tgravescs commented on a change in pull request #29906: URL: https://github.com/apache/spark/pull/29906#discussion_r501029076
########## File path: core/src/main/scala/org/apache/spark/scheduler/HealthTracker.scala ########## @@ -0,0 +1,478 @@ +/* + * 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.spark.scheduler + +import java.util.concurrent.atomic.AtomicReference + +import scala.collection.mutable.{ArrayBuffer, HashMap, HashSet} + +import org.apache.spark.{ExecutorAllocationClient, SparkConf, SparkContext} +import org.apache.spark.internal.Logging +import org.apache.spark.internal.config +import org.apache.spark.util.{Clock, SystemClock, Utils} + +/** + * HealthTracker is designed to track problematic executors and nodes. It supports excluding + * executors and nodes across an entire application (with a periodic expiry). TaskSetManagers add + * additional logic for exclusion of executors and nodes for individual tasks and stages which + * works in concert with the logic here. + * + * The tracker needs to deal with a variety of workloads, eg.: + * + * * bad user code -- this may lead to many task failures, but that should not count against + * individual executors + * * many small stages -- this may prevent a bad executor for having many failures within one + * stage, but still many failures over the entire application + * * "flaky" executors -- they don't fail every task, but are still faulty enough to merit + * excluding + * + * See the design doc on SPARK-8425 for a more in-depth discussion. + * + * THREADING: As with most helpers of TaskSchedulerImpl, this is not thread-safe. Though it is + * called by multiple threads, callers must already have a lock on the TaskSchedulerImpl. The + * one exception is [[excludedNodeList()]], which can be called without holding a lock. + */ +private[scheduler] class HealthTracker ( + private val listenerBus: LiveListenerBus, + conf: SparkConf, + allocationClient: Option[ExecutorAllocationClient], + clock: Clock = new SystemClock()) extends Logging { + + def this(sc: SparkContext, allocationClient: Option[ExecutorAllocationClient]) = { + this(sc.listenerBus, sc.conf, allocationClient) + } + + HealthTracker.validateExcludeOnFailureConfs(conf) + private val MAX_FAILURES_PER_EXEC = conf.get(config.MAX_FAILURES_PER_EXEC) + private val MAX_FAILED_EXEC_PER_NODE = conf.get(config.MAX_FAILED_EXEC_PER_NODE) + val EXCLUDE_ON_FAILURE_TIMEOUT_MILLIS = HealthTracker.getExludeOnFailureTimeout(conf) + private val EXCLUDE_FETCH_FAILURE_ENABLED = + conf.get(config.EXCLUDE_ON_FAILURE_FETCH_FAILURE_ENABLED) + + /** + * A map from executorId to information on task failures. Tracks the time of each task failure, + * so that we can avoid excluding executors due to failures that are very far apart. We do not + * actively remove from this as soon as tasks hit their timeouts, to avoid the time it would take + * to do so. But it will not grow too large, because as soon as an executor gets too many + * failures, we exclude the executor and remove its entry here. + */ + private val executorIdToFailureList = new HashMap[String, ExecutorFailureList]() + val executorIdToExcludedStatus = new HashMap[String, ExcludedExecutor]() + val nodeIdToExcludedExpiryTime = new HashMap[String, Long]() + /** + * An immutable copy of the set of nodes that are currently excluded. Kept in an + * AtomicReference to make [[excludedNodeList()]] thread-safe. + */ + private val _excludedNodeList = new AtomicReference[Set[String]](Set()) + /** + * Time when the next excluded node will expire. Used as a shortcut to + * avoid iterating over all entries in the excludedNodeList when none will have expired. + */ + var nextExpiryTime: Long = Long.MaxValue + /** + * Mapping from nodes to all of the executors that have been excluded on that node. We do *not* + * remove from this when executors are removed from spark, so we can track when we get multiple + * successive excluded executors on one node. Nonetheless, it will not grow too large because + * there cannot be many excluded executors on one node, before we stop requesting more + * executors on that node, and we clean up the list of exluded executors once an executor has + * been excluded for EXCLUDE_ON_FAILURE_TIMEOUT_MILLIS. + */ + val nodeToExcludedExecs = new HashMap[String, HashSet[String]]() + + /** + * Include executors and nodes that have been excluded for at least + * EXCLUDE_ON_FAILURE_TIMEOUT_MILLIS + */ + def applyExcludeOnFailureTimeout(): Unit = { + val now = clock.getTimeMillis() + // quickly check if we've got anything to expire that is excluded -- if not, + // avoid doing any work + if (now > nextExpiryTime) { + // Apply the timeout to excluded nodes and executors + val execsToInclude = executorIdToExcludedStatus.filter(_._2.expiryTime < now).keys + if (execsToInclude.nonEmpty) { + // Include any executors that have been exluded longer than the excludeOnFailure timeout. + logInfo(s"Removing executors $execsToInclude from exclude list because the " + + s"the executors have reached the timed out") + execsToInclude.foreach { exec => + val status = executorIdToExcludedStatus.remove(exec).get + val failedExecsOnNode = nodeToExcludedExecs(status.node) + listenerBus.post(SparkListenerExecutorUnexcluded(now, exec)) + failedExecsOnNode.remove(exec) + if (failedExecsOnNode.isEmpty) { + nodeToExcludedExecs.remove(status.node) + } + } + } + val nodesToInclude = nodeIdToExcludedExpiryTime.filter(_._2 < now).keys + if (nodesToInclude.nonEmpty) { + // Include any nodes that have been excluded longer than the excludeOnFailure timeout. + logInfo(s"Removing nodes $nodesToInclude from exclude list because the " + + s"nodes have reached has timed out") + nodesToInclude.foreach { node => + nodeIdToExcludedExpiryTime.remove(node) + listenerBus.post(SparkListenerNodeUnexcluded(now, node)) + } + _excludedNodeList.set(nodeIdToExcludedExpiryTime.keySet.toSet) + } + updateNextExpiryTime() + } + } + + private def updateNextExpiryTime(): Unit = { + val execMinExpiry = if (executorIdToExcludedStatus.nonEmpty) { + executorIdToExcludedStatus.map{_._2.expiryTime}.min + } else { + Long.MaxValue + } + val nodeMinExpiry = if (nodeIdToExcludedExpiryTime.nonEmpty) { + nodeIdToExcludedExpiryTime.values.min + } else { + Long.MaxValue + } + nextExpiryTime = math.min(execMinExpiry, nodeMinExpiry) + } + + private def killExecutor(exec: String, msg: String): Unit = { + allocationClient match { + case Some(a) => + logInfo(msg) + a.killExecutors(Seq(exec), adjustTargetNumExecutors = false, countFailures = false, + force = true) + case None => + logInfo(s"Not attempting to kill excluded executor id $exec " + + s"since allocation client is not defined.") + } + } + + private def killExcludedExecutor(exec: String): Unit = { + if (conf.get(config.EXCLUDE_ON_FAILURE_KILL_ENABLED)) { + killExecutor(exec, s"Killing excluded executor id $exec since " + + s"${config.EXCLUDE_ON_FAILURE_KILL_ENABLED.key} is set.") + } + } + + private[scheduler] def killExcludedIdleExecutor(exec: String): Unit = { + killExecutor(exec, + s"Killing excluded idle executor id $exec because of task unschedulability and trying " + + "to acquire a new executor.") + } + + private def killExecutorsOnExcludedNode(node: String): Unit = { + if (conf.get(config.EXCLUDE_ON_FAILURE_KILL_ENABLED)) { + allocationClient match { + case Some(a) => + logInfo(s"Killing all executors on excluded host $node " + + s"since ${config.EXCLUDE_ON_FAILURE_KILL_ENABLED.key} is set.") + if (a.killExecutorsOnHost(node) == false) { + logError(s"Killing executors on node $node failed.") + } + case None => + logWarning(s"Not attempting to kill executors on excluded host $node " + + s"since allocation client is not defined.") + } + } + } + + def updateExcludedForFetchFailure(host: String, exec: String): Unit = { + if (EXCLUDE_FETCH_FAILURE_ENABLED) { + // If we exclude on fetch failures, we are implicitly saying that we believe the failure is + // non-transient, and can't be recovered from (even if this is the first fetch failure, + // stage is retried after just one failure, so we don't always get a chance to collect + // multiple fetch failures). + // If the external shuffle-service is on, then every other executor on this node would + // be suffering from the same issue, so we should exclude (and potentially kill) all + // of them immediately. + + val now = clock.getTimeMillis() + val expiryTimeForNewExcludes = now + EXCLUDE_ON_FAILURE_TIMEOUT_MILLIS + + if (conf.get(config.SHUFFLE_SERVICE_ENABLED)) { + if (!nodeIdToExcludedExpiryTime.contains(host)) { + logInfo(s"excluding node $host due to fetch failure of external shuffle service") + + nodeIdToExcludedExpiryTime.put(host, expiryTimeForNewExcludes) + listenerBus.post(SparkListenerNodeExcluded(now, host, 1)) + _excludedNodeList.set(nodeIdToExcludedExpiryTime.keySet.toSet) + killExecutorsOnExcludedNode(host) + updateNextExpiryTime() + } + } else if (!executorIdToExcludedStatus.contains(exec)) { + logInfo(s"Excluding executor $exec due to fetch failure") + + executorIdToExcludedStatus.put(exec, ExcludedExecutor(host, expiryTimeForNewExcludes)) + // We hardcoded number of failure tasks to 1 for fetch failure, because there's no + // reattempt for such failure. + listenerBus.post(SparkListenerExecutorExcluded(now, exec, 1)) Review comment: sounds good, I'll move the handling to OnOtherEvent ---------------------------------------------------------------- This is an automated message from the Apache Git Service. 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