
     *
     *
     * @param propertyName property name
     * @param propertyValue property value
     * @param configType config type that contains this property
     * @param topology cluster topology instance
     *
     * @return true if the property should be included
     *         false if the property should not be included
     */
    @Override
    public boolean isPropertyIncluded(String propertyName, String propertyValue, String configType, ClusterTopology topology) {
      return !PASSWORD_NAME_REGEX.matcher(propertyName).matches();
    }
  }

  /**
   * A Filter that excludes properties if in stack a property is marked as password property or kerberos principal
   *
   */
  private static class StackPropertyTypeFilter implements PropertyFilter {

    /**
     * Query to determine if a given property should be included in a collection of
     * properties.
     *
     * This implementation filters property if in stack configuration is the property type is password or kerberos principal.
     *
     * @param propertyName property name
     * @param propertyValue property value
     * @param configType config type that contains this property
     * @param topology cluster topology instance
     *
     * @return true if the property should be included
     *         false if the property should not be included
     */
    @Override
    public boolean isPropertyIncluded(String propertyName, String propertyValue, String configType, ClusterTopology topology) {
      Stack stack = topology.getBlueprint().getStack();
      final String serviceName = stack.getServiceForConfigType(configType);
      return !(stack.isPasswordProperty(serviceName, configType, propertyName) ||
        stack.isKerberosPrincipalNameProperty(serviceName, configType, propertyName));
    }
  }

  /**
   * A Filter that excludes Kerberos auth_to_local rules properties.
   */
  private static class KerberosAuthToLocalRulesFilter implements PropertyFilter {

    /**
     * Query to determine if a given property should be included in a collection of
     * properties.
     *
     * This implementation filters Kerberos auth_to_local rules properties.
     *
     * @param propertyName property name
     * @param propertyValue property value
     * @param configType config type that contains this property
     * @param topology cluster topology instance
     *
     * @return true if the property should be included
     *         false if the property should not be included
     */
    Map<Long, Set<String>> authToLocalPerClusterMap = null;
    KerberosAuthToLocalRulesFilter (Map<Long, Set<String>> authToLocalPerClusterMap) {
      this.authToLocalPerClusterMap = authToLocalPerClusterMap;
    }
    @Override
    public boolean isPropertyIncluded(String propertyName, String propertyValue, String configType, ClusterTopology topology) {
      return (authToLocalPerClusterMap == null || authToLocalPerClusterMap.get(topology.getClusterId()) == null || !authToLocalPerClusterMap.get(topology.getClusterId()).contains(String.format("%s/%s", configType, propertyName)));
    }
  }

  /**
   * Simple filter implementation used to remove named properties from
   * a Blueprint export.  Some properties with hostname information set
   * by the UI do not have straightforward mappings to hosts, so these properties
   * cannot be exported via the default HOSTGROUP mechanism.
   */
  private static class SimplePropertyNameExportFilter implements PropertyFilter {

    private final String propertyName;

    private final String propertyConfigType;

    SimplePropertyNameExportFilter(String propertyName, String propertyConfigType) {
      this.propertyName = propertyName;
      this.propertyConfigType = propertyConfigType;
    }

    @Override
    public boolean isPropertyIncluded(String propertyName, String propertyValue, String configType, ClusterTopology topology) {
      return !(propertyConfigType.equals(configType) &&
        this.propertyName.equals(propertyName));
    }
  }


  /**
   * Filter implementation that determines if a property should be included in
   * a collection by inspecting the configuration dependencies included in the
   * stack definitions for a given property.
   *
   * The DependencyFilter is initialized with a given property that is listed
   * as a dependency of some properties in the stacks. If the dependency is found,
   * it must match a given condition (implemented in concrete subclasses) in
   * order to be included in a collection.
   */
  private static abstract class DependencyFilter implements PropertyFilter {

    private final String dependsOnPropertyName;

    private final String dependsOnConfigType;

    DependencyFilter(String dependsOnPropertyName, String dependsOnConfigType) {
      this.dependsOnPropertyName = dependsOnPropertyName;
      this.dependsOnConfigType = dependsOnConfigType;
    }


    /**
     * Inspects stack dependencies to determine if a given property
     * should be included in a collection.
     *
     * @param propertyName property name
     * @param propertyValue property value
     * @param configType config type that contains this property
     * @param topology cluster topology instance
     *
     * @return true if the property should be included
     *         false if the property should not be included
     */
    @Override
    public boolean isPropertyIncluded(String propertyName, String propertyValue, String configType, ClusterTopology topology) {
      Stack stack = topology.getBlueprint().getStack();
      Configuration configuration = topology.getConfiguration();

      final String serviceName = stack.getServiceForConfigType(configType);
      Map<String, Stack.ConfigProperty> typeProperties =
        stack.getConfigurationPropertiesWithMetadata(serviceName, configType);

      Stack.ConfigProperty configProperty = typeProperties.get(propertyName);
      if (configProperty != null) {
        Set<PropertyDependencyInfo> dependencyInfos = configProperty.getDependsOnProperties();
        if (dependencyInfos != null) {
          // iterate over the dependencies specified for this property in the stack
          for (PropertyDependencyInfo propertyDependencyInfo : dependencyInfos) {
            if (propertyDependencyInfo.getName().equals(dependsOnPropertyName) && (propertyDependencyInfo.getType().equals(dependsOnConfigType))) {
              // this property depends upon one of the registered dependency properties
              Map<String, Map<String, String>> clusterConfig = configuration.getFullProperties();
              Map<String, String> configByType = clusterConfig.get(dependsOnConfigType);
              return isConditionSatisfied(dependsOnPropertyName, configByType.get(dependsOnPropertyName), dependsOnConfigType);
            }
          }
        }
      }

      // always include properties by default, unless a defined
      // filter is found and the condition specified by the filter
      // is not satisfied
      return true;
    }

    /**
     * Abstract method used to determine if the value of a given dependency property
     * meets a given condition.
     *
     * @param propertyName name of property
     * @param propertyValue value of property
     * @param propertyType configuration type of contains this property
     * @return  true if the condition is satisfied for this property
     *          false if the condition is not satisfied for this property
     */
    public abstract boolean isConditionSatisfied(String propertyName, String propertyValue, String propertyType);

  }

  /**
   * DependencyFilter subclass that requires that the specified
   * dependency have a specific value in order for properties that
   * depend on it to be included in a collection.
   */
  private static class DependencyEqualsFilter extends DependencyFilter {

    private final String value;

    DependencyEqualsFilter(String dependsOnPropertyName, String dependsOnConfigType, String value) {
      super(dependsOnPropertyName, dependsOnConfigType);

      this.value = value;
    }

    /**
     *
     * @param propertyName name of property
     * @param propertyValue value of property
     * @param propertyType configuration type of contains this property
     * @return true if the property is equal to the expected value
     *         false if the property does not equal the expected value
     */
    @Override
    public boolean isConditionSatisfied(String propertyName, String propertyValue, String propertyType) {
      return value.equals(propertyValue);
    }
  }

  /**
   * DependencyFilter subclass that requires that the specified
   * dependency not have the specified value in order for properties that
   * depend on it to be included in a collection.
   */
  private static class DependencyNotEqualsFilter extends DependencyFilter {

    private final String value;

    DependencyNotEqualsFilter(String dependsOnPropertyName, String dependsOnConfigType, String value) {
      super(dependsOnPropertyName, dependsOnConfigType);

      this.value = value;
    }

    /**
     *
     * @param propertyName name of property
     * @param propertyValue value of property
     * @param propertyType configuration type of contains this property
     * @return true if the property is not equal to the expected value
     *         false if the property is equal to the expected value
     *
     */
    @Override
    public boolean isConditionSatisfied(String propertyName, String propertyValue, String propertyType) {
      return !value.equals(propertyValue);
    }
  }

  /**
   * Filter implementation that scans for HDFS NameNode properties that should be
   * removed/ignored when HDFS NameNode HA is enabled.
   */
  private static class HDFSNameNodeHAFilter implements PropertyFilter {

    /**
     * Set of HDFS Property names that are only valid in a non-HA scenario.
     * In an HA setup, the property names include the names of the nameservice and
     * namenode.
     */
    private final Set<String> setOfHDFSPropertyNamesNonHA =
      Collections.unmodifiableSet(new HashSet<>(Arrays.asList("dfs.namenode.http-address", "dfs.namenode.https-address", "dfs.namenode.rpc-address")));


    /**
     *
     * @param propertyName property name
     * @param propertyValue property value
     * @param configType config type that contains this property
     * @param topology cluster topology instance
     *
     * @return true if the property should be included
     *         false if the property should not be included
     */
    @Override
    public boolean isPropertyIncluded(String propertyName, String propertyValue, String configType, ClusterTopology topology) {
      if (topology.isNameNodeHAEnabled()) {
        if (setOfHDFSPropertyNamesNonHA.contains(propertyName)) {
          return false;
        }
      }

      return true;
    }
  }

  /**
   * Filter implementation filters out a property depending on property value.
   */
  private static class ConditionalPropertyFilter implements PropertyFilter {

    private final String propertyName;
    private final String propertyValue;
    private final String configType;

    public ConditionalPropertyFilter(String configType, String propertyName, String propertyValue) {
      this.propertyName = propertyName;
      this.propertyValue = propertyValue;
      this.configType = configType;
    }

    /**
     *
     * @param propertyName property name
     * @param propertyValue property value
     * @param configType config type that contains this property
     * @param topology cluster topology instance
     *
     * @return true if the property should be included
     *         false if the property should not be included
     */
    @Override
    public boolean isPropertyIncluded(String propertyName, String propertyValue, String configType, ClusterTopology topology) {
      if (configType.equals(this.configType) && propertyName.equals(this.propertyName) && propertyValue.equals(this
        .propertyValue)) {
        return false;
      }
      return true;
    }
  }

  /**
   * Filter implementation that scans for HAWQ HA properties that should be
   * removed/ignored when HAWQ HA is not enabled.
   */
  private static class HawqHAFilter implements PropertyFilter {

    /**
     * Set of HAWQ Property names that are only valid in a HA scenario.
     */
    private final Set<String> setOfHawqPropertyNamesNonHA =
      Collections.unmodifiableSet(new HashSet<>(Arrays.asList(HAWQ_SITE_HAWQ_STANDBY_ADDRESS_HOST)));


    /**
     *
     * @param propertyName property name
     * @param propertyValue property value
     * @param configType config type that contains this property
     * @param topology cluster topology instance
     *
     * @return true if the property should be included
     *         false if the property should not be included
     */
    @Override
    public boolean isPropertyIncluded(String propertyName, String propertyValue, String configType, ClusterTopology topology) {
      int matchingGroupCount = topology.getHostGroupsForComponent(HAWQSTANDBY).size();
      if (matchingGroupCount == 0) {
        if (setOfHawqPropertyNamesNonHA.contains(propertyName)) {
          return false;
        }
      }

      return true;
    }
  }


}