cmccabe commented on a change in pull request #10095: URL: https://github.com/apache/kafka/pull/10095#discussion_r573981156
########## File path: core/src/main/scala/kafka/server/BrokerLifecycleManager.scala ########## @@ -0,0 +1,457 @@ +/** + * 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 kafka.server + +import java.util +import java.util.concurrent.TimeUnit.{MILLISECONDS, NANOSECONDS} +import java.util.concurrent.{CompletableFuture, TimeUnit} +import kafka.utils.Logging +import org.apache.kafka.clients.ClientResponse +import org.apache.kafka.common.Uuid +import org.apache.kafka.common.message.BrokerRegistrationRequestData.ListenerCollection +import org.apache.kafka.common.message.{BrokerHeartbeatRequestData, BrokerRegistrationRequestData} +import org.apache.kafka.common.protocol.Errors +import org.apache.kafka.common.requests.{BrokerHeartbeatRequest, BrokerHeartbeatResponse, BrokerRegistrationRequest, BrokerRegistrationResponse} +import org.apache.kafka.metadata.{BrokerState, VersionRange} +import org.apache.kafka.queue.EventQueue.DeadlineFunction +import org.apache.kafka.common.utils.{ExponentialBackoff, LogContext, Time} +import org.apache.kafka.queue.{EventQueue, KafkaEventQueue} +import scala.jdk.CollectionConverters._ + + +class BrokerLifecycleManager(val config: KafkaConfig, + val time: Time, + val threadNamePrefix: Option[String]) extends Logging { + val logContext = new LogContext(s"[BrokerLifecycleManager id=${config.nodeId}] ") + + this.logIdent = logContext.logPrefix() + + /** + * The broker id. + */ + private val nodeId = config.nodeId + + /** + * The broker rack, or null if there is no configured rack. + */ + private val rack = config.rack.orNull + + /** + * How long to wait for registration to succeed before failing the startup process. + */ + private val initialTimeoutNs = NANOSECONDS. + convert(config.initialRegistrationTimeoutMs.longValue(), TimeUnit.MILLISECONDS) + + /** + * The exponential backoff to use for resending communication. + */ + private val resendExponentialBackoff = + new ExponentialBackoff(100, 2, config.brokerSessionTimeoutMs.toLong, 0.1) + + /** + * The number of tries we've tried to communicate. + */ + private var failedAttempts = 0L + + /** + * The broker incarnation ID. This ID uniquely identifies each time we start the broker + */ + val incarnationId = Uuid.randomUuid() + + /** + * A future which is completed just as soon as the broker has caught up with the latest + * metadata offset for the first time. + */ + val initialCatchUpFuture = new CompletableFuture[Void]() + + /** + * A future which is completed when controlled shutdown is done. + */ + val controlledShutdownFuture = new CompletableFuture[Void]() + + /** + * The broker epoch, or -1 if the broker has not yet registered. + * This variable can only be written from the event queue thread. + */ + @volatile private var _brokerEpoch = -1L + + /** + * The current broker state. + * This variable can only be written from the event queue thread. + */ + @volatile private var _state = BrokerState.NOT_RUNNING + + /** + * A callback function which gives this manager the current highest metadata offset. + * This function must be thread-safe. + */ + private var _highestMetadataOffsetProvider: () => Long = null + + /** + * True only if we are ready to unfence the broker. + * This variable can only be accessed from the event queue thread. + */ + private var readyToUnfence = false + + /** + * True if we sent a heartbeat to the active controller requesting controlled + * shutdown. + */ + private var gotControlledShutdownResponse = false + + /** + * Whether or not we this broker is registered with the controller quorum. + * This variable can only be accessed from the event queue thread. + */ + private var registered = false + + /** + * True if the initial registration succeeded. + * This variable can only be accessed from the event queue thread. + */ + private var initialRegistrationSucceeded = false + + /** + * The cluster ID, or null if this manager has not been started yet. + * This variable can only be accessed from the event queue thread. + */ + private var _clusterId: Uuid = null + + /** + * The listeners which this broker advertises. + */ + private var _advertisedListeners: ListenerCollection = null + + /** + * The features supported by this broker. + */ + private var _supportedFeatures: util.Map[String, VersionRange] = null + + /** + * The channel manager, or null if this manager has not been started yet. + * This variable can only be accessed from the event queue thread. + */ + var _channelManager: BrokerToControllerChannelManager = null + + /** + * The event queue. + */ + val eventQueue = new KafkaEventQueue(time, logContext, threadNamePrefix.getOrElse("")) + + /** + * Start the BrokerLifecycleManager. + * + * @param highestMetadataOffsetProvider Provides the current highest metadata offset. + * @param channelManager The brokerToControllerChannelManager to use. + * @param clusterId The cluster ID. + */ + def start(highestMetadataOffsetProvider: () => Long, + channelManager: BrokerToControllerChannelManager, + clusterId: Uuid, + advertisedListeners: ListenerCollection, + supportedFeatures: util.Map[String, VersionRange]): Unit = { + eventQueue.append(new StartupEvent(highestMetadataOffsetProvider, + channelManager, clusterId, advertisedListeners, supportedFeatures)) + } + + def setReadyToUnfence(): Unit = { + eventQueue.append(new SetReadyToUnfenceEvent()) + } + + def brokerEpoch(): Long = _brokerEpoch + + def state(): BrokerState = _state + + class BeginControlledShutdownEvent extends EventQueue.Event { + override def run(): Unit = { + _state match { + case BrokerState.PENDING_CONTROLLED_SHUTDOWN => + info(s"Attempted to enter controlled shutdown state, but we are already in " + + s"that state.") + case BrokerState.RUNNING => + info(s"Beginning controlled shutdown.") + _state = BrokerState.PENDING_CONTROLLED_SHUTDOWN + case _ => + info(s"Skipping controlled shutdown because we are in state ${_state}.") + beginShutdown() + } + } + } + + /** + * Enter the controlled shutdown state if we are in RUNNING state. + * Or, if we're not running, shut down immediately. + */ + def beginControlledShutdown(): Unit = { + eventQueue.append(new BeginControlledShutdownEvent()) + } + + /** + * Start shutting down the BrokerLifecycleManager, but do not block. + */ + def beginShutdown(): Unit = { + eventQueue.beginShutdown("beginShutdown", new ShutdownEvent()) + } + + /** + * Shut down the BrokerLifecycleManager and block until all threads are joined. + */ + def close(): Unit = { + beginShutdown() + eventQueue.close() + } + + class SetReadyToUnfenceEvent() extends EventQueue.Event { + override def run(): Unit = { + readyToUnfence = true + scheduleNextCommunicationImmediately() + } + } + + class StartupEvent(highestMetadataOffsetProvider: () => Long, + channelManager: BrokerToControllerChannelManager, + clusterId: Uuid, + advertisedListeners: ListenerCollection, + supportedFeatures: util.Map[String, VersionRange]) extends EventQueue.Event { + override def run(): Unit = { + _highestMetadataOffsetProvider = highestMetadataOffsetProvider + _channelManager = channelManager + _channelManager.start() + _state = BrokerState.STARTING + _clusterId = clusterId + _advertisedListeners = advertisedListeners + _supportedFeatures = supportedFeatures + eventQueue.scheduleDeferred("initialRegistrationTimeout", + new DeadlineFunction(time.nanoseconds() + initialTimeoutNs), + new RegistrationTimeoutEvent()) + sendBrokerRegistration() + info(s"Incarnation ${incarnationId} of broker ${nodeId} in cluster ${clusterId} " + + "is now STARTING.") + } + } + + private def sendBrokerRegistration(): Unit = { + val features = new BrokerRegistrationRequestData.FeatureCollection() + _supportedFeatures.asScala.foreach { + case (name, range) => features.add(new BrokerRegistrationRequestData.Feature(). + setName(name). + setMinSupportedVersion(range.min()). + setMaxSupportedVersion(range.max())) + } + val data = new BrokerRegistrationRequestData(). + setBrokerId(nodeId). + setClusterId(_clusterId). + setFeatures(features). + setIncarnationId(incarnationId). + setListeners(_advertisedListeners). + setRack(rack) + if (isTraceEnabled) { + trace(s"Sending broker registration ${data}") + } + _channelManager.sendRequest(new BrokerRegistrationRequest.Builder(data), + new BrokerRegistrationResponseHandler()) + } + + class BrokerRegistrationResponseHandler extends ControllerRequestCompletionHandler { + override def onComplete(response: ClientResponse): Unit = { + if (response.authenticationException() != null) { + error(s"Unable to register broker ${nodeId} because of an authentication exception.", + response.authenticationException()); + scheduleNextCommunicationAfterFailure() + } else if (response.versionMismatch() != null) { + error(s"Unable to register broker ${nodeId} because of an API version problem.", + response.versionMismatch()); + scheduleNextCommunicationAfterFailure() + } else if (response.responseBody() == null) { + warn(s"Unable to register broker ${nodeId}.") + scheduleNextCommunicationAfterFailure() + } else if (!response.responseBody().isInstanceOf[BrokerRegistrationResponse]) { + error(s"Unable to register broker ${nodeId} because the controller returned an " + + "invalid response type.") + scheduleNextCommunicationAfterFailure() + } else { + val message = response.responseBody().asInstanceOf[BrokerRegistrationResponse] + val errorCode = Errors.forCode(message.data().errorCode()) + if (errorCode == Errors.NONE) { + failedAttempts = 0 + _brokerEpoch = message.data().brokerEpoch() + registered = true + initialRegistrationSucceeded = true + info(s"Successfully registered broker ${nodeId} with broker epoch ${_brokerEpoch}") + scheduleNextCommunicationImmediately() // Immediately send a heartbeat + } else { + info(s"Unable to register broker ${nodeId} because the controller returned " + + s"error ${errorCode}") + scheduleNextCommunicationAfterFailure() + } + } + } + + override def onTimeout(): Unit = { + info(s"Unable to register the broker because the RPC got timed out before it could be sent.") + scheduleNextCommunicationAfterFailure() + } + } + + private def sendBrokerHeartbeat(): Unit = { + val metadataOffset = _highestMetadataOffsetProvider() + val data = new BrokerHeartbeatRequestData(). + setBrokerEpoch(_brokerEpoch). + setBrokerId(nodeId). + setCurrentMetadataOffset(metadataOffset). + setWantFence(!readyToUnfence). + setWantShutDown(_state == BrokerState.PENDING_CONTROLLED_SHUTDOWN) + if (isTraceEnabled) { + trace(s"Sending broker heartbeat ${data}") + } + _channelManager.sendRequest(new BrokerHeartbeatRequest.Builder(data), + new BrokerHeartbeatResponseHandler()) + } + + class BrokerHeartbeatResponseHandler extends ControllerRequestCompletionHandler { + override def onComplete(response: ClientResponse): Unit = { + if (response.authenticationException() != null) { + error(s"Unable to send broker heartbeat for ${nodeId} because of an " + + "authentication exception.", response.authenticationException()); + scheduleNextCommunicationAfterFailure() + } else if (response.versionMismatch() != null) { + error(s"Unable to send broker heartbeat for ${nodeId} because of an API " + + "version problem.", response.versionMismatch()); + scheduleNextCommunicationAfterFailure() + } else if (response.responseBody() == null) { + warn(s"Unable to send broker heartbeat for ${nodeId}. Retrying.") + scheduleNextCommunicationAfterFailure() + } else if (!response.responseBody().isInstanceOf[BrokerHeartbeatResponse]) { + error(s"Unable to send broker heartbeat for ${nodeId} because the controller " + + "returned an invalid response type.") + scheduleNextCommunicationAfterFailure() + } else { + val message = response.responseBody().asInstanceOf[BrokerHeartbeatResponse] + val errorCode = Errors.forCode(message.data().errorCode()) + if (errorCode == Errors.NONE) { + failedAttempts = 0 + _state match { + case BrokerState.STARTING => + if (message.data().isCaughtUp()) { + info(s"The broker has caught up. Transitioning from STARTING to RECOVERY.") + _state = BrokerState.RECOVERY + initialCatchUpFuture.complete(null) + } else { + info(s"The broker is STARTING. Still waiting to catch up with cluster metadata.") + } + // Schedule the heartbeat after only 10 ms so that in the case where + //there is no recovery work to be done, we start up a bit quicker. + scheduleNextCommunication(NANOSECONDS.convert(10, MILLISECONDS)) + case BrokerState.RECOVERY => + if (!message.data().isFenced()) { + info(s"The broker has been unfenced. Transitioning from RECOVERY to RUNNING.") + _state = BrokerState.RUNNING + } else { + info(s"The broker is in RECOVERY.") + } + scheduleNextCommunicationAfterSuccess() + case BrokerState.RUNNING => + debug(s"The broker is RUNNING. Processing heartbeat response.") + scheduleNextCommunicationAfterSuccess() + case BrokerState.PENDING_CONTROLLED_SHUTDOWN => + if (!message.data().shouldShutDown()) { + info(s"The broker is in PENDING_CONTROLLED_SHUTDOWN state, still waiting " + + "for the active controller.") + if (!gotControlledShutdownResponse) { + // If this is the first pending controlled shutdown response we got, + // schedule our next heartbeat a little bit sooner than we usually would. + // In the case where controlled shutdown completes quickly, this will + // speed things up a little bit. + scheduleNextCommunication(NANOSECONDS.convert(50, MILLISECONDS)) + } else { + scheduleNextCommunicationAfterSuccess() + } + } else { + info(s"The controlled has asked us to exit controlled shutdown.") + beginShutdown() + } + gotControlledShutdownResponse = true + case BrokerState.SHUTTING_DOWN => + info(s"The broker is SHUTTING_DOWN. Ignoring heartbeat response.") + case _ => + error(s"Unexpected broker state ${_state}") + scheduleNextCommunicationAfterSuccess() + } + } else { + warn(s"Broker ${nodeId} sent a heartbeat request but received error ${errorCode}.") + scheduleNextCommunicationAfterFailure() + } + } + } + + override def onTimeout(): Unit = { + info("Unable to send a heartbeat because the RPC got timed out before it could be sent.") + scheduleNextCommunicationAfterFailure() + } + } + + private def scheduleNextCommunicationImmediately(): Unit = scheduleNextCommunication(0) + + private def scheduleNextCommunicationAfterFailure(): Unit = { + val delayMs = resendExponentialBackoff.backoff(failedAttempts) + failedAttempts = failedAttempts + 1 + scheduleNextCommunication(NANOSECONDS.convert(delayMs, MILLISECONDS)) + } + + private def scheduleNextCommunicationAfterSuccess(): Unit = { + scheduleNextCommunication(NANOSECONDS.convert( + config.brokerHeartbeatIntervalMs.longValue() , MILLISECONDS)) + } + + private def scheduleNextCommunication(intervalNs: Long): Unit = { + trace(s"Scheduling next communication at ${MILLISECONDS.convert(intervalNs, NANOSECONDS)} " + + "ms from now.") + val deadlineNs = time.nanoseconds() + intervalNs + eventQueue.scheduleDeferred("communication", + new DeadlineFunction(deadlineNs), + new CommunicationEvent()) + } + + class RegistrationTimeoutEvent extends EventQueue.Event { + override def run(): Unit = { + if (!initialRegistrationSucceeded) { + error("Shutting down because we were unable to register with the controller quorum.") + eventQueue.beginShutdown("registrationTimeout", new ShutdownEvent()) + } + } + } + + class CommunicationEvent extends EventQueue.Event { + override def run(): Unit = { + if (registered) { + sendBrokerHeartbeat() + } else { + sendBrokerRegistration() + } + } + } + + class ShutdownEvent extends EventQueue.Event { + override def run(): Unit = { + info(s"Transitioning from ${_state} to ${BrokerState.SHUTTING_DOWN}.") + _state = BrokerState.SHUTTING_DOWN + controlledShutdownFuture.complete(null) + initialCatchUpFuture.cancel(false) + _channelManager.shutdown() Review comment: good point. we should check. ---------------------------------------------------------------- This is an automated message from the Apache Git Service. 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