src/main/java/org/apache/sling/discovery/impl/Config.java - sling-org-apache-sling-discovery-impl - Git at Google

 /*
  * 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.sling.discovery.impl;

 import java.net.MalformedURLException;
 import java.net.URL;
 import java.util.LinkedList;
 import java.util.List;
 import java.util.Map;

 import org.apache.felix.scr.annotations.Activate;
 import org.apache.felix.scr.annotations.Component;
 import org.apache.felix.scr.annotations.Property;
 import org.apache.felix.scr.annotations.Service;
 import org.apache.sling.commons.osgi.PropertiesUtil;
 import org.apache.sling.discovery.base.connectors.BaseConfig;
 import org.apache.sling.discovery.commons.providers.spi.base.DiscoveryLiteConfig;
 import org.slf4j.Logger;
 import org.slf4j.LoggerFactory;

 /**
  * Configuration object used as a central config point for the discovery service
  * implementation
  * <p>
  * The properties are described below under.
  */
 @Component(metatype = true, label="%config.name", description="%config.description")
 @Service(value = { Config.class, BaseConfig.class, DiscoveryLiteConfig.class })
 public class Config implements BaseConfig, DiscoveryLiteConfig {

     private final Logger logger = LoggerFactory.getLogger(this.getClass());

     /** resource used to keep instance information such as last heartbeat, properties, incoming announcements **/
     private static final String CLUSTERINSTANCES_RESOURCE = "clusterInstances";

     /** resource used to store the sync tokens as part of a topology change **/
     private static final String SYNC_TOKEN_RESOURCE = "syncTokens";

     /** resource used to store the clusterNodeIds to slingIds map **/
     private static final String ID_MAP_RESOURCE = "idMap";

     /** resource used to keep the currently established view **/
     private static final String ESTABLISHED_VIEW_RESOURCE = "establishedView";

     /** resource used to keep the previously established view **/
     private static final String PREVIOUS_VIEW_RESOURCE = "previousView";

     /** resource used to keep ongoing votings **/
     private static final String ONGOING_VOTING_RESOURCE = "ongoingVotings";

     /** Configure the timeout (in seconds) after which an instance is considered dead/crashed. */
     public static final long DEFAULT_HEARTBEAT_TIMEOUT = 120;
     @Property(longValue=DEFAULT_HEARTBEAT_TIMEOUT)
     public static final String HEARTBEAT_TIMEOUT_KEY = "heartbeatTimeout";
     protected long heartbeatTimeout = DEFAULT_HEARTBEAT_TIMEOUT;

     /** Configure the interval (in seconds) according to which the heartbeats are exchanged in the topology. */
     public static final long DEFAULT_HEARTBEAT_INTERVAL = 30;
     @Property(longValue=DEFAULT_HEARTBEAT_INTERVAL)
     public static final String HEARTBEAT_INTERVAL_KEY = "heartbeatInterval";
     protected long heartbeatInterval = DEFAULT_HEARTBEAT_INTERVAL;

     /** Configure the time (in seconds) which must be passed at minimum between sending TOPOLOGY_CHANGING/_CHANGED (avoid flooding). */
     public static final int DEFAULT_MIN_EVENT_DELAY = 3;
     @Property(intValue=DEFAULT_MIN_EVENT_DELAY)
     public static final String MIN_EVENT_DELAY_KEY = "minEventDelay";
     protected int minEventDelay = DEFAULT_MIN_EVENT_DELAY;

     /** Configure the socket connect timeout for topology connectors. */
     public static final int DEFAULT_CONNECTION_TIMEOUT = 10;
     @Property(intValue=DEFAULT_CONNECTION_TIMEOUT)
     public static final String CONNECTION_TIMEOUT_KEY = "connectionTimeout";
     private int connectionTimeout = DEFAULT_CONNECTION_TIMEOUT;

     /** Configure the socket read timeout (SO_TIMEOUT) for topology connectors. */
     public static final int DEFAULT_SO_TIMEOUT = 10;
     @Property(intValue=DEFAULT_SO_TIMEOUT)
     public static final String SO_TIMEOUT_KEY = "soTimeout";
     private int soTimeout = DEFAULT_SO_TIMEOUT;

     /** Name of the repository descriptor to be taken into account for leader election:
         those instances have preference to become leader which have the corresponding descriptor value of 'false' */
     @Property
     public static final String LEADER_ELECTION_REPOSITORY_DESCRIPTOR_NAME_KEY = "leaderElectionRepositoryDescriptor";

     /**
      * Whether or not (default false) the leaderElectionRepositoryDescriptor should be inverted (if that one
      * is configured at all).
      */
     @Property(boolValue=false)
     public static final String INVERT_REPOSITORY_DESCRIPTOR_NAME_KEY = "invertRepositoryDescriptor";

     /** URLs where to join a topology, eg http://localhost:4502/libs/sling/topology/connector */
     @Property(cardinality=1024)
     public static final String TOPOLOGY_CONNECTOR_URLS_KEY = "topologyConnectorUrls";
     private URL[] topologyConnectorUrls = {null};

     /** list of ips and/or hostnames which are allowed to connect to /libs/sling/topology/connector */
     private static final String[] DEFAULT_TOPOLOGY_CONNECTOR_WHITELIST = {"localhost","127.0.0.1"};
     @Property(value={"localhost","127.0.0.1"})
     public static final String TOPOLOGY_CONNECTOR_WHITELIST_KEY = "topologyConnectorWhitelist";
     private String[] topologyConnectorWhitelist = DEFAULT_TOPOLOGY_CONNECTOR_WHITELIST;

     /** Path of resource where to keep discovery information, e.g /var/discovery/impl/ */
     private static final String DEFAULT_DISCOVERY_RESOURCE_PATH = "/var/discovery/impl/";
     @Property(value=DEFAULT_DISCOVERY_RESOURCE_PATH, propertyPrivate=true)
     public static final String DISCOVERY_RESOURCE_PATH_KEY = "discoveryResourcePath";
     private String discoveryResourcePath = DEFAULT_DISCOVERY_RESOURCE_PATH;

     /**
      * If set to true, local-loops of topology connectors are automatically stopped when detected so.
      */
     @Property(boolValue=false)
     private static final String AUTO_STOP_LOCAL_LOOP_ENABLED = "autoStopLocalLoopEnabled";

     /**
      * If set to true, request body will be gzipped - only works if counter-part accepts gzip-requests!
      */
     @Property(boolValue=false)
     private static final String GZIP_CONNECTOR_REQUESTS_ENABLED = "gzipConnectorRequestsEnabled";

     /**
      * If set to true, hmac is enabled and the white list is disabled.
      */
     @Property(boolValue=false)
     private static final String HMAC_ENABLED = "hmacEnabled";

     /**
      * If set to true, and the whitelist is disabled, messages will be encrypted.
      */
     @Property(boolValue=false)
     private static final String ENCRYPTION_ENABLED = "enableEncryption";

     /**
      * The value fo the shared key, shared amongst all instances in the same cluster.
      */
     @Property
     private static final String SHARED_KEY = "sharedKey";

     /**
      * The default lifetime of a HMAC shared key in ms. (4h)
      */
     private static final long DEFAULT_SHARED_KEY_INTERVAL = 3600*1000*4;

     @Property(longValue=DEFAULT_SHARED_KEY_INTERVAL)
     private static final String SHARED_KEY_INTERVAL = "hmacSharedKeyTTL";

     /**
      * The property for defining the backoff factor for standby (loop) connectors
      */
     @Property
     private static final String BACKOFF_STANDBY_FACTOR = "backoffStandbyFactor";
     private static final int DEFAULT_BACKOFF_STANDBY_FACTOR = 5;

     /**
      * The property for defining the maximum backoff factor for stable connectors
      */
     @Property
     private static final String BACKOFF_STABLE_FACTOR = "backoffStableFactor";
     private static final int DEFAULT_BACKOFF_STABLE_FACTOR = 5;

     /**
      * when set to true and the syncTokenService (of discovery.commons) is available,
      * then it is used
      */
     @Property(boolValue=true)
     private static final String USE_SYNC_TOKEN_SERVICE_ENABLED = "useSyncTokenService";

     private String leaderElectionRepositoryDescriptor ;

     private boolean invertRepositoryDescriptor = false; /* default: false */

     /** True when auto-stop of a local-loop is enabled. Default is false. **/
     private boolean autoStopLocalLoopEnabled;

     /**
      * True when the hmac is enabled and signing is disabled.
      */
     private boolean hmacEnabled;

     /**
      * the shared key.
      */
     private String sharedKey;

     /**
      * The key interval.
      */
     private long keyInterval;

     /**
      * true when encryption is enabled.
      */
     private boolean encryptionEnabled;

     /**
      * true when topology connector requests should be gzipped
      */
     private boolean gzipConnectorRequestsEnabled;

     /** the backoff factor to be used for standby (loop) connectors **/
     private int backoffStandbyFactor = DEFAULT_BACKOFF_STANDBY_FACTOR;

     /** the maximum backoff factor to be used for stable connectors **/
     private int backoffStableFactor = DEFAULT_BACKOFF_STABLE_FACTOR;

     /**
      * when set to true and the syncTokenService (of discovery.commons) is available,
      * then it is used.
      */
     private boolean useSyncTokenService = true;

     @Activate
     protected void activate(final Map<String, Object> properties) {
 		logger.debug("activate: config activated.");
         configure(properties);
     }

     protected void configure(final Map<String, Object> properties) {
         this.heartbeatTimeout = PropertiesUtil.toLong(
                 properties.get(HEARTBEAT_TIMEOUT_KEY),
                 DEFAULT_HEARTBEAT_TIMEOUT);
         logger.debug("configure: heartbeatTimeout='{}'", this.heartbeatTimeout);

         this.heartbeatInterval = PropertiesUtil.toLong(
                 properties.get(HEARTBEAT_INTERVAL_KEY),
                 DEFAULT_HEARTBEAT_INTERVAL);
         logger.debug("configure: heartbeatInterval='{}'",
                 this.heartbeatInterval);

         this.minEventDelay = PropertiesUtil.toInteger(
                 properties.get(MIN_EVENT_DELAY_KEY),
                 DEFAULT_MIN_EVENT_DELAY);
         logger.debug("configure: minEventDelay='{}'",
                 this.minEventDelay);

         this.connectionTimeout = PropertiesUtil.toInteger(
                 properties.get(CONNECTION_TIMEOUT_KEY),
                 DEFAULT_CONNECTION_TIMEOUT);
         logger.debug("configure: connectionTimeout='{}'",
                 this.connectionTimeout);

         this.soTimeout = PropertiesUtil.toInteger(
                 properties.get(SO_TIMEOUT_KEY),
                 DEFAULT_SO_TIMEOUT);
         logger.debug("configure: soTimeout='{}'",
                 this.soTimeout);


         String[] topologyConnectorUrlsStr = PropertiesUtil.toStringArray(
                 properties.get(TOPOLOGY_CONNECTOR_URLS_KEY), null);
         if (topologyConnectorUrlsStr!=null && topologyConnectorUrlsStr.length > 0) {
             List<URL> urls = new LinkedList<URL>();
             for (int i = 0; i < topologyConnectorUrlsStr.length; i++) {
                 String anUrlStr = topologyConnectorUrlsStr[i];
                 try {
                 	if (anUrlStr!=null && anUrlStr.length()>0) {
 	                    URL url = new URL(anUrlStr);
 	                    logger.debug("configure: a topologyConnectorbUrl='{}'",
 	                            url);
 	                    urls.add(url);
                 	}
                 } catch (MalformedURLException e) {
                     logger.error("configure: could not set a topologyConnectorUrl: " + e,
                             e);
                 }
             }
             if (urls.size()>0) {
                 this.topologyConnectorUrls = urls.toArray(new URL[urls.size()]);
                 logger.debug("configure: number of topologyConnectorUrls='{}''",
                         urls.size());
             } else {
                 this.topologyConnectorUrls = null;
                 logger.debug("configure: no (valid) topologyConnectorUrls configured");
             }
         } else {
             this.topologyConnectorUrls = null;
             logger.debug("configure: no (valid) topologyConnectorUrls configured");
         }
         this.topologyConnectorWhitelist = PropertiesUtil.toStringArray(
                 properties.get(TOPOLOGY_CONNECTOR_WHITELIST_KEY),
                 DEFAULT_TOPOLOGY_CONNECTOR_WHITELIST);
         logger.debug("configure: topologyConnectorWhitelist='{}'",
                 this.topologyConnectorWhitelist);

         this.discoveryResourcePath = PropertiesUtil.toString(
                 properties.get(DISCOVERY_RESOURCE_PATH_KEY),
                 "");
         while(this.discoveryResourcePath.endsWith("/")) {
             this.discoveryResourcePath = this.discoveryResourcePath.substring(0,
                     this.discoveryResourcePath.length()-1);
         }
         this.discoveryResourcePath = this.discoveryResourcePath + "/";
         if (this.discoveryResourcePath==null || this.discoveryResourcePath.length()<=1) {
             // if the path is empty, or /, then use the default
             this.discoveryResourcePath = DEFAULT_DISCOVERY_RESOURCE_PATH;
         }
         logger.debug("configure: discoveryResourcePath='{}'",
                 this.discoveryResourcePath);

         this.leaderElectionRepositoryDescriptor = PropertiesUtil.toString(
                 properties.get(LEADER_ELECTION_REPOSITORY_DESCRIPTOR_NAME_KEY),
                 null);
         logger.debug("configure: leaderElectionRepositoryDescriptor='{}'",
                 this.leaderElectionRepositoryDescriptor);

         this.invertRepositoryDescriptor = PropertiesUtil.toBoolean(
                 properties.get(INVERT_REPOSITORY_DESCRIPTOR_NAME_KEY),
                 false /* default: false*/);
         logger.debug("configure: invertRepositoryDescriptor='{}'",
                 this.invertRepositoryDescriptor);

         autoStopLocalLoopEnabled = PropertiesUtil.toBoolean(properties.get(AUTO_STOP_LOCAL_LOOP_ENABLED), false);
         gzipConnectorRequestsEnabled = PropertiesUtil.toBoolean(properties.get(GZIP_CONNECTOR_REQUESTS_ENABLED), false);

         hmacEnabled = PropertiesUtil.toBoolean(properties.get(HMAC_ENABLED), true);
         encryptionEnabled = PropertiesUtil.toBoolean(properties.get(ENCRYPTION_ENABLED), false);
         sharedKey = PropertiesUtil.toString(properties.get(SHARED_KEY), null);
         keyInterval = PropertiesUtil.toLong(SHARED_KEY_INTERVAL, DEFAULT_SHARED_KEY_INTERVAL);

         backoffStandbyFactor = PropertiesUtil.toInteger(properties.get(BACKOFF_STANDBY_FACTOR),
                 DEFAULT_BACKOFF_STANDBY_FACTOR);
         backoffStableFactor = PropertiesUtil.toInteger(properties.get(BACKOFF_STABLE_FACTOR),
                 DEFAULT_BACKOFF_STABLE_FACTOR);

         useSyncTokenService = PropertiesUtil.toBoolean(properties.get(USE_SYNC_TOKEN_SERVICE_ENABLED), true);
     }

     /**
      * Returns the timeout (in seconds) after which an instance or voting is considered invalid/timed out
      * @return the timeout (in seconds) after which an instance or voting is considered invalid/timed out
      */
     public long getHeartbeatTimeout() {
         return heartbeatTimeout;
     }

     /**
      * Returns the timeout (in milliseconds) after which an instance or voting is considered invalid/timed out
      * @return the timeout (in milliseconds) after which an instance or voting is considered invalid/timed out
      */
     public long getHeartbeatTimeoutMillis() {
         return getHeartbeatTimeout() * 1000;
     }

     /**
      * Returns the socket connect() timeout used by the topology connector, 0 disables the timeout
      * @return the socket connect() timeout used by the topology connector, 0 disables the timeout
      */
     public int getSocketConnectTimeout() {
         return connectionTimeout;
     }

     /**
      * Returns the socket read timeout (SO_TIMEOUT) used by the topology connector, 0 disables the timeout
      * @return the socket read timeout (SO_TIMEOUT) used by the topology connector, 0 disables the timeout
      */
     public int getSoTimeout() {
         return soTimeout;
     }

     /**
      * Returns the interval (in seconds) in which heartbeats are sent
      * @return the interval (in seconds) in which heartbeats are sent
      */
     public long getHeartbeatInterval() {
         return heartbeatInterval;
     }

     /**
      * Returns the minimum time (in seconds) between sending TOPOLOGY_CHANGING/_CHANGED events - to avoid flooding
      * @return the minimum time (in seconds) between sending TOPOLOGY_CHANGING/_CHANGED events - to avoid flooding
      */
     public int getMinEventDelay() {
         return minEventDelay;
     }

     /**
      * Returns the URLs to which to open a topology connector - or null/empty if no topology connector
      * is configured (default is null)
      * @return the URLs to which to open a topology connector - or null/empty if no topology connector
      * is configured
      */
     public URL[] getTopologyConnectorURLs() {
         return topologyConnectorUrls;
     }

     /**
      * Returns a comma separated list of hostnames and/or ip addresses which are allowed as
      * remote hosts to open connections to the topology connector servlet
      * @return a comma separated list of hostnames and/or ip addresses which are allowed as
      * remote hosts to open connections to the topology connector servlet
      */
     public String[] getTopologyConnectorWhitelist() {
         return topologyConnectorWhitelist;
     }

     public String getDiscoveryResourcePath() {
         return discoveryResourcePath;
     }

     /**
      * Returns the resource path where cluster instance informations are stored.
      * @return the resource path where cluster instance informations are stored
      */
     public String getClusterInstancesPath() {
         return getDiscoveryResourcePath() + CLUSTERINSTANCES_RESOURCE;
     }

     /**
      * Returns the resource path where the established view is stored.
      * @return the resource path where the established view is stored
      */
     public String getEstablishedViewPath() {
         return getDiscoveryResourcePath() + ESTABLISHED_VIEW_RESOURCE;
     }

     /**
      * Returns the resource path where ongoing votings are stored.
      * @return the resource path where ongoing votings are stored
      */
     public String getOngoingVotingsPath() {
         return getDiscoveryResourcePath() + ONGOING_VOTING_RESOURCE;
     }

     /**
      * Returns the resource path where the previous view is stored.
      * @return the resource path where the previous view is stored
      */
     public String getPreviousViewPath() {
         return getDiscoveryResourcePath() + PREVIOUS_VIEW_RESOURCE;
     }

     /**
      * Returns the repository descriptor key which is to be included in the
      * cluster leader election - or null.
      * <p>
      * When set, the value (treated as a boolean) of the repository descriptor
      * is prepended to the leader election id.
      * @return the repository descriptor key which is to be included in the
      * cluster leader election - or null
      */
     public String getLeaderElectionRepositoryDescriptor() {
         return leaderElectionRepositoryDescriptor;
     }

     /**
      * Returns true when the value of the repository descriptor identified
      * via the property 'leaderElectionRepositoryDescriptor' should be
      * inverted - only applies when 'leaderElectionRepositoryDescriptor'
      * is configured of course.
      * @return true when property resulting from 'leaderElectionRepositoryDescriptor'
      * should be inverted, false if it should remain unchanged.
      */
     public boolean shouldInvertRepositoryDescriptor() {
         return invertRepositoryDescriptor;
     }

     /**
      * @return true if hmac is enabled.
      */
     public boolean isHmacEnabled() {
         return hmacEnabled;
     }

     /**
      * @return the shared key
      */
     public String getSharedKey() {
         return sharedKey;
     }

     /**
      * @return the interval of the shared key for hmac.
      */
     public long getKeyInterval() {
         return keyInterval;
     }

     /**
      * @return true if encryption is enabled.
      */
     public boolean isEncryptionEnabled() {
         return encryptionEnabled;
     }

     /**
      * @return true if requests on the topology connector should be gzipped
      * (which only works if the server accepts that.. ie discovery.impl 1.0.4+)
      */
     public boolean isGzipConnectorRequestsEnabled() {
         return gzipConnectorRequestsEnabled;
     }

     /**
      * @return true if the auto-stopping of local-loop topology connectors is enabled.
      */
     public boolean isAutoStopLocalLoopEnabled() {
         return autoStopLocalLoopEnabled;
     }

     /**
      * Returns the backoff factor to be used for standby (loop) connectors
      * @return the backoff factor to be used for standby (loop) connectors
      */
     public int getBackoffStandbyFactor() {
         return backoffStandbyFactor;
     }

     /**
      * Returns the (maximum) backoff factor to be used for stable connectors
      * @return the (maximum) backoff factor to be used for stable connectors
      */
     public int getBackoffStableFactor() {
         return backoffStableFactor;
     }

     /**
      * Returns the backoff interval for standby (loop) connectors in seconds
      * @return the backoff interval for standby (loop) connectors in seconds
      */
     public long getBackoffStandbyInterval() {
         final int factor = getBackoffStandbyFactor();
         if (factor<=1) {
             return -1;
         } else {
             return factor * getHeartbeatInterval();
         }
     }

     @Override
     public long getConnectorPingInterval() {
         return getHeartbeatInterval();
     }

     @Override
     public long getConnectorPingTimeout() {
         return getHeartbeatTimeout();
     }

     @Override
     public String getSyncTokenPath() {
         return getDiscoveryResourcePath() + SYNC_TOKEN_RESOURCE;
     }

     @Override
     public String getIdMapPath() {
         return getDiscoveryResourcePath() + ID_MAP_RESOURCE;
     }

     @Override
     public long getClusterSyncServiceTimeoutMillis() {
         return -1;
     }

     @Override
     public long getClusterSyncServiceIntervalMillis() {
         return 1000;
     }

     public boolean useSyncTokenService() {
         return useSyncTokenService;
     }

 }
	/*
	* 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.sling.discovery.impl;

	import java.net.MalformedURLException;
	import java.net.URL;
	import java.util.LinkedList;
	import java.util.List;
	import java.util.Map;

	import org.apache.felix.scr.annotations.Activate;
	import org.apache.felix.scr.annotations.Component;
	import org.apache.felix.scr.annotations.Property;
	import org.apache.felix.scr.annotations.Service;
	import org.apache.sling.commons.osgi.PropertiesUtil;
	import org.apache.sling.discovery.base.connectors.BaseConfig;
	import org.apache.sling.discovery.commons.providers.spi.base.DiscoveryLiteConfig;
	import org.slf4j.Logger;
	import org.slf4j.LoggerFactory;

	/**
	* Configuration object used as a central config point for the discovery service
	* implementation
	* <p>
	* The properties are described below under.
	*/
	@Component(metatype = true, label="%config.name", description="%config.description")
	@Service(value = { Config.class, BaseConfig.class, DiscoveryLiteConfig.class })
	public class Config implements BaseConfig, DiscoveryLiteConfig {

	private final Logger logger = LoggerFactory.getLogger(this.getClass());

	/ resource used to keep instance information such as last heartbeat, properties, incoming announcements /
	private static final String CLUSTERINSTANCES_RESOURCE = "clusterInstances";

	/ resource used to store the sync tokens as part of a topology change /
	private static final String SYNC_TOKEN_RESOURCE = "syncTokens";

	/ resource used to store the clusterNodeIds to slingIds map /
	private static final String ID_MAP_RESOURCE = "idMap";

	/ resource used to keep the currently established view /
	private static final String ESTABLISHED_VIEW_RESOURCE = "establishedView";

	/ resource used to keep the previously established view /
	private static final String PREVIOUS_VIEW_RESOURCE = "previousView";

	/ resource used to keep ongoing votings /
	private static final String ONGOING_VOTING_RESOURCE = "ongoingVotings";

	/** Configure the timeout (in seconds) after which an instance is considered dead/crashed. */
	public static final long DEFAULT_HEARTBEAT_TIMEOUT = 120;
	@Property(longValue=DEFAULT_HEARTBEAT_TIMEOUT)
	public static final String HEARTBEAT_TIMEOUT_KEY = "heartbeatTimeout";
	protected long heartbeatTimeout = DEFAULT_HEARTBEAT_TIMEOUT;

	/** Configure the interval (in seconds) according to which the heartbeats are exchanged in the topology. */
	public static final long DEFAULT_HEARTBEAT_INTERVAL = 30;
	@Property(longValue=DEFAULT_HEARTBEAT_INTERVAL)
	public static final String HEARTBEAT_INTERVAL_KEY = "heartbeatInterval";
	protected long heartbeatInterval = DEFAULT_HEARTBEAT_INTERVAL;

	/** Configure the time (in seconds) which must be passed at minimum between sending TOPOLOGY_CHANGING/_CHANGED (avoid flooding). */
	public static final int DEFAULT_MIN_EVENT_DELAY = 3;
	@Property(intValue=DEFAULT_MIN_EVENT_DELAY)
	public static final String MIN_EVENT_DELAY_KEY = "minEventDelay";
	protected int minEventDelay = DEFAULT_MIN_EVENT_DELAY;

	/** Configure the socket connect timeout for topology connectors. */
	public static final int DEFAULT_CONNECTION_TIMEOUT = 10;
	@Property(intValue=DEFAULT_CONNECTION_TIMEOUT)
	public static final String CONNECTION_TIMEOUT_KEY = "connectionTimeout";
	private int connectionTimeout = DEFAULT_CONNECTION_TIMEOUT;

	/** Configure the socket read timeout (SO_TIMEOUT) for topology connectors. */
	public static final int DEFAULT_SO_TIMEOUT = 10;
	@Property(intValue=DEFAULT_SO_TIMEOUT)
	public static final String SO_TIMEOUT_KEY = "soTimeout";
	private int soTimeout = DEFAULT_SO_TIMEOUT;

	/** Name of the repository descriptor to be taken into account for leader election:
	those instances have preference to become leader which have the corresponding descriptor value of 'false' */
	@Property
	public static final String LEADER_ELECTION_REPOSITORY_DESCRIPTOR_NAME_KEY = "leaderElectionRepositoryDescriptor";

	/**
	* Whether or not (default false) the leaderElectionRepositoryDescriptor should be inverted (if that one
	* is configured at all).
	*/
	@Property(boolValue=false)
	public static final String INVERT_REPOSITORY_DESCRIPTOR_NAME_KEY = "invertRepositoryDescriptor";

	/** URLs where to join a topology, eg http://localhost:4502/libs/sling/topology/connector */
	@Property(cardinality=1024)
	public static final String TOPOLOGY_CONNECTOR_URLS_KEY = "topologyConnectorUrls";
	private URL[] topologyConnectorUrls = {null};

	/** list of ips and/or hostnames which are allowed to connect to /libs/sling/topology/connector */
	private static final String[] DEFAULT_TOPOLOGY_CONNECTOR_WHITELIST = {"localhost","127.0.0.1"};
	@Property(value={"localhost","127.0.0.1"})
	public static final String TOPOLOGY_CONNECTOR_WHITELIST_KEY = "topologyConnectorWhitelist";
	private String[] topologyConnectorWhitelist = DEFAULT_TOPOLOGY_CONNECTOR_WHITELIST;

	/** Path of resource where to keep discovery information, e.g /var/discovery/impl/ */
	private static final String DEFAULT_DISCOVERY_RESOURCE_PATH = "/var/discovery/impl/";
	@Property(value=DEFAULT_DISCOVERY_RESOURCE_PATH, propertyPrivate=true)
	public static final String DISCOVERY_RESOURCE_PATH_KEY = "discoveryResourcePath";
	private String discoveryResourcePath = DEFAULT_DISCOVERY_RESOURCE_PATH;

	/**
	* If set to true, local-loops of topology connectors are automatically stopped when detected so.
	*/
	@Property(boolValue=false)
	private static final String AUTO_STOP_LOCAL_LOOP_ENABLED = "autoStopLocalLoopEnabled";

	/**
	* If set to true, request body will be gzipped - only works if counter-part accepts gzip-requests!
	*/
	@Property(boolValue=false)
	private static final String GZIP_CONNECTOR_REQUESTS_ENABLED = "gzipConnectorRequestsEnabled";

	/**
	* If set to true, hmac is enabled and the white list is disabled.
	*/
	@Property(boolValue=false)
	private static final String HMAC_ENABLED = "hmacEnabled";

	/**
	* If set to true, and the whitelist is disabled, messages will be encrypted.
	*/
	@Property(boolValue=false)
	private static final String ENCRYPTION_ENABLED = "enableEncryption";

	/**
	* The value fo the shared key, shared amongst all instances in the same cluster.
	*/
	@Property
	private static final String SHARED_KEY = "sharedKey";

	/**
	* The default lifetime of a HMAC shared key in ms. (4h)
	*/
	private static final long DEFAULT_SHARED_KEY_INTERVAL = 360010004;

	@Property(longValue=DEFAULT_SHARED_KEY_INTERVAL)
	private static final String SHARED_KEY_INTERVAL = "hmacSharedKeyTTL";

	/**
	* The property for defining the backoff factor for standby (loop) connectors
	*/
	@Property
	private static final String BACKOFF_STANDBY_FACTOR = "backoffStandbyFactor";
	private static final int DEFAULT_BACKOFF_STANDBY_FACTOR = 5;

	/**
	* The property for defining the maximum backoff factor for stable connectors
	*/
	@Property
	private static final String BACKOFF_STABLE_FACTOR = "backoffStableFactor";
	private static final int DEFAULT_BACKOFF_STABLE_FACTOR = 5;

	/**
	* when set to true and the syncTokenService (of discovery.commons) is available,
	* then it is used
	*/
	@Property(boolValue=true)
	private static final String USE_SYNC_TOKEN_SERVICE_ENABLED = "useSyncTokenService";

	private String leaderElectionRepositoryDescriptor ;

	private boolean invertRepositoryDescriptor = false; /* default: false */

	/ True when auto-stop of a local-loop is enabled. Default is false. /
	private boolean autoStopLocalLoopEnabled;

	/**
	* True when the hmac is enabled and signing is disabled.
	*/
	private boolean hmacEnabled;

	/**
	* the shared key.
	*/
	private String sharedKey;

	/**
	* The key interval.
	*/
	private long keyInterval;

	/**
	* true when encryption is enabled.
	*/
	private boolean encryptionEnabled;

	/**
	* true when topology connector requests should be gzipped
	*/
	private boolean gzipConnectorRequestsEnabled;

	/ the backoff factor to be used for standby (loop) connectors /
	private int backoffStandbyFactor = DEFAULT_BACKOFF_STANDBY_FACTOR;

	/ the maximum backoff factor to be used for stable connectors /
	private int backoffStableFactor = DEFAULT_BACKOFF_STABLE_FACTOR;

	/**
	* when set to true and the syncTokenService (of discovery.commons) is available,
	* then it is used.
	*/
	private boolean useSyncTokenService = true;

	@Activate
	protected void activate(final Map<String, Object> properties) {
	logger.debug("activate: config activated.");
	configure(properties);
	}

	protected void configure(final Map<String, Object> properties) {
	this.heartbeatTimeout = PropertiesUtil.toLong(
	properties.get(HEARTBEAT_TIMEOUT_KEY),
	DEFAULT_HEARTBEAT_TIMEOUT);
	logger.debug("configure: heartbeatTimeout='{}'", this.heartbeatTimeout);

	this.heartbeatInterval = PropertiesUtil.toLong(
	properties.get(HEARTBEAT_INTERVAL_KEY),
	DEFAULT_HEARTBEAT_INTERVAL);
	logger.debug("configure: heartbeatInterval='{}'",
	this.heartbeatInterval);

	this.minEventDelay = PropertiesUtil.toInteger(
	properties.get(MIN_EVENT_DELAY_KEY),
	DEFAULT_MIN_EVENT_DELAY);
	logger.debug("configure: minEventDelay='{}'",
	this.minEventDelay);

	this.connectionTimeout = PropertiesUtil.toInteger(
	properties.get(CONNECTION_TIMEOUT_KEY),
	DEFAULT_CONNECTION_TIMEOUT);
	logger.debug("configure: connectionTimeout='{}'",
	this.connectionTimeout);

	this.soTimeout = PropertiesUtil.toInteger(
	properties.get(SO_TIMEOUT_KEY),
	DEFAULT_SO_TIMEOUT);
	logger.debug("configure: soTimeout='{}'",
	this.soTimeout);


	String[] topologyConnectorUrlsStr = PropertiesUtil.toStringArray(
	properties.get(TOPOLOGY_CONNECTOR_URLS_KEY), null);
	if (topologyConnectorUrlsStr!=null && topologyConnectorUrlsStr.length > 0) {
	List<URL> urls = new LinkedList<URL>();
	for (int i = 0; i < topologyConnectorUrlsStr.length; i++) {
	String anUrlStr = topologyConnectorUrlsStr[i];
	try {
	if (anUrlStr!=null && anUrlStr.length()>0) {
	URL url = new URL(anUrlStr);
	logger.debug("configure: a topologyConnectorbUrl='{}'",
	url);
	urls.add(url);
	}
	} catch (MalformedURLException e) {
	logger.error("configure: could not set a topologyConnectorUrl: " + e,
	e);
	}
	}
	if (urls.size()>0) {
	this.topologyConnectorUrls = urls.toArray(new URL[urls.size()]);
	logger.debug("configure: number of topologyConnectorUrls='{}''",
	urls.size());
	} else {
	this.topologyConnectorUrls = null;
	logger.debug("configure: no (valid) topologyConnectorUrls configured");
	}
	} else {
	this.topologyConnectorUrls = null;
	logger.debug("configure: no (valid) topologyConnectorUrls configured");
	}
	this.topologyConnectorWhitelist = PropertiesUtil.toStringArray(
	properties.get(TOPOLOGY_CONNECTOR_WHITELIST_KEY),
	DEFAULT_TOPOLOGY_CONNECTOR_WHITELIST);
	logger.debug("configure: topologyConnectorWhitelist='{}'",
	this.topologyConnectorWhitelist);

	this.discoveryResourcePath = PropertiesUtil.toString(
	properties.get(DISCOVERY_RESOURCE_PATH_KEY),
	"");
	while(this.discoveryResourcePath.endsWith("/")) {
	this.discoveryResourcePath = this.discoveryResourcePath.substring(0,
	this.discoveryResourcePath.length()-1);
	}
	this.discoveryResourcePath = this.discoveryResourcePath + "/";
	if (this.discoveryResourcePath==null \|\| this.discoveryResourcePath.length()<=1) {
	// if the path is empty, or /, then use the default
	this.discoveryResourcePath = DEFAULT_DISCOVERY_RESOURCE_PATH;
	}
	logger.debug("configure: discoveryResourcePath='{}'",
	this.discoveryResourcePath);

	this.leaderElectionRepositoryDescriptor = PropertiesUtil.toString(
	properties.get(LEADER_ELECTION_REPOSITORY_DESCRIPTOR_NAME_KEY),
	null);
	logger.debug("configure: leaderElectionRepositoryDescriptor='{}'",
	this.leaderElectionRepositoryDescriptor);

	this.invertRepositoryDescriptor = PropertiesUtil.toBoolean(
	properties.get(INVERT_REPOSITORY_DESCRIPTOR_NAME_KEY),
	false /* default: false*/);
	logger.debug("configure: invertRepositoryDescriptor='{}'",
	this.invertRepositoryDescriptor);

	autoStopLocalLoopEnabled = PropertiesUtil.toBoolean(properties.get(AUTO_STOP_LOCAL_LOOP_ENABLED), false);
	gzipConnectorRequestsEnabled = PropertiesUtil.toBoolean(properties.get(GZIP_CONNECTOR_REQUESTS_ENABLED), false);

	hmacEnabled = PropertiesUtil.toBoolean(properties.get(HMAC_ENABLED), true);
	encryptionEnabled = PropertiesUtil.toBoolean(properties.get(ENCRYPTION_ENABLED), false);
	sharedKey = PropertiesUtil.toString(properties.get(SHARED_KEY), null);
	keyInterval = PropertiesUtil.toLong(SHARED_KEY_INTERVAL, DEFAULT_SHARED_KEY_INTERVAL);

	backoffStandbyFactor = PropertiesUtil.toInteger(properties.get(BACKOFF_STANDBY_FACTOR),
	DEFAULT_BACKOFF_STANDBY_FACTOR);
	backoffStableFactor = PropertiesUtil.toInteger(properties.get(BACKOFF_STABLE_FACTOR),
	DEFAULT_BACKOFF_STABLE_FACTOR);

	useSyncTokenService = PropertiesUtil.toBoolean(properties.get(USE_SYNC_TOKEN_SERVICE_ENABLED), true);
	}

	/**
	* Returns the timeout (in seconds) after which an instance or voting is considered invalid/timed out
	* @return the timeout (in seconds) after which an instance or voting is considered invalid/timed out
	*/
	public long getHeartbeatTimeout() {
	return heartbeatTimeout;
	}

	/**
	* Returns the timeout (in milliseconds) after which an instance or voting is considered invalid/timed out
	* @return the timeout (in milliseconds) after which an instance or voting is considered invalid/timed out
	*/
	public long getHeartbeatTimeoutMillis() {
	return getHeartbeatTimeout() * 1000;
	}

	/**
	* Returns the socket connect() timeout used by the topology connector, 0 disables the timeout
	* @return the socket connect() timeout used by the topology connector, 0 disables the timeout
	*/
	public int getSocketConnectTimeout() {
	return connectionTimeout;
	}

	/**
	* Returns the socket read timeout (SO_TIMEOUT) used by the topology connector, 0 disables the timeout
	* @return the socket read timeout (SO_TIMEOUT) used by the topology connector, 0 disables the timeout
	*/
	public int getSoTimeout() {
	return soTimeout;
	}

	/**
	* Returns the interval (in seconds) in which heartbeats are sent
	* @return the interval (in seconds) in which heartbeats are sent
	*/
	public long getHeartbeatInterval() {
	return heartbeatInterval;
	}

	/**
	* Returns the minimum time (in seconds) between sending TOPOLOGY_CHANGING/_CHANGED events - to avoid flooding
	* @return the minimum time (in seconds) between sending TOPOLOGY_CHANGING/_CHANGED events - to avoid flooding
	*/
	public int getMinEventDelay() {
	return minEventDelay;
	}

	/**
	* Returns the URLs to which to open a topology connector - or null/empty if no topology connector
	* is configured (default is null)
	* @return the URLs to which to open a topology connector - or null/empty if no topology connector
	* is configured
	*/
	public URL[] getTopologyConnectorURLs() {
	return topologyConnectorUrls;
	}

	/**
	* Returns a comma separated list of hostnames and/or ip addresses which are allowed as
	* remote hosts to open connections to the topology connector servlet
	* @return a comma separated list of hostnames and/or ip addresses which are allowed as
	* remote hosts to open connections to the topology connector servlet
	*/
	public String[] getTopologyConnectorWhitelist() {
	return topologyConnectorWhitelist;
	}

	public String getDiscoveryResourcePath() {
	return discoveryResourcePath;
	}

	/**
	* Returns the resource path where cluster instance informations are stored.
	* @return the resource path where cluster instance informations are stored
	*/
	public String getClusterInstancesPath() {
	return getDiscoveryResourcePath() + CLUSTERINSTANCES_RESOURCE;
	}

	/**
	* Returns the resource path where the established view is stored.
	* @return the resource path where the established view is stored
	*/
	public String getEstablishedViewPath() {
	return getDiscoveryResourcePath() + ESTABLISHED_VIEW_RESOURCE;
	}

	/**
	* Returns the resource path where ongoing votings are stored.
	* @return the resource path where ongoing votings are stored
	*/
	public String getOngoingVotingsPath() {
	return getDiscoveryResourcePath() + ONGOING_VOTING_RESOURCE;
	}

	/**
	* Returns the resource path where the previous view is stored.
	* @return the resource path where the previous view is stored
	*/
	public String getPreviousViewPath() {
	return getDiscoveryResourcePath() + PREVIOUS_VIEW_RESOURCE;
	}

	/**
	* Returns the repository descriptor key which is to be included in the
	* cluster leader election - or null.
	* <p>
	* When set, the value (treated as a boolean) of the repository descriptor
	* is prepended to the leader election id.
	* @return the repository descriptor key which is to be included in the
	* cluster leader election - or null
	*/
	public String getLeaderElectionRepositoryDescriptor() {
	return leaderElectionRepositoryDescriptor;
	}

	/**
	* Returns true when the value of the repository descriptor identified
	* via the property 'leaderElectionRepositoryDescriptor' should be
	* inverted - only applies when 'leaderElectionRepositoryDescriptor'
	* is configured of course.
	* @return true when property resulting from 'leaderElectionRepositoryDescriptor'
	* should be inverted, false if it should remain unchanged.
	*/
	public boolean shouldInvertRepositoryDescriptor() {
	return invertRepositoryDescriptor;
	}

	/**
	* @return true if hmac is enabled.
	*/
	public boolean isHmacEnabled() {
	return hmacEnabled;
	}

	/**
	* @return the shared key
	*/
	public String getSharedKey() {
	return sharedKey;
	}

	/**
	* @return the interval of the shared key for hmac.
	*/
	public long getKeyInterval() {
	return keyInterval;
	}

	/**
	* @return true if encryption is enabled.
	*/
	public boolean isEncryptionEnabled() {
	return encryptionEnabled;
	}

	/**
	* @return true if requests on the topology connector should be gzipped
	* (which only works if the server accepts that.. ie discovery.impl 1.0.4+)
	*/
	public boolean isGzipConnectorRequestsEnabled() {
	return gzipConnectorRequestsEnabled;
	}

	/**
	* @return true if the auto-stopping of local-loop topology connectors is enabled.
	*/
	public boolean isAutoStopLocalLoopEnabled() {
	return autoStopLocalLoopEnabled;
	}

	/**
	* Returns the backoff factor to be used for standby (loop) connectors
	* @return the backoff factor to be used for standby (loop) connectors
	*/
	public int getBackoffStandbyFactor() {
	return backoffStandbyFactor;
	}

	/**
	* Returns the (maximum) backoff factor to be used for stable connectors
	* @return the (maximum) backoff factor to be used for stable connectors
	*/
	public int getBackoffStableFactor() {
	return backoffStableFactor;
	}

	/**
	* Returns the backoff interval for standby (loop) connectors in seconds
	* @return the backoff interval for standby (loop) connectors in seconds
	*/
	public long getBackoffStandbyInterval() {
	final int factor = getBackoffStandbyFactor();
	if (factor<=1) {
	return -1;
	} else {
	return factor * getHeartbeatInterval();
	}
	}

	@Override
	public long getConnectorPingInterval() {
	return getHeartbeatInterval();
	}

	@Override
	public long getConnectorPingTimeout() {
	return getHeartbeatTimeout();
	}

	@Override
	public String getSyncTokenPath() {
	return getDiscoveryResourcePath() + SYNC_TOKEN_RESOURCE;
	}

	@Override
	public String getIdMapPath() {
	return getDiscoveryResourcePath() + ID_MAP_RESOURCE;
	}

	@Override
	public long getClusterSyncServiceTimeoutMillis() {
	return -1;
	}

	@Override
	public long getClusterSyncServiceIntervalMillis() {
	return 1000;
	}

	public boolean useSyncTokenService() {
	return useSyncTokenService;
	}

	}