| package org.apache.helix.controller; |
| |
| /* |
| * 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.ArrayList; |
| import java.util.Arrays; |
| import java.util.Collections; |
| import java.util.HashMap; |
| import java.util.List; |
| import java.util.Map; |
| import java.util.Optional; |
| import java.util.Set; |
| import java.util.Timer; |
| import java.util.TimerTask; |
| import java.util.UUID; |
| import java.util.concurrent.ConcurrentHashMap; |
| import java.util.concurrent.Executors; |
| import java.util.concurrent.ScheduledExecutorService; |
| import java.util.concurrent.ThreadFactory; |
| import java.util.concurrent.TimeUnit; |
| import java.util.concurrent.atomic.AtomicReference; |
| |
| import com.google.common.collect.Sets; |
| import org.I0Itec.zkclient.exception.ZkInterruptedException; |
| import org.apache.helix.HelixDataAccessor; |
| import org.apache.helix.HelixManager; |
| import org.apache.helix.NotificationContext; |
| import org.apache.helix.PropertyKey; |
| import org.apache.helix.PropertyKey.Builder; |
| import org.apache.helix.api.exceptions.HelixMetaDataAccessException; |
| import org.apache.helix.api.listeners.ClusterConfigChangeListener; |
| import org.apache.helix.api.listeners.ControllerChangeListener; |
| import org.apache.helix.api.listeners.CurrentStateChangeListener; |
| import org.apache.helix.api.listeners.IdealStateChangeListener; |
| import org.apache.helix.api.listeners.InstanceConfigChangeListener; |
| import org.apache.helix.api.listeners.LiveInstanceChangeListener; |
| import org.apache.helix.api.listeners.MessageListener; |
| import org.apache.helix.api.listeners.PreFetch; |
| import org.apache.helix.api.listeners.ResourceConfigChangeListener; |
| import org.apache.helix.common.ClusterEventBlockingQueue; |
| import org.apache.helix.common.DedupEventProcessor; |
| import org.apache.helix.controller.dataproviders.BaseControllerDataProvider; |
| import org.apache.helix.controller.dataproviders.ResourceControllerDataProvider; |
| import org.apache.helix.controller.dataproviders.WorkflowControllerDataProvider; |
| import org.apache.helix.controller.pipeline.AsyncWorkerType; |
| import org.apache.helix.controller.pipeline.Pipeline; |
| import org.apache.helix.controller.pipeline.PipelineRegistry; |
| import org.apache.helix.controller.rebalancer.StatefulRebalancer; |
| import org.apache.helix.controller.rebalancer.waged.WagedRebalancer; |
| import org.apache.helix.controller.stages.AttributeName; |
| import org.apache.helix.controller.stages.BestPossibleStateCalcStage; |
| import org.apache.helix.controller.stages.ClusterEvent; |
| import org.apache.helix.controller.stages.ClusterEventType; |
| import org.apache.helix.controller.stages.CompatibilityCheckStage; |
| import org.apache.helix.controller.stages.CurrentStateComputationStage; |
| import org.apache.helix.controller.stages.ExternalViewComputeStage; |
| import org.apache.helix.controller.stages.IntermediateStateCalcStage; |
| import org.apache.helix.controller.stages.MaintenanceRecoveryStage; |
| import org.apache.helix.controller.stages.MessageSelectionStage; |
| import org.apache.helix.controller.stages.MessageThrottleStage; |
| import org.apache.helix.controller.stages.PersistAssignmentStage; |
| import org.apache.helix.controller.stages.ReadClusterDataStage; |
| import org.apache.helix.controller.stages.ResourceComputationStage; |
| import org.apache.helix.controller.stages.ResourceValidationStage; |
| import org.apache.helix.controller.stages.TargetExteralViewCalcStage; |
| import org.apache.helix.controller.stages.TaskGarbageCollectionStage; |
| import org.apache.helix.controller.stages.TopStateHandoffReportStage; |
| import org.apache.helix.controller.stages.resource.ResourceMessageDispatchStage; |
| import org.apache.helix.controller.stages.resource.ResourceMessageGenerationPhase; |
| import org.apache.helix.controller.stages.task.TaskMessageDispatchStage; |
| import org.apache.helix.controller.stages.task.TaskMessageGenerationPhase; |
| import org.apache.helix.controller.stages.task.TaskPersistDataStage; |
| import org.apache.helix.controller.stages.task.TaskSchedulingStage; |
| import org.apache.helix.model.ClusterConfig; |
| import org.apache.helix.model.CurrentState; |
| import org.apache.helix.model.IdealState; |
| import org.apache.helix.model.InstanceConfig; |
| import org.apache.helix.model.LiveInstance; |
| import org.apache.helix.model.MaintenanceSignal; |
| import org.apache.helix.model.Message; |
| import org.apache.helix.model.PauseSignal; |
| import org.apache.helix.model.ResourceConfig; |
| import org.apache.helix.monitoring.mbeans.ClusterEventMonitor; |
| import org.apache.helix.monitoring.mbeans.ClusterStatusMonitor; |
| import org.slf4j.Logger; |
| import org.slf4j.LoggerFactory; |
| |
| import static org.apache.helix.HelixConstants.ChangeType; |
| |
| /** |
| * Cluster Controllers main goal is to keep the cluster state as close as possible to Ideal State. |
| * It does this by listening to changes in cluster state and scheduling new tasks to get cluster |
| * state to best possible ideal state. Every instance of this class can control can control only one |
| * cluster Get all the partitions use IdealState, CurrentState and Messages <br> |
| * foreach partition <br> |
| * 1. get the (instance,state) from IdealState, CurrentState and PendingMessages <br> |
| * 2. compute best possible state (instance,state) pair. This needs previous step data and state |
| * model constraints <br> |
| * 3. compute the messages/tasks needed to move to 1 to 2 <br> |
| * 4. select the messages that can be sent, needs messages and state model constraints <br> |
| * 5. send messages |
| */ |
| public class GenericHelixController implements IdealStateChangeListener, |
| LiveInstanceChangeListener, MessageListener, CurrentStateChangeListener, |
| ControllerChangeListener, InstanceConfigChangeListener, ResourceConfigChangeListener, |
| ClusterConfigChangeListener { |
| private static final Logger logger = |
| LoggerFactory.getLogger(GenericHelixController.class.getName()); |
| |
| private static final long EVENT_THREAD_JOIN_TIMEOUT = 1000; |
| private static final int ASYNC_TASKS_THREADPOOL_SIZE = 10; |
| private final PipelineRegistry _registry; |
| private final PipelineRegistry _taskRegistry; |
| |
| final AtomicReference<Map<String, LiveInstance>> _lastSeenInstances; |
| final AtomicReference<Map<String, LiveInstance>> _lastSeenSessions; |
| |
| // By default not reporting status until controller status is changed to activate |
| // TODO This flag should be inside ClusterStatusMonitor. When false, no MBean registering. |
| private boolean _isMonitoring = false; |
| private final ClusterStatusMonitor _clusterStatusMonitor; |
| |
| /** |
| * A queue for controller events and a thread that will consume it |
| */ |
| private final ClusterEventBlockingQueue _eventQueue; |
| private final ClusterEventProcessor _eventThread; |
| |
| private final ClusterEventBlockingQueue _taskEventQueue; |
| private final ClusterEventProcessor _taskEventThread; |
| |
| private final Map<AsyncWorkerType, DedupEventProcessor<String, Runnable>> _asyncFIFOWorkerPool; |
| |
| private long _continousRebalanceFailureCount = 0; |
| |
| /** |
| * The _paused flag is checked by function handleEvent(), while if the flag is set handleEvent() |
| * will be no-op. Other event handling logic keeps the same when the flag is set. |
| */ |
| private boolean _paused; |
| private boolean _inMaintenanceMode; |
| |
| /** |
| * The timer that can periodically run the rebalancing pipeline. The timer will start if there is |
| * one resource group has the config to use the timer. |
| */ |
| Timer _periodicalRebalanceTimer = null; |
| long _timerPeriod = Long.MAX_VALUE; |
| |
| |
| /** |
| * The timer that triggers the on-demand rebalance pipeline. |
| */ |
| Timer _onDemandRebalanceTimer = null; |
| AtomicReference<RebalanceTask> _nextRebalanceTask = new AtomicReference<>(); |
| |
| /** |
| * A cache maintained across pipelines |
| */ |
| private final ResourceControllerDataProvider _resourceControlDataProvider; |
| private final WorkflowControllerDataProvider _workflowControlDataProvider; |
| private final ScheduledExecutorService _asyncTasksThreadPool; |
| |
| /** |
| * A record of last pipeline finish duration |
| */ |
| private long _lastPipelineEndTimestamp; |
| |
| private String _clusterName; |
| private final Set<Pipeline.Type> _enabledPipelineTypes; |
| |
| private HelixManager _helixManager; |
| |
| // Since the stateful rebalancer needs to be lazily constructed when the HelixManager instance is |
| // ready, the GenericHelixController is not constructed with a stateful rebalancer. This wrapper |
| // is to avoid the complexity of handling a nullable value in the event handling process. |
| // TODO Create the required stateful rebalancer only when it is used by any resource. |
| private final StatefulRebalancerRef _rebalancerRef = new StatefulRebalancerRef() { |
| @Override |
| protected StatefulRebalancer createRebalancer(HelixManager helixManager) { |
| return new WagedRebalancer(helixManager); |
| } |
| }; |
| |
| /** |
| * TODO: We should get rid of this once we move to: |
| * 1) ZK callback should go to ClusterDataCache and trigger data cache refresh only |
| * 2) then ClusterDataCache.refresh triggers rebalance pipeline. |
| */ |
| /* Map of cluster->GenrichelixController */ |
| private static Map<String, GenericHelixController> HelixControllerFactory = new ConcurrentHashMap<>(); |
| public static GenericHelixController getController(String clusterName) { |
| return HelixControllerFactory.get(clusterName); |
| } |
| |
| /** |
| * Default constructor that creates a default pipeline registry. This is sufficient in most cases, |
| * but if there is a some thing specific needed use another constructor where in you can pass a |
| * pipeline registry |
| */ |
| public GenericHelixController() { |
| this(createDefaultRegistry(Pipeline.Type.DEFAULT.name()), |
| createTaskRegistry(Pipeline.Type.TASK.name())); |
| } |
| |
| public GenericHelixController(String clusterName) { |
| this(createDefaultRegistry(Pipeline.Type.DEFAULT.name()), |
| createTaskRegistry(Pipeline.Type.TASK.name()), clusterName, |
| Sets.newHashSet(Pipeline.Type.TASK, Pipeline.Type.DEFAULT)); |
| } |
| |
| public GenericHelixController(String clusterName, Set<Pipeline.Type> enabledPipelins) { |
| this(createDefaultRegistry(Pipeline.Type.DEFAULT.name()), |
| createTaskRegistry(Pipeline.Type.TASK.name()), clusterName, enabledPipelins); |
| } |
| |
| class RebalanceTask extends TimerTask { |
| final HelixManager _manager; |
| final ClusterEventType _clusterEventType; |
| private final Optional<Boolean> _shouldRefreshCacheOption; |
| private long _nextRebalanceTime; |
| |
| public RebalanceTask(HelixManager manager, ClusterEventType clusterEventType) { |
| this(manager, clusterEventType, -1); |
| } |
| |
| public RebalanceTask(HelixManager manager, ClusterEventType clusterEventType, |
| long nextRebalanceTime) { |
| this(manager, clusterEventType, nextRebalanceTime, Optional.empty()); |
| } |
| |
| public RebalanceTask(HelixManager manager, ClusterEventType clusterEventType, |
| long nextRebalanceTime, boolean shouldRefreshCache) { |
| this(manager, clusterEventType, nextRebalanceTime, Optional.of(shouldRefreshCache)); |
| } |
| |
| private RebalanceTask(HelixManager manager, ClusterEventType clusterEventType, |
| long nextRebalanceTime, Optional<Boolean> shouldRefreshCacheOption) { |
| _manager = manager; |
| _clusterEventType = clusterEventType; |
| _nextRebalanceTime = nextRebalanceTime; |
| _shouldRefreshCacheOption = shouldRefreshCacheOption; |
| } |
| |
| public long getNextRebalanceTime() { |
| return _nextRebalanceTime; |
| } |
| |
| @Override |
| public void run() { |
| try { |
| if (_shouldRefreshCacheOption.orElse( |
| _clusterEventType.equals(ClusterEventType.PeriodicalRebalance) || _clusterEventType |
| .equals(ClusterEventType.OnDemandRebalance))) { |
| requestDataProvidersFullRefresh(); |
| |
| HelixDataAccessor accessor = _manager.getHelixDataAccessor(); |
| PropertyKey.Builder keyBuilder = accessor.keyBuilder(); |
| Map<String, LiveInstance> liveInstanceMap = |
| accessor.getChildValuesMap(keyBuilder.liveInstances()); |
| |
| if (liveInstanceMap != null && !liveInstanceMap.isEmpty()) { |
| NotificationContext changeContext = new NotificationContext(_manager); |
| changeContext.setType(NotificationContext.Type.CALLBACK); |
| synchronized (_manager) { |
| checkLiveInstancesObservation(new ArrayList<>(liveInstanceMap.values()), |
| changeContext); |
| } |
| } |
| } |
| forceRebalance(_manager, _clusterEventType); |
| } catch (Throwable ex) { |
| logger.error("Time task failed. Rebalance task type: " + _clusterEventType + ", cluster: " |
| + _clusterName, ex); |
| } |
| } |
| } |
| |
| /* Trigger a rebalance pipeline */ |
| private void forceRebalance(HelixManager manager, ClusterEventType eventType) { |
| NotificationContext changeContext = new NotificationContext(manager); |
| changeContext.setType(NotificationContext.Type.CALLBACK); |
| String uid = UUID.randomUUID().toString().substring(0, 8); |
| ClusterEvent event = new ClusterEvent(_clusterName, eventType, uid); |
| event.addAttribute(AttributeName.helixmanager.name(), changeContext.getManager()); |
| event.addAttribute(AttributeName.changeContext.name(), changeContext); |
| event.addAttribute(AttributeName.eventData.name(), new ArrayList<>()); |
| event.addAttribute(AttributeName.AsyncFIFOWorkerPool.name(), _asyncFIFOWorkerPool); |
| |
| enqueueEvent(_taskEventQueue, event); |
| enqueueEvent(_eventQueue, event.clone(uid)); |
| logger.info(String |
| .format("Controller rebalance pipeline triggered with event type: %s for cluster %s", |
| eventType, _clusterName)); |
| } |
| |
| /** |
| * Starts the rebalancing timer with the specified period. Start the timer if necessary; If the |
| * period is smaller than the current period, cancel the current timer and use the new period. |
| */ |
| void startPeriodRebalance(long period, HelixManager manager) { |
| if (period != _timerPeriod) { |
| logger.info("Controller starting periodical rebalance timer at period " + period); |
| if (_periodicalRebalanceTimer != null) { |
| _periodicalRebalanceTimer.cancel(); |
| } |
| _periodicalRebalanceTimer = new Timer(true); |
| _timerPeriod = period; |
| _periodicalRebalanceTimer |
| .scheduleAtFixedRate(new RebalanceTask(manager, ClusterEventType.PeriodicalRebalance), |
| _timerPeriod, _timerPeriod); |
| } else { |
| logger.info("Controller already has periodical rebalance timer at period " + _timerPeriod); |
| } |
| } |
| |
| /** |
| * Stops the rebalancing timer. |
| */ |
| void stopPeriodRebalance() { |
| logger.info("Controller stopping periodical rebalance timer at period " + _timerPeriod); |
| if (_periodicalRebalanceTimer != null) { |
| _periodicalRebalanceTimer.cancel(); |
| _periodicalRebalanceTimer = null; |
| _timerPeriod = Long.MAX_VALUE; |
| logger.info("Controller stopped periodical rebalance timer at period " + _timerPeriod); |
| } |
| } |
| |
| /** |
| * This function is deprecated. Please use RebalanceUtil.scheduleInstantPipeline method instead. |
| * schedule a future rebalance pipeline run, delayed at given time. |
| */ |
| @Deprecated |
| public void scheduleRebalance(long rebalanceTime) { |
| if (_helixManager == null) { |
| logger.warn( |
| "Failed to schedule a future pipeline run for cluster " + _clusterName + " helix manager is null!"); |
| return; |
| } |
| |
| long current = System.currentTimeMillis(); |
| long delay = rebalanceTime - current; |
| |
| if (rebalanceTime > current) { |
| RebalanceTask preTask = _nextRebalanceTask.get(); |
| if (preTask != null && preTask.getNextRebalanceTime() > current |
| && preTask.getNextRebalanceTime() < rebalanceTime) { |
| // already have a earlier rebalance scheduled, no need to schedule again. |
| return; |
| } |
| |
| RebalanceTask newTask = |
| new RebalanceTask(_helixManager, ClusterEventType.OnDemandRebalance, rebalanceTime); |
| |
| _onDemandRebalanceTimer.schedule(newTask, delay); |
| logger.info( |
| "Scheduled a future pipeline run for cluster " + _helixManager.getClusterName() + " in delay " |
| + delay); |
| |
| preTask = _nextRebalanceTask.getAndSet(newTask); |
| if (preTask != null) { |
| preTask.cancel(); |
| } |
| } |
| } |
| |
| /** |
| * Schedule an on demand rebalance pipeline. |
| * @param delay |
| */ |
| @Deprecated |
| public void scheduleOnDemandRebalance(long delay) { |
| scheduleOnDemandRebalance(delay, true); |
| } |
| |
| /** |
| * Schedule an on demand rebalance pipeline. |
| * @param delay |
| * @param shouldRefreshCache true if refresh the cache before scheduling a rebalance. |
| */ |
| public void scheduleOnDemandRebalance(long delay, boolean shouldRefreshCache) { |
| if (_helixManager == null) { |
| logger.error("Failed to schedule a future pipeline run for cluster {}. Helix manager is null!", |
| _clusterName); |
| return; |
| } |
| long currentTime = System.currentTimeMillis(); |
| long rebalanceTime = currentTime + delay; |
| if (delay > 0) { |
| RebalanceTask preTask = _nextRebalanceTask.get(); |
| if (preTask != null && preTask.getNextRebalanceTime() > currentTime |
| && preTask.getNextRebalanceTime() < rebalanceTime) { |
| // already have a earlier rebalance scheduled, no need to schedule again. |
| return; |
| } |
| } |
| |
| RebalanceTask newTask = |
| new RebalanceTask(_helixManager, ClusterEventType.OnDemandRebalance, rebalanceTime, |
| shouldRefreshCache); |
| |
| _onDemandRebalanceTimer.schedule(newTask, delay); |
| logger.info("Scheduled instant pipeline run for cluster {}." , _helixManager.getClusterName()); |
| |
| RebalanceTask preTask = _nextRebalanceTask.getAndSet(newTask); |
| if (preTask != null) { |
| preTask.cancel(); |
| } |
| } |
| |
| private static PipelineRegistry createDefaultRegistry(String pipelineName) { |
| logger.info("createDefaultRegistry"); |
| synchronized (GenericHelixController.class) { |
| PipelineRegistry registry = new PipelineRegistry(); |
| |
| // cluster data cache refresh |
| Pipeline dataRefresh = new Pipeline(pipelineName); |
| dataRefresh.addStage(new ReadClusterDataStage()); |
| |
| // data pre-process pipeline |
| Pipeline dataPreprocess = new Pipeline(pipelineName); |
| dataPreprocess.addStage(new ResourceComputationStage()); |
| dataPreprocess.addStage(new ResourceValidationStage()); |
| dataPreprocess.addStage(new CurrentStateComputationStage()); |
| dataPreprocess.addStage(new TopStateHandoffReportStage()); |
| |
| // rebalance pipeline |
| Pipeline rebalancePipeline = new Pipeline(pipelineName); |
| rebalancePipeline.addStage(new BestPossibleStateCalcStage()); |
| rebalancePipeline.addStage(new IntermediateStateCalcStage()); |
| // Need to add MaintenanceRecoveryStage here because MAX_PARTITIONS_PER_INSTANCE check could |
| // only occur after IntermediateStateCalcStage calculation |
| rebalancePipeline.addStage(new MaintenanceRecoveryStage()); |
| rebalancePipeline.addStage(new ResourceMessageGenerationPhase()); |
| rebalancePipeline.addStage(new MessageSelectionStage()); |
| rebalancePipeline.addStage(new MessageThrottleStage()); |
| rebalancePipeline.addStage(new ResourceMessageDispatchStage()); |
| rebalancePipeline.addStage(new PersistAssignmentStage()); |
| rebalancePipeline.addStage(new TargetExteralViewCalcStage()); |
| |
| // external view generation |
| Pipeline externalViewPipeline = new Pipeline(pipelineName); |
| externalViewPipeline.addStage(new ExternalViewComputeStage()); |
| |
| // backward compatibility check |
| Pipeline liveInstancePipeline = new Pipeline(pipelineName); |
| liveInstancePipeline.addStage(new CompatibilityCheckStage()); |
| |
| // auto-exit maintenance mode if applicable |
| Pipeline autoExitMaintenancePipeline = new Pipeline(pipelineName); |
| autoExitMaintenancePipeline.addStage(new MaintenanceRecoveryStage()); |
| |
| registry.register(ClusterEventType.IdealStateChange, dataRefresh, dataPreprocess, rebalancePipeline); |
| registry.register(ClusterEventType.CurrentStateChange, dataRefresh, dataPreprocess, externalViewPipeline, rebalancePipeline); |
| registry.register(ClusterEventType.InstanceConfigChange, dataRefresh, dataPreprocess, rebalancePipeline); |
| registry.register(ClusterEventType.ResourceConfigChange, dataRefresh, dataPreprocess, rebalancePipeline); |
| registry.register(ClusterEventType.ClusterConfigChange, dataRefresh, autoExitMaintenancePipeline, dataPreprocess, rebalancePipeline); |
| registry.register(ClusterEventType.LiveInstanceChange, dataRefresh, autoExitMaintenancePipeline, liveInstancePipeline, dataPreprocess, externalViewPipeline, rebalancePipeline); |
| registry.register(ClusterEventType.MessageChange, dataRefresh, dataPreprocess, rebalancePipeline); |
| registry.register(ClusterEventType.Resume, dataRefresh, dataPreprocess, externalViewPipeline, rebalancePipeline); |
| registry.register(ClusterEventType.PeriodicalRebalance, dataRefresh, autoExitMaintenancePipeline, dataPreprocess, externalViewPipeline, rebalancePipeline); |
| registry.register(ClusterEventType.OnDemandRebalance, dataRefresh, autoExitMaintenancePipeline, dataPreprocess, externalViewPipeline, rebalancePipeline); |
| return registry; |
| } |
| } |
| |
| private static PipelineRegistry createTaskRegistry(String pipelineName) { |
| logger.info("createTaskRegistry"); |
| synchronized (GenericHelixController.class) { |
| PipelineRegistry registry = new PipelineRegistry(); |
| |
| // cluster data cache refresh |
| Pipeline dataRefresh = new Pipeline(pipelineName); |
| dataRefresh.addStage(new ReadClusterDataStage()); |
| |
| // data pre-process pipeline |
| Pipeline dataPreprocess = new Pipeline(pipelineName); |
| dataPreprocess.addStage(new ResourceComputationStage()); |
| dataPreprocess.addStage(new ResourceValidationStage()); |
| dataPreprocess.addStage(new CurrentStateComputationStage()); |
| |
| // rebalance pipeline |
| Pipeline rebalancePipeline = new Pipeline(pipelineName); |
| rebalancePipeline.addStage(new TaskSchedulingStage()); |
| rebalancePipeline.addStage(new TaskPersistDataStage()); |
| rebalancePipeline.addStage(new TaskGarbageCollectionStage()); |
| rebalancePipeline.addStage(new TaskMessageGenerationPhase()); |
| rebalancePipeline.addStage(new TaskMessageDispatchStage()); |
| |
| // backward compatibility check |
| Pipeline liveInstancePipeline = new Pipeline(pipelineName); |
| liveInstancePipeline.addStage(new CompatibilityCheckStage()); |
| |
| registry.register(ClusterEventType.IdealStateChange, dataRefresh, dataPreprocess, |
| rebalancePipeline); |
| registry.register(ClusterEventType.CurrentStateChange, dataRefresh, dataPreprocess, |
| rebalancePipeline); |
| registry.register(ClusterEventType.InstanceConfigChange, dataRefresh, dataPreprocess, |
| rebalancePipeline); |
| registry.register(ClusterEventType.ResourceConfigChange, dataRefresh, dataPreprocess, |
| rebalancePipeline); |
| registry.register(ClusterEventType.ClusterConfigChange, dataRefresh, dataPreprocess, |
| rebalancePipeline); |
| registry.register(ClusterEventType.LiveInstanceChange, dataRefresh, liveInstancePipeline, |
| dataPreprocess, rebalancePipeline); |
| registry |
| .register(ClusterEventType.MessageChange, dataRefresh, dataPreprocess, rebalancePipeline); |
| registry.register(ClusterEventType.Resume, dataRefresh, dataPreprocess, rebalancePipeline); |
| registry.register(ClusterEventType.PeriodicalRebalance, dataRefresh, dataPreprocess, |
| rebalancePipeline); |
| registry.register(ClusterEventType.OnDemandRebalance, dataRefresh, dataPreprocess, |
| rebalancePipeline); |
| return registry; |
| } |
| } |
| |
| // TODO: refactor the constructor as providing both registry but only enabling one looks confusing |
| public GenericHelixController(PipelineRegistry registry, PipelineRegistry taskRegistry) { |
| this(registry, taskRegistry, null, Sets.newHashSet( |
| Pipeline.Type.TASK, Pipeline.Type.DEFAULT)); |
| } |
| |
| private GenericHelixController(PipelineRegistry registry, PipelineRegistry taskRegistry, |
| final String clusterName, Set<Pipeline.Type> enabledPipelineTypes) { |
| _paused = false; |
| _enabledPipelineTypes = enabledPipelineTypes; |
| _registry = registry; |
| _taskRegistry = taskRegistry; |
| _lastSeenInstances = new AtomicReference<>(); |
| _lastSeenSessions = new AtomicReference<>(); |
| _clusterName = clusterName; |
| _lastPipelineEndTimestamp = TopStateHandoffReportStage.TIMESTAMP_NOT_RECORDED; |
| _clusterStatusMonitor = new ClusterStatusMonitor(_clusterName); |
| |
| _asyncTasksThreadPool = |
| Executors.newScheduledThreadPool(ASYNC_TASKS_THREADPOOL_SIZE, new ThreadFactory() { |
| @Override public Thread newThread(Runnable r) { |
| return new Thread(r, "HelixController-async_tasks-" + _clusterName); |
| } |
| }); |
| _asyncFIFOWorkerPool = new HashMap<>(); |
| initializeAsyncFIFOWorkers(); |
| |
| _onDemandRebalanceTimer = new Timer(true); |
| |
| // initialize pipelines at the end so we have everything else prepared |
| if (_enabledPipelineTypes.contains(Pipeline.Type.DEFAULT)) { |
| logger.info("Initializing {} pipeline", Pipeline.Type.DEFAULT.name()); |
| _resourceControlDataProvider = new ResourceControllerDataProvider(clusterName); |
| _eventQueue = new ClusterEventBlockingQueue(); |
| _eventThread = new ClusterEventProcessor(_resourceControlDataProvider, _eventQueue, |
| "default-" + clusterName); |
| initPipeline(_eventThread, _resourceControlDataProvider); |
| logger.info("Initialized {} pipeline", Pipeline.Type.DEFAULT.name()); |
| } else { |
| _eventQueue = null; |
| _resourceControlDataProvider = null; |
| _eventThread = null; |
| } |
| |
| if (_enabledPipelineTypes.contains(Pipeline.Type.TASK)) { |
| logger.info("Initializing {} pipeline", Pipeline.Type.TASK.name()); |
| _workflowControlDataProvider = new WorkflowControllerDataProvider(clusterName); |
| _taskEventQueue = new ClusterEventBlockingQueue(); |
| _taskEventThread = new ClusterEventProcessor(_workflowControlDataProvider, _taskEventQueue, |
| "task-" + clusterName); |
| initPipeline(_taskEventThread, _workflowControlDataProvider); |
| logger.info("Initialized {} pipeline", Pipeline.Type.TASK.name()); |
| } else { |
| _workflowControlDataProvider = null; |
| _taskEventQueue = null; |
| _taskEventThread = null; |
| } |
| |
| if (clusterName != null) { |
| HelixControllerFactory.put(clusterName, this); |
| } |
| } |
| |
| private void initializeAsyncFIFOWorkers() { |
| for (AsyncWorkerType type : AsyncWorkerType.values()) { |
| DedupEventProcessor<String, Runnable> worker = |
| new DedupEventProcessor<String, Runnable>(_clusterName, type.name()) { |
| @Override |
| protected void handleEvent(Runnable event) { |
| // TODO: retry when queue is empty and event.run() failed? |
| event.run(); |
| } |
| }; |
| worker.start(); |
| _asyncFIFOWorkerPool.put(type, worker); |
| logger.info("Started async worker {}", worker.getName()); |
| } |
| } |
| |
| private void shutdownAsyncFIFOWorkers() { |
| for (DedupEventProcessor processor : _asyncFIFOWorkerPool.values()) { |
| processor.shutdown(); |
| logger.info("Shutdown async worker {}", processor.getName()); |
| } |
| } |
| |
| private boolean isEventQueueEmpty(boolean taskQueue) { |
| if (taskQueue) { |
| return _taskEventQueue == null || _taskEventQueue.isEmpty(); |
| } else { |
| return _eventQueue == null || _eventQueue.isEmpty(); |
| } |
| } |
| |
| /** |
| * lock-always: caller always needs to obtain an external lock before call, calls to handleEvent() |
| * should be serialized |
| * @param event cluster event to handle |
| */ |
| private void handleEvent(ClusterEvent event, BaseControllerDataProvider dataProvider) { |
| HelixManager manager = event.getAttribute(AttributeName.helixmanager.name()); |
| if (manager == null) { |
| logger.error("No cluster manager in event:" + event.getEventType()); |
| return; |
| } |
| |
| // Event handling happens in a different thread from the onControllerChange processing thread. |
| // Thus, there are several possible conditions. |
| // 1. Event handled after leadership acquired. So we will have a valid rebalancer for the |
| // event processing. |
| // 2. Event handled shortly after leadership relinquished. And the rebalancer has not been |
| // marked as invalid yet. So the event will be processed the same as case one. |
| // 3. Event is leftover from the previous session, and it is handled when the controller |
| // regains the leadership. The rebalancer will be reset before being used. That is the |
| // expected behavior so as to avoid inconsistent rebalance result. |
| // 4. Event handled shortly after leadership relinquished. And the rebalancer has been marked |
| // as invalid. So we reset the rebalancer. But the later isLeader() check will return false and |
| // the pipeline will be triggered. So the reset rebalancer won't be used before the controller |
| // regains leadership. |
| event.addAttribute(AttributeName.STATEFUL_REBALANCER.name(), |
| _rebalancerRef.getRebalancer(manager)); |
| |
| if (!manager.isLeader()) { |
| logger.error("Cluster manager: " + manager.getInstanceName() + " is not leader for " + manager |
| .getClusterName() + ". Pipeline will not be invoked"); |
| return; |
| } |
| |
| _helixManager = manager; |
| |
| // TODO If init controller with paused = true, it may not take effect immediately |
| // _paused is default false. If any events come before controllerChangeEvent, the controller |
| // will be excuting in un-paused mode. Which might not be the config in ZK. |
| if (_paused) { |
| logger.info("Cluster " + manager.getClusterName() + " is paused. Ignoring the event:" + event |
| .getEventType()); |
| return; |
| } |
| |
| NotificationContext context = null; |
| if (event.getAttribute(AttributeName.changeContext.name()) != null) { |
| context = event.getAttribute(AttributeName.changeContext.name()); |
| } |
| |
| if (context != null) { |
| if (context.getType() == NotificationContext.Type.FINALIZE) { |
| stopPeriodRebalance(); |
| logger.info("Get FINALIZE notification, skip the pipeline. Event :" + event.getEventType()); |
| return; |
| } else { |
| // TODO: should be in the initialization of controller. |
| if (_resourceControlDataProvider != null) { |
| checkRebalancingTimer(manager, Collections.<IdealState>emptyList(), dataProvider.getClusterConfig()); |
| } |
| if (_isMonitoring) { |
| event.addAttribute(AttributeName.clusterStatusMonitor.name(), _clusterStatusMonitor); |
| } |
| } |
| } |
| |
| dataProvider.setClusterEventId(event.getEventId()); |
| event.addAttribute(AttributeName.LastRebalanceFinishTimeStamp.name(), _lastPipelineEndTimestamp); |
| |
| // Prepare ClusterEvent |
| // TODO (harry): this is a temporal workaround - after controller is separated we should not |
| // have this instanceof clauses |
| List<Pipeline> pipelines; |
| boolean isTaskFrameworkPipeline = false; |
| |
| if (dataProvider instanceof ResourceControllerDataProvider) { |
| pipelines = _registry |
| .getPipelinesForEvent(event.getEventType()); |
| } else if (dataProvider instanceof WorkflowControllerDataProvider) { |
| pipelines = _taskRegistry |
| .getPipelinesForEvent(event.getEventType()); |
| isTaskFrameworkPipeline = true; |
| } else { |
| logger.warn(String |
| .format("No %s pipeline to run for event: %s::%s", dataProvider.getPipelineName(), |
| event.getEventType(), event.getEventId())); |
| return; |
| } |
| event.addAttribute(AttributeName.ControllerDataProvider.name(), dataProvider); |
| |
| logger.info(String.format("START: Invoking %s controller pipeline for cluster %s event: %s %s", |
| manager.getClusterName(), dataProvider.getPipelineName(), event.getEventType(), |
| event.getEventId())); |
| |
| long startTime = System.currentTimeMillis(); |
| boolean rebalanceFail = false; |
| for (Pipeline pipeline : pipelines) { |
| event.addAttribute(AttributeName.PipelineType.name(), pipeline.getPipelineType()); |
| try { |
| pipeline.handle(event); |
| pipeline.finish(); |
| } catch (Exception e) { |
| logger.error( |
| "Exception while executing {} pipeline: {} for cluster {}. Will not continue to next pipeline", |
| dataProvider.getPipelineName(), _clusterName, Arrays.toString(e.getStackTrace())); |
| |
| if (e instanceof HelixMetaDataAccessException) { |
| rebalanceFail = true; |
| // If pipeline failed due to read/write fails to zookeeper, retry the pipeline. |
| dataProvider.requireFullRefresh(); |
| logger.warn("Rebalance pipeline failed due to read failure from zookeeper, cluster: " + _clusterName); |
| |
| // only push a retry event when there is no pending event in the corresponding event queue. |
| if (isEventQueueEmpty(isTaskFrameworkPipeline)) { |
| _continousRebalanceFailureCount ++; |
| long delay = getRetryDelay(_continousRebalanceFailureCount); |
| if (delay == 0) { |
| forceRebalance(manager, ClusterEventType.RetryRebalance); |
| } else { |
| _asyncTasksThreadPool |
| .schedule(new RebalanceTask(manager, ClusterEventType.RetryRebalance), delay, |
| TimeUnit.MILLISECONDS); |
| } |
| logger.info("Retry rebalance pipeline with delay " + delay + "ms for cluster: " + _clusterName); |
| } |
| } |
| _clusterStatusMonitor.reportRebalanceFailure(); |
| break; |
| } |
| } |
| if (!rebalanceFail) { |
| _continousRebalanceFailureCount = 0; |
| } |
| |
| _lastPipelineEndTimestamp = System.currentTimeMillis(); |
| logger.info("END: Invoking {} controller pipeline for event {}::{} for cluster {}, took {} ms", |
| dataProvider.getPipelineName(), event.getEventType(), event.getEventId(), _clusterName, |
| _lastPipelineEndTimestamp - startTime); |
| |
| if (!isTaskFrameworkPipeline) { |
| // report event process durations |
| NotificationContext notificationContext = |
| event.getAttribute(AttributeName.changeContext.name()); |
| long enqueueTime = event.getCreationTime(); |
| long zkCallbackTime; |
| StringBuilder sb = new StringBuilder(); |
| if (notificationContext != null) { |
| zkCallbackTime = notificationContext.getCreationTime(); |
| if (_isMonitoring) { |
| _clusterStatusMonitor |
| .updateClusterEventDuration(ClusterEventMonitor.PhaseName.Callback.name(), |
| enqueueTime - zkCallbackTime); |
| } |
| sb.append(String.format("Callback time for event: %s took: %s ms\n", event.getEventType(), |
| enqueueTime - zkCallbackTime)); |
| } |
| if (_isMonitoring) { |
| _clusterStatusMonitor |
| .updateClusterEventDuration(ClusterEventMonitor.PhaseName.InQueue.name(), |
| startTime - enqueueTime); |
| _clusterStatusMonitor |
| .updateClusterEventDuration(ClusterEventMonitor.PhaseName.TotalProcessed.name(), |
| _lastPipelineEndTimestamp - startTime); |
| } |
| sb.append(String.format("InQueue time for event: %s took: %s ms\n", event.getEventType(), |
| startTime - enqueueTime)); |
| sb.append(String.format("TotalProcessed time for event: %s took: %s ms", event.getEventType(), |
| _lastPipelineEndTimestamp - startTime)); |
| logger.info(sb.toString()); |
| } |
| |
| // If event handling happens before controller deactivate, the process may write unnecessary |
| // MBeans to monitoring after the monitor is disabled. |
| // So reset ClusterStatusMonitor according to it's status after all event handling. |
| // TODO remove this once clusterStatusMonitor blocks any MBean register on isMonitoring = false. |
| resetClusterStatusMonitor(); |
| } |
| |
| /** |
| * get the delay on next retry rebalance due to zk read failure, We use a simple exponential |
| * backoff to make the delay between [10ms, 1000ms] |
| */ |
| private long getRetryDelay(long failCount) { |
| int lowLimit = 5; |
| if (failCount <= lowLimit) { |
| return 0; |
| } |
| long backoff = (long) (Math.pow(2, failCount - lowLimit) * 10); |
| return Math.min(backoff, 1000); |
| } |
| |
| @Override |
| @PreFetch(enabled = false) |
| public void onStateChange(String instanceName, List<CurrentState> statesInfo, |
| NotificationContext changeContext) { |
| logger.info("START: GenericClusterController.onStateChange()"); |
| notifyCaches(changeContext, ChangeType.CURRENT_STATE); |
| pushToEventQueues(ClusterEventType.CurrentStateChange, changeContext, Collections |
| .<String, Object>singletonMap(AttributeName.instanceName.name(), instanceName)); |
| logger.info("END: GenericClusterController.onStateChange()"); |
| } |
| |
| @Override |
| @PreFetch(enabled = false) |
| public void onMessage(String instanceName, List<Message> messages, |
| NotificationContext changeContext) { |
| logger.info("START: GenericClusterController.onMessage() for cluster " + _clusterName); |
| notifyCaches(changeContext, ChangeType.MESSAGE); |
| pushToEventQueues(ClusterEventType.MessageChange, changeContext, |
| Collections.<String, Object>singletonMap(AttributeName.instanceName.name(), instanceName)); |
| |
| if (_isMonitoring && messages != null) { |
| _clusterStatusMonitor.addMessageQueueSize(instanceName, messages.size()); |
| } |
| |
| logger.info("END: GenericClusterController.onMessage() for cluster " + _clusterName); |
| } |
| |
| @Override |
| public void onLiveInstanceChange(List<LiveInstance> liveInstances, |
| NotificationContext changeContext) { |
| logger.info("START: Generic GenericClusterController.onLiveInstanceChange() for cluster " + _clusterName); |
| notifyCaches(changeContext, ChangeType.LIVE_INSTANCE); |
| |
| if (liveInstances == null) { |
| liveInstances = Collections.emptyList(); |
| } |
| |
| // Go though the live instance list and make sure that we are observing them |
| // accordingly. The action is done regardless of the paused flag. |
| if (changeContext.getType() == NotificationContext.Type.INIT |
| || changeContext.getType() == NotificationContext.Type.CALLBACK) { |
| checkLiveInstancesObservation(liveInstances, changeContext); |
| } else if (changeContext.getType() == NotificationContext.Type.FINALIZE) { |
| // on finalize, should remove all message/current-state listeners |
| logger.info("remove message/current-state listeners. lastSeenInstances: " + _lastSeenInstances |
| + ", lastSeenSessions: " + _lastSeenSessions); |
| liveInstances = Collections.emptyList(); |
| checkLiveInstancesObservation(liveInstances, changeContext); |
| } |
| |
| pushToEventQueues(ClusterEventType.LiveInstanceChange, changeContext, |
| Collections.<String, Object>singletonMap(AttributeName.eventData.name(), liveInstances)); |
| |
| logger.info( |
| "END: Generic GenericClusterController.onLiveInstanceChange() for cluster " + _clusterName); |
| } |
| |
| private void checkRebalancingTimer(HelixManager manager, List<IdealState> idealStates, |
| ClusterConfig clusterConfig) { |
| if (manager.getConfigAccessor() == null) { |
| logger.warn(manager.getInstanceName() |
| + " config accessor doesn't exist. should be in file-based mode."); |
| return; |
| } |
| |
| long minPeriod = Long.MAX_VALUE; |
| if (clusterConfig != null) { |
| long period = clusterConfig.getRebalanceTimePeriod(); |
| if (period > 0 && minPeriod > period) { |
| minPeriod = period; |
| } |
| } |
| |
| // TODO: resource level rebalance does not make sense, to remove it! |
| for (IdealState idealState : idealStates) { |
| long period = idealState.getRebalanceTimerPeriod(); |
| if (period > 0 && minPeriod > period) { |
| minPeriod = period; |
| } |
| } |
| |
| if (minPeriod != Long.MAX_VALUE) { |
| startPeriodRebalance(minPeriod, manager); |
| } else { |
| stopPeriodRebalance(); |
| } |
| } |
| |
| @Override |
| @PreFetch(enabled = false) |
| public void onIdealStateChange(List<IdealState> idealStates, NotificationContext changeContext) { |
| logger.info( |
| "START: Generic GenericClusterController.onIdealStateChange() for cluster " + _clusterName); |
| notifyCaches(changeContext, ChangeType.IDEAL_STATE); |
| pushToEventQueues(ClusterEventType.IdealStateChange, changeContext, |
| Collections.<String, Object>emptyMap()); |
| |
| if (changeContext.getType() != NotificationContext.Type.FINALIZE) { |
| HelixManager manager = changeContext.getManager(); |
| if (manager != null) { |
| HelixDataAccessor dataAccessor = changeContext.getManager().getHelixDataAccessor(); |
| checkRebalancingTimer(changeContext.getManager(), idealStates, |
| (ClusterConfig) dataAccessor.getProperty(dataAccessor.keyBuilder().clusterConfig())); |
| } |
| } |
| |
| logger.info("END: GenericClusterController.onIdealStateChange() for cluster " + _clusterName); |
| } |
| |
| @Override |
| @PreFetch(enabled = false) |
| public void onInstanceConfigChange(List<InstanceConfig> instanceConfigs, |
| NotificationContext changeContext) { |
| logger.info( |
| "START: GenericClusterController.onInstanceConfigChange() for cluster " + _clusterName); |
| notifyCaches(changeContext, ChangeType.INSTANCE_CONFIG); |
| pushToEventQueues(ClusterEventType.InstanceConfigChange, changeContext, |
| Collections.<String, Object>emptyMap()); |
| logger.info( |
| "END: GenericClusterController.onInstanceConfigChange() for cluster " + _clusterName); |
| } |
| |
| @Override |
| @PreFetch(enabled = false) |
| public void onResourceConfigChange( |
| List<ResourceConfig> resourceConfigs, NotificationContext context) { |
| logger.info( |
| "START: GenericClusterController.onResourceConfigChange() for cluster " + _clusterName); |
| notifyCaches(context, ChangeType.RESOURCE_CONFIG); |
| pushToEventQueues(ClusterEventType.ResourceConfigChange, context, |
| Collections.<String, Object>emptyMap()); |
| logger |
| .info("END: GenericClusterController.onResourceConfigChange() for cluster " + _clusterName); |
| } |
| |
| @Override |
| @PreFetch(enabled = false) |
| public void onClusterConfigChange(ClusterConfig clusterConfig, |
| NotificationContext context) { |
| logger.info( |
| "START: GenericClusterController.onClusterConfigChange() for cluster " + _clusterName); |
| notifyCaches(context, ChangeType.CLUSTER_CONFIG); |
| pushToEventQueues(ClusterEventType.ClusterConfigChange, context, |
| Collections.<String, Object>emptyMap()); |
| logger |
| .info("END: GenericClusterController.onClusterConfigChange() for cluster " + _clusterName); |
| } |
| |
| private void notifyCaches(NotificationContext context, ChangeType changeType) { |
| if (context == null || context.getType() != NotificationContext.Type.CALLBACK) { |
| requestDataProvidersFullRefresh(); |
| } else { |
| updateDataChangeInProvider(changeType, context.getPathChanged()); |
| } |
| } |
| |
| private void updateDataChangeInProvider(ChangeType type, String path) { |
| if (_resourceControlDataProvider != null) { |
| _resourceControlDataProvider.notifyDataChange(type, path); |
| } |
| |
| if (_workflowControlDataProvider != null) { |
| _workflowControlDataProvider.notifyDataChange(type, path); |
| } |
| } |
| |
| private void requestDataProvidersFullRefresh() { |
| if (_resourceControlDataProvider != null) { |
| _resourceControlDataProvider.requireFullRefresh(); |
| } |
| |
| if (_workflowControlDataProvider != null) { |
| _workflowControlDataProvider.requireFullRefresh(); |
| } |
| } |
| |
| private void pushToEventQueues(ClusterEventType eventType, NotificationContext changeContext, |
| Map<String, Object> eventAttributes) { |
| // No need for completed UUID, prefixed should be fine |
| String uid = UUID.randomUUID().toString().substring(0, 8); |
| ClusterEvent event = new ClusterEvent(_clusterName, eventType, |
| String.format("%s_%s", uid, Pipeline.Type.DEFAULT.name())); |
| event.addAttribute(AttributeName.helixmanager.name(), changeContext.getManager()); |
| event.addAttribute(AttributeName.changeContext.name(), changeContext); |
| event.addAttribute(AttributeName.AsyncFIFOWorkerPool.name(), _asyncFIFOWorkerPool); |
| for (Map.Entry<String, Object> attr : eventAttributes.entrySet()) { |
| event.addAttribute(attr.getKey(), attr.getValue()); |
| } |
| enqueueEvent(_eventQueue, event); |
| enqueueEvent(_taskEventQueue, |
| event.clone(String.format("%s_%s", uid, Pipeline.Type.TASK.name()))); |
| } |
| |
| private void enqueueEvent(ClusterEventBlockingQueue queue, ClusterEvent event) { |
| if (event == null || queue == null) { |
| return; |
| } |
| queue.put(event); |
| } |
| |
| @Override |
| public void onControllerChange(NotificationContext changeContext) { |
| logger.info("START: GenericClusterController.onControllerChange() for cluster " + _clusterName); |
| |
| requestDataProvidersFullRefresh(); |
| |
| boolean controllerIsLeader; |
| |
| if (changeContext == null || changeContext.getType() == NotificationContext.Type.FINALIZE) { |
| logger.info( |
| "GenericClusterController.onControllerChange() Cluster change type {} for cluster {}. Disable leadership.", |
| changeContext == null ? null : changeContext.getType(), _clusterName); |
| controllerIsLeader = false; |
| } else { |
| // double check if this controller is the leader |
| controllerIsLeader = changeContext.getManager().isLeader(); |
| } |
| |
| if (controllerIsLeader) { |
| HelixManager manager = changeContext.getManager(); |
| HelixDataAccessor accessor = manager.getHelixDataAccessor(); |
| Builder keyBuilder = accessor.keyBuilder(); |
| PauseSignal pauseSignal = accessor.getProperty(keyBuilder.pause()); |
| MaintenanceSignal maintenanceSignal = accessor.getProperty(keyBuilder.maintenance()); |
| _paused = updateControllerState(changeContext, pauseSignal, _paused); |
| _inMaintenanceMode = |
| updateControllerState(changeContext, maintenanceSignal, _inMaintenanceMode); |
| enableClusterStatusMonitor(true); |
| _clusterStatusMonitor.setEnabled(!_paused); |
| _clusterStatusMonitor.setPaused(_paused); |
| _clusterStatusMonitor.setMaintenance(_inMaintenanceMode); |
| } else { |
| enableClusterStatusMonitor(false); |
| // Note that onControllerChange is executed in parallel with the event processing thread. It |
| // is possible that the current WAGED rebalancer object is in use for handling callback. So |
| // mark the rebalancer invalid only, instead of closing it here. |
| // This to-be-closed WAGED rebalancer will be reset later on a later event processing if |
| // the controller becomes leader again. |
| _rebalancerRef.invalidateRebalancer(); |
| } |
| |
| logger.info("END: GenericClusterController.onControllerChange() for cluster " + _clusterName); |
| } |
| |
| /** |
| * Go through the list of liveinstances in the cluster, and add currentstateChange listener and |
| * Message listeners to them if they are newly added. For current state change, the observation is |
| * tied to the session id of each live instance. |
| */ |
| protected void checkLiveInstancesObservation(List<LiveInstance> liveInstances, |
| NotificationContext changeContext) { |
| |
| // construct maps for current live-instances |
| Map<String, LiveInstance> curInstances = new HashMap<>(); |
| Map<String, LiveInstance> curSessions = new HashMap<>(); |
| for (LiveInstance liveInstance : liveInstances) { |
| curInstances.put(liveInstance.getInstanceName(), liveInstance); |
| curSessions.put(liveInstance.getEphemeralOwner(), liveInstance); |
| } |
| |
| // TODO: remove the synchronization here once we move this update into dataCache. |
| synchronized (_lastSeenInstances) { |
| Map<String, LiveInstance> lastInstances = _lastSeenInstances.get(); |
| Map<String, LiveInstance> lastSessions = _lastSeenSessions.get(); |
| |
| HelixManager manager = changeContext.getManager(); |
| Builder keyBuilder = new Builder(manager.getClusterName()); |
| if (lastSessions != null) { |
| for (String session : lastSessions.keySet()) { |
| if (!curSessions.containsKey(session)) { |
| // remove current-state listener for expired session |
| String instanceName = lastSessions.get(session).getInstanceName(); |
| manager.removeListener(keyBuilder.currentStates(instanceName, session), this); |
| } |
| } |
| } |
| |
| if (lastInstances != null) { |
| for (String instance : lastInstances.keySet()) { |
| if (!curInstances.containsKey(instance)) { |
| // remove message listener for disconnected instances |
| manager.removeListener(keyBuilder.messages(instance), this); |
| } |
| } |
| } |
| |
| for (String session : curSessions.keySet()) { |
| if (lastSessions == null || !lastSessions.containsKey(session)) { |
| String instanceName = curSessions.get(session).getInstanceName(); |
| try { |
| // add current-state listeners for new sessions |
| manager.addCurrentStateChangeListener(this, instanceName, session); |
| logger.info(manager.getInstanceName() + " added current-state listener for instance: " |
| + instanceName + ", session: " + session + ", listener: " + this); |
| } catch (Exception e) { |
| logger.error("Fail to add current state listener for instance: " + instanceName |
| + " with session: " + session, e); |
| } |
| } |
| } |
| |
| for (String instance : curInstances.keySet()) { |
| if (lastInstances == null || !lastInstances.containsKey(instance)) { |
| try { |
| // add message listeners for new instances |
| manager.addMessageListener(this, instance); |
| logger.info(manager.getInstanceName() + " added message listener for " + instance |
| + ", listener: " + this); |
| } catch (Exception e) { |
| logger.error("Fail to add message listener for instance: " + instance, e); |
| } |
| } |
| } |
| |
| // update last-seen |
| _lastSeenInstances.set(curInstances); |
| _lastSeenSessions.set(curSessions); |
| } |
| } |
| |
| public void shutdown() throws InterruptedException { |
| stopPeriodRebalance(); |
| |
| logger.info("Shutting down {} pipeline", Pipeline.Type.DEFAULT.name()); |
| shutdownPipeline(_eventThread, _eventQueue); |
| |
| logger.info("Shutting down {} pipeline", Pipeline.Type.TASK.name()); |
| shutdownPipeline(_taskEventThread, _taskEventQueue); |
| |
| // shutdown asycTasksThreadpool and wait for terminate. |
| _asyncTasksThreadPool.shutdownNow(); |
| try { |
| _asyncTasksThreadPool.awaitTermination(EVENT_THREAD_JOIN_TIMEOUT, TimeUnit.MILLISECONDS); |
| } catch (InterruptedException ex) { |
| logger.warn("Timeout when terminating async tasks. Some async tasks are still executing."); |
| } |
| |
| // shutdown async workers |
| shutdownAsyncFIFOWorkers(); |
| |
| enableClusterStatusMonitor(false); |
| |
| _rebalancerRef.closeRebalancer(); |
| |
| // TODO controller shouldn't be used in anyway after shutdown. |
| // Need to record shutdown and throw Exception if the controller is used again. |
| } |
| |
| private void enableClusterStatusMonitor(boolean enable) { |
| synchronized (_clusterStatusMonitor) { |
| if (_isMonitoring != enable) { |
| // monitoring state changed |
| if (enable) { |
| logger.info("Enable clusterStatusMonitor for cluster " + _clusterName); |
| // Clear old cached monitoring related data to avoid reporting stats cross different |
| // leadership periods |
| if (_resourceControlDataProvider != null) { |
| _resourceControlDataProvider.clearMonitoringRecords(); |
| } |
| _clusterStatusMonitor.active(); |
| } else { |
| logger.info("Disable clusterStatusMonitor for cluster " + _clusterName); |
| // Reset will be done if (_isMonitoring = false) later, no matter if the state is changed or not. |
| } |
| _isMonitoring = enable; |
| } |
| // Due to multithreads processing, async thread may write to monitor even it is closed. |
| // So when it is disabled, always try to clear the monitor. |
| resetClusterStatusMonitor(); |
| } |
| } |
| |
| private void resetClusterStatusMonitor() { |
| synchronized (_clusterStatusMonitor) { |
| if (!_isMonitoring) { |
| _clusterStatusMonitor.reset(); |
| } |
| } |
| } |
| |
| private void shutdownPipeline(Thread thread, ClusterEventBlockingQueue queue) |
| throws InterruptedException { |
| if (queue != null) { |
| queue.clear(); |
| } |
| |
| if (thread != null) { |
| while (thread.isAlive()) { |
| thread.interrupt(); |
| thread.join(EVENT_THREAD_JOIN_TIMEOUT); |
| } |
| } |
| } |
| |
| private boolean updateControllerState(NotificationContext changeContext, PauseSignal signal, |
| boolean statusFlag) { |
| if (signal != null) { |
| // This logic is used for recording first time entering PAUSE/MAINTENCE mode |
| if (!statusFlag) { |
| statusFlag = true; |
| logger.info(String.format("controller is now %s", |
| (signal instanceof MaintenanceSignal) ? "in maintenance mode" : "paused")); |
| } |
| } else { |
| if (statusFlag) { |
| statusFlag = false; |
| logger.info("controller is now resumed from paused state"); |
| String uid = UUID.randomUUID().toString().substring(0, 8); |
| ClusterEvent event = new ClusterEvent(_clusterName, ClusterEventType.Resume, |
| String.format("%s_%s", uid, Pipeline.Type.DEFAULT.name())); |
| event.addAttribute(AttributeName.changeContext.name(), changeContext); |
| event.addAttribute(AttributeName.helixmanager.name(), changeContext.getManager()); |
| event.addAttribute(AttributeName.AsyncFIFOWorkerPool.name(), _asyncFIFOWorkerPool); |
| enqueueEvent(_eventQueue, event); |
| enqueueEvent(_taskEventQueue, |
| event.clone(String.format("%s_%s", uid, Pipeline.Type.TASK.name()))); |
| } |
| } |
| return statusFlag; |
| } |
| |
| // TODO: refactor this to use common/ClusterEventProcessor. |
| @Deprecated |
| private class ClusterEventProcessor extends Thread { |
| private final BaseControllerDataProvider _cache; |
| private final ClusterEventBlockingQueue _eventBlockingQueue; |
| private final String _processorName; |
| |
| ClusterEventProcessor(BaseControllerDataProvider cache, |
| ClusterEventBlockingQueue eventBlockingQueue, String processorName) { |
| _cache = cache; |
| _eventBlockingQueue = eventBlockingQueue; |
| _processorName = processorName; |
| } |
| |
| @Override |
| public void run() { |
| logger.info( |
| "START ClusterEventProcessor thread for cluster " + _clusterName + ", processor name: " |
| + _processorName); |
| while (!isInterrupted()) { |
| try { |
| ClusterEvent newClusterEvent = _eventBlockingQueue.take(); |
| String threadName = String.format( |
| "HelixController-pipeline-%s-(%s)", _processorName, newClusterEvent.getEventId()); |
| this.setName(threadName); |
| handleEvent(newClusterEvent, _cache); |
| } catch (InterruptedException e) { |
| logger.warn("ClusterEventProcessor interrupted " + _processorName, e); |
| interrupt(); |
| } catch (ZkInterruptedException e) { |
| logger |
| .warn("ClusterEventProcessor caught a ZK connection interrupt " + _processorName, e); |
| interrupt(); |
| } catch (ThreadDeath death) { |
| logger.error("ClusterEventProcessor caught a ThreadDeath " + _processorName, death); |
| throw death; |
| } catch (Throwable t) { |
| logger.error("ClusterEventProcessor failed while running the controller pipeline " |
| + _processorName, t); |
| } |
| } |
| logger.info("END ClusterEventProcessor thread " + _processorName); |
| } |
| } |
| |
| private void initPipeline(Thread eventThread, BaseControllerDataProvider cache) { |
| if (eventThread == null || cache == null) { |
| logger.warn("pipeline cannot be initialized"); |
| return; |
| } |
| cache.setAsyncTasksThreadPool(_asyncTasksThreadPool); |
| |
| eventThread.setDaemon(true); |
| eventThread.start(); |
| } |
| |
| /** |
| * A wrapper class for the stateful rebalancer instance that will be tracked in the |
| * GenericHelixController. |
| */ |
| private abstract class StatefulRebalancerRef<T extends StatefulRebalancer> { |
| private T _rebalancer = null; |
| private boolean _isRebalancerValid = true; |
| |
| /** |
| * @param helixManager |
| * @return A new stateful rebalancer instance with initial state. |
| */ |
| protected abstract T createRebalancer(HelixManager helixManager); |
| |
| /** |
| * Mark the current rebalancer object to be invalid, which indicates it needs to be reset before |
| * the next usage. |
| */ |
| synchronized void invalidateRebalancer() { |
| _isRebalancerValid = false; |
| } |
| |
| /** |
| * @return A valid rebalancer object. |
| * If the rebalancer is no longer valid, it will be reset before returning. |
| * TODO: Make rebalancer volatile or make it singleton, if this method is called in multiple |
| * TODO: threads outside the controller object. |
| */ |
| synchronized T getRebalancer(HelixManager helixManager) { |
| // Lazily initialize the stateful rebalancer instance since the GenericHelixController |
| // instance is instantiated without the HelixManager information that is required. |
| if (_rebalancer == null) { |
| _rebalancer = createRebalancer(helixManager); |
| _isRebalancerValid = true; |
| } |
| // If the rebalance exists but has been marked as invalid (due to leadership switch), it needs |
| // to be reset before return. |
| if (!_isRebalancerValid) { |
| _rebalancer.reset(); |
| _isRebalancerValid = true; |
| } |
| return _rebalancer; |
| } |
| |
| /** |
| * Proactively close the rebalance object to release the resources. |
| */ |
| synchronized void closeRebalancer() { |
| if (_rebalancer != null) { |
| _rebalancer.close(); |
| _rebalancer = null; |
| } |
| } |
| } |
| } |
