| package org.apache.helix.view.dataprovider; |
| |
| /* |
| * 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. |
| */ |
| |
| import java.util.List; |
| import org.apache.helix.HelixConstants; |
| import org.apache.helix.HelixDataAccessor; |
| import org.apache.helix.HelixManager; |
| import org.apache.helix.HelixManagerFactory; |
| import org.apache.helix.InstanceType; |
| import org.apache.helix.NotificationContext; |
| import org.apache.helix.PropertyKey; |
| import org.apache.helix.PropertyType; |
| import org.apache.helix.api.config.ViewClusterSourceConfig; |
| import org.apache.helix.api.listeners.ExternalViewChangeListener; |
| import org.apache.helix.api.listeners.InstanceConfigChangeListener; |
| import org.apache.helix.api.listeners.LiveInstanceChangeListener; |
| import org.apache.helix.api.listeners.PreFetch; |
| import org.apache.helix.common.DedupEventProcessor; |
| import org.apache.helix.common.caches.BasicClusterDataCache; |
| import org.apache.helix.model.ExternalView; |
| import org.apache.helix.model.InstanceConfig; |
| import org.apache.helix.model.LiveInstance; |
| import org.apache.helix.view.common.ClusterViewEvent; |
| import org.apache.helix.zookeeper.zkclient.exception.ZkInterruptedException; |
| import org.slf4j.Logger; |
| import org.slf4j.LoggerFactory; |
| |
| /** |
| * SourceClusterDataProvider listens to changes in 1 source cluster, notifies cluster data cache, |
| * generates event for event processor and provide methods to read data cache |
| */ |
| public class SourceClusterDataProvider extends BasicClusterDataCache |
| implements InstanceConfigChangeListener, LiveInstanceChangeListener, |
| ExternalViewChangeListener { |
| private static final Logger LOG = LoggerFactory.getLogger(SourceClusterDataProvider.class); |
| |
| private final HelixManager _helixManager; |
| private final DedupEventProcessor<ClusterViewEvent.Type, ClusterViewEvent> _eventProcessor; |
| |
| protected ViewClusterSourceConfig _sourceClusterConfig; |
| private HelixDataAccessor _dataAccessor; |
| private PropertyKey.Builder _propertyKeyBuilder; |
| |
| public SourceClusterDataProvider(ViewClusterSourceConfig config, |
| DedupEventProcessor<ClusterViewEvent.Type, ClusterViewEvent> eventProcessor) { |
| super(config.getName()); |
| _eventProcessor = eventProcessor; |
| _sourceClusterConfig = config; |
| _helixManager = HelixManagerFactory.getZKHelixManager(config.getName(), |
| generateHelixManagerInstanceName(config.getName()), |
| InstanceType.SPECTATOR, config.getZkAddress()); |
| } |
| |
| public String getName() { |
| return _helixManager.getInstanceName(); |
| } |
| |
| /** |
| * Set up ClusterDataProvider. After setting up, the class should start listening |
| * on change events and perform corresponding reactions |
| * @throws Exception |
| */ |
| public void setup() throws Exception { |
| if (_helixManager != null && _helixManager.isConnected()) { |
| LOG.info(String.format("Data provider %s is already setup", _helixManager.getInstanceName())); |
| return; |
| } |
| try { |
| _helixManager.connect(); |
| for (PropertyType property : _sourceClusterConfig.getProperties()) { |
| HelixConstants.ChangeType changeType; |
| switch (property) { |
| case INSTANCES: |
| _helixManager.addInstanceConfigChangeListener(this); |
| changeType = HelixConstants.ChangeType.INSTANCE_CONFIG; |
| break; |
| case LIVEINSTANCES: |
| _helixManager.addLiveInstanceChangeListener(this); |
| changeType = HelixConstants.ChangeType.LIVE_INSTANCE; |
| break; |
| case EXTERNALVIEW: |
| _helixManager.addExternalViewChangeListener(this); |
| changeType = HelixConstants.ChangeType.EXTERNAL_VIEW; |
| break; |
| default: |
| LOG.warn(String |
| .format("Unsupported property type: %s. Skip adding listener", property.name())); |
| continue; |
| } |
| notifyDataChange(changeType); |
| } |
| _dataAccessor = _helixManager.getHelixDataAccessor(); |
| _propertyKeyBuilder = _dataAccessor.keyBuilder(); |
| LOG.info(String.format("Data provider %s (%s) started. Source cluster detail: %s", |
| _helixManager.getInstanceName(), hashCode(), |
| _sourceClusterConfig.toString())); |
| } catch(Exception e) { |
| shutdown(); |
| throw e; |
| } |
| } |
| |
| public void shutdown() { |
| // Clear cache to make sure memory is released |
| for (HelixConstants.ChangeType changeType : HelixConstants.ChangeType.values()) { |
| clearCache(changeType); |
| } |
| if (_helixManager != null && _helixManager.isConnected()) { |
| try { |
| _helixManager.disconnect(); |
| LOG.info( |
| String.format("Data provider %s (%s) shutdown cleanly.", _helixManager.getInstanceName(), hashCode())); |
| } catch (ZkInterruptedException e) { |
| // OK |
| } |
| } |
| } |
| |
| public void refreshCache() { |
| refresh(_dataAccessor); |
| } |
| |
| /** |
| * Get current instance config names. ListName is a more reliable way to find |
| * current instance config names. This is needed for ViewClusterRefresher when |
| * it is generating diffs to push to ViewCluster |
| * @return |
| */ |
| public List<String> getInstanceConfigNames() { |
| return _dataAccessor.getChildNames(_propertyKeyBuilder.instanceConfigs()); |
| } |
| |
| /** |
| * Get current live instance names. |
| * @return |
| */ |
| public List<String> getLiveInstanceNames() { |
| return _dataAccessor.getChildNames(_propertyKeyBuilder.liveInstances()); |
| } |
| |
| /** |
| * Get external view names |
| * @return |
| */ |
| public List<String> getExternalViewNames() { |
| return _dataAccessor.getChildNames(_propertyKeyBuilder.externalViews()); |
| } |
| |
| public List<PropertyType> getPropertiesToAggregate() { |
| return _sourceClusterConfig.getProperties(); |
| } |
| |
| @Override |
| @PreFetch(enabled = false) |
| public void onInstanceConfigChange(List<InstanceConfig> instanceConfigs, |
| NotificationContext context) { |
| queueEvent(context, ClusterViewEvent.Type.InstanceConfigChange, |
| HelixConstants.ChangeType.INSTANCE_CONFIG); |
| } |
| |
| @Override |
| @PreFetch(enabled = false) |
| public void onLiveInstanceChange(List<LiveInstance> liveInstances, |
| NotificationContext changeContext) { |
| queueEvent(changeContext, ClusterViewEvent.Type.LiveInstanceChange, |
| HelixConstants.ChangeType.LIVE_INSTANCE); |
| } |
| |
| @Override |
| @PreFetch(enabled = false) |
| public void onExternalViewChange(List<ExternalView> externalViewList, |
| NotificationContext changeContext) { |
| queueEvent(changeContext, ClusterViewEvent.Type.ExternalViewChange, |
| HelixConstants.ChangeType.EXTERNAL_VIEW); |
| } |
| |
| private void queueEvent(NotificationContext context, ClusterViewEvent.Type changeType, |
| HelixConstants.ChangeType cacheChangeType) |
| throws IllegalStateException { |
| // TODO: in case of FINALIZE, if we are not shutdown, re-connect helix manager and report error |
| if (context != null && context.getType() != NotificationContext.Type.FINALIZE) { |
| notifyDataChange(cacheChangeType); |
| _eventProcessor.queueEvent(changeType, new ClusterViewEvent(_clusterName, changeType)); |
| } else { |
| LOG.info("Skip queuing event from source cluster {}. ChangeType: {}, ContextType: {}", |
| _clusterName, cacheChangeType.name(), |
| context == null ? "NoContext" : context.getType().name()); |
| } |
| } |
| |
| private static String generateHelixManagerInstanceName(String clusterName) { |
| return String.format("SourceClusterSpectatorHelixManager-%s", clusterName); |
| } |
| |
| @Override |
| public String toString() { |
| return String.format("%s::%s", getClass().getSimpleName(), hashCode()); |
| } |
| } |