Github user squito commented on a diff in the pull request:
https://github.com/apache/spark/pull/8760#discussion_r45755581
--- Diff:
core/src/main/scala/org/apache/spark/scheduler/BlacklistTracker.scala ---
@@ -0,0 +1,247 @@
+/*
+ * 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.TimeUnit
+import scala.collection.mutable
+import org.apache.spark.SparkConf
+import org.apache.spark.Success
+import org.apache.spark.TaskEndReason
+import org.apache.spark.annotation.DeveloperApi
+import org.apache.spark.util.SystemClock
+import org.apache.spark.util.ThreadUtils
+import org.apache.spark.util.Utils
+import org.apache.spark.util.Clock
+
+import com.google.common.annotations.VisibleForTesting
+
+/**
+ * BlacklistTracker is design to track problematic executors and node on
application level.
+ * It is shared by all TaskSet, so that once a new TaskSet coming, it
could be benefit from
+ * previous experience of other TaskSet.
+ *
+ * Once task finished, the callback method in TaskSetManager should update
+ * executorIdToFailureStatus Map.
+ */
+private[spark] class BlacklistTracker(
+ sparkConf: SparkConf,
+ clock: Clock = new SystemClock()) extends BlacklistCache{
+ // maintain a ExecutorId --> FailureStatus HashMap
+ private val executorIdToFailureStatus: mutable.HashMap[String,
FailureStatus] = mutable.HashMap()
+
+ // Apply Strategy pattern here to change different blacklist detection
logic
+ private val strategy = BlacklistStrategy(sparkConf)
+
+ // A daemon thread to expire blacklist executor periodically
+ private val scheduler =
ThreadUtils.newDaemonSingleThreadScheduledExecutor(
+ "spark-scheduler-blacklist-expire-timer")
+
+ private val recoverPeriod = sparkConf.getTimeAsSeconds(
+ "spark.scheduler.blacklist.recoverPeriod", "60s")
+
+ def start(): Unit = {
+ val scheduleTask = new Runnable() {
+ override def run(): Unit = {
+ Utils.logUncaughtExceptions(expireExecutorsInBlackList())
+ }
+ }
+ scheduler.scheduleAtFixedRate(scheduleTask, 0L, recoverPeriod,
TimeUnit.SECONDS)
+ }
+
+ def stop(): Unit = {
+ scheduler.shutdown()
+ scheduler.awaitTermination(10, TimeUnit.SECONDS)
+ }
+
+ // The actual implementation is delegated to strategy
+ /** VisibleForTesting */
+ private[scheduler] def expireExecutorsInBlackList(): Unit = synchronized
{
+ val updated =
strategy.expireExecutorsInBlackList(executorIdToFailureStatus, clock)
+ if (updated) {
+ invalidAllCache()
+ }
+ }
+
+ def updateFailureExecutors(
+ stageId: Int, info: TaskInfo, reason: TaskEndReason) : Unit =
synchronized {
+ val index = info.index
+ val atomTask = BlacklistAtomTask(stageId, index)
+ reason match {
+ // If task succeeding, remove related record from
executorIdToFailureStatus
+ case Success =>
+ removeFailureExecutorsForTaskId(info.executorId, stageId, index)
+
+ // If task failing, update latest failure time and failedTaskIds
+ case _ =>
+ val executorId = info.executorId
+ executorIdToFailureStatus.get(executorId) match {
+ case Some(failureStatus) =>
+ failureStatus.updatedTime = clock.getTimeMillis()
+ val failedTimes =
failureStatus.numFailuresPerTask.getOrElse(atomTask, 0) + 1
+ failureStatus.numFailuresPerTask.update(atomTask, failedTimes)
+ case None =>
+ val failedTasks = mutable.HashMap(atomTask -> 1)
+ val failureStatus = new FailureStatus(
+ clock.getTimeMillis(), info.host, failedTasks)
+ executorIdToFailureStatus.update(executorId, failureStatus)
+ }
+ invalidAllCache()
+ }
+ }
+
+ /** remove the executorId from executorIdToFailureStatus */
+ def removeFailureExecutors(executorId: String) : Unit = synchronized {
+ executorIdToFailureStatus.remove(executorId)
+ invalidAllCache()
+ }
+
+ /**
+ * remove the failure record related to given taskId from
executorIdToFailureStatus. If the
+ * number of records of given executorId becomes 0, remove the completed
executorId.
+ */
+ def removeFailureExecutorsForTaskId(
+ executorId: String,
+ stageId: Int,
+ taskIndex: Int) : Unit = synchronized {
+ val atomTask = BlacklistAtomTask(stageId, taskIndex)
+ executorIdToFailureStatus.get(executorId).map(fs => {
+ fs.numFailuresPerTask.remove(atomTask)
+ if(fs.numFailuresPerTask.isEmpty){
+ executorIdToFailureStatus.remove(executorId)
+ }
+ invalidAllCache()
+ })
+ }
+
+ def executorIsBlacklisted(
+ executorId: String,
+ sched: TaskSchedulerImpl,
+ stageId: Int,
+ taskIndex: Int) : Boolean = {
+
+ executorBlacklist(sched, stageId, taskIndex).contains(executorId)
+ }
+
+ // If the node is in blacklist, all executors allocated on that node will
+ // also be put into executor blacklist.
+ private def executorsOnBlacklistedNode(
+ sched: TaskSchedulerImpl): Set[String] = {
+ nodeBlacklist().flatMap(sched.getExecutorsAliveOnHost(_)
+ .getOrElse(Set.empty[String])).toSet
+ }
+
+ def executorBlacklist(
+ sched: TaskSchedulerImpl, stageId: Int, taskIndex: Int): Set[String]
= synchronized {
+ val atomTask = BlacklistAtomTask(stageId, taskIndex)
+ if (!isBlacklistExecutorCacheValid) {
+ reEvaluateExecutorBlacklistAndUpdateCache(sched, atomTask, clock)
+ } else {
+ getExecutorBlacklistFromCache(atomTask).getOrElse {
+ reEvaluateExecutorBlacklistAndUpdateCache(sched, atomTask, clock)
+ }
+ }
+ }
+
+ private def reEvaluateExecutorBlacklistAndUpdateCache(
+ sched: TaskSchedulerImpl,
+ atomTask: BlacklistAtomTask,
+ clock: Clock): Set[String] = {
+ val executors = executorsOnBlacklistedNode(sched) ++
+ strategy.getExecutorBlacklist(executorIdToFailureStatus, atomTask,
clock)
+ updateBlacklistExecutorCache(atomTask, executors)
+ executors
+ }
+
+ // The actual implementation is delegated to strategy
+ def nodeBlacklist(): Set[String] = synchronized {
+ if (isBlacklistNodeCacheValid) {
+ getNodeBlacklistFromCache
+ } else {
+ val nodes = strategy.getNodeBlacklist(executorIdToFailureStatus)
+ updateBlacklistNodeCache(nodes)
+ nodes
+ }
+ }
+}
+
+/**
+ * Hide cache details in this trait to make code clean and avoid operation
mistake
+ */
+private[scheduler] trait BlacklistCache {
+
+ // local cache to minimize the the work when query blacklisted executor
and node
+ private val blacklistExecutorCache =
mutable.HashMap.empty[BlacklistAtomTask, Set[String]]
+ private val blacklistNodeCache = mutable.Set.empty[String]
+
+ // The flag to mark if cache is valid, it will be set to false when
executorIdToFailureStatus be
+ // updated and it will be set to true, when called executorBlacklist and
nodeBlacklist.
+ private var _isBlacklistExecutorCacheValid : Boolean = false
+ private var _isBlacklistNodeCacheValid: Boolean = false
+
+ private val cacheLock = new Object()
+
+ protected def isBlacklistExecutorCacheValid : Boolean =
_isBlacklistExecutorCacheValid
+ protected def isBlacklistNodeCacheValid: Boolean =
_isBlacklistNodeCacheValid
+
+ protected def updateBlacklistExecutorCache(
+ atomTask: BlacklistAtomTask,
+ blacklistExecutor: Set[String]): Unit = cacheLock.synchronized {
+ if (!_isBlacklistExecutorCacheValid) {
+ blacklistExecutorCache.clear()
+ }
+ blacklistExecutorCache.update(atomTask, blacklistExecutor)
+ _isBlacklistExecutorCacheValid = true
+ }
+
+ protected def updateBlacklistNodeCache(
+ blacklistNode: Set[String]): Unit = cacheLock.synchronized {
+ if (!_isBlacklistNodeCacheValid) {
+ blacklistNodeCache.clear()
+ }
+ blacklistNodeCache ++= blacklistNode
+ _isBlacklistNodeCacheValid = true
+ }
+
+ protected def invalidAllCache(): Unit = cacheLock.synchronized {
+ _isBlacklistExecutorCacheValid = false
+ _isBlacklistNodeCacheValid = false
+ }
+
+ protected def getExecutorBlacklistFromCache(
+ atomTask: BlacklistAtomTask): Option[Set[String]] =
blacklistExecutorCache.get(atomTask)
+
+ protected def getNodeBlacklistFromCache: Set[String] =
blacklistNodeCache.toSet
+}
+/**
+ * A class to record details of failure.
+ *
+ * @param initialTime the time when failure status be created
+ * @param host the node name which running executor on
+ * @param numFailuresPerTask all tasks failed on the executor (key is
BlacklistAtomTask, value
+ * is the number of failures of this task)
+ */
+final class FailureStatus(
+ initialTime: Long,
+ val host: String,
+ val numFailuresPerTask: mutable.HashMap[BlacklistAtomTask, Int]) {
+
+ var updatedTime = initialTime
+ def totalNumFailures : Int = numFailuresPerTask.values.sum
+}
+
+case class BlacklistAtomTask(val stageId: Int, val taskIndex: Int)
--- End diff --
how about just renaming it `StageAndPartition`? also `private[scheduler]`
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