SaurabhChawla100 commented on a change in pull request #27636: [SPARK-30873][CORE][YARN]Handling Node Decommissioning for Yarn cluster manger in Spark URL: https://github.com/apache/spark/pull/27636#discussion_r392683228
########## File path: core/src/main/scala/org/apache/spark/scheduler/DecommissionTracker.scala ########## @@ -0,0 +1,405 @@ +/* + * 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.text.SimpleDateFormat +import java.util.concurrent.TimeUnit +import java.util.concurrent.atomic.{AtomicBoolean, AtomicInteger} + +import scala.collection.mutable.HashMap + +import org.apache.spark.{ExecutorAllocationClient, SparkConf, SparkContext} +import org.apache.spark.annotation.DeveloperApi +import org.apache.spark.internal.Logging +import org.apache.spark.internal.config +import org.apache.spark.util.{Clock, SystemClock, ThreadUtils, Utils} + +/** + * DecommissionTracker tracks the list of decommissioned nodes. + * This decommission trackers maintains the decommissioned nodes state. + * Decommission tracker schedules the executor decommission and shuffle + * decommission for that node. + */ +private[scheduler] class DecommissionTracker ( + conf: SparkConf, + executorAllocClient: Option[ExecutorAllocationClient], + dagScheduler: Option[DAGScheduler], + clock: Clock = new SystemClock()) extends Logging { + + def this(sc: SparkContext, + client: Option[ExecutorAllocationClient], + dagScheduler: Option[DAGScheduler]) = { + this(sc.conf, client, dagScheduler) + } + + // Decommission thread of node decommissioning!! + private val decommissionThread = + ThreadUtils.newDaemonThreadPoolScheduledExecutor("node-decommissioning-thread", 20) + + // Contains workers hostname which are decommissioning. Added when spot-loss or + // graceful decommissioning event arrives from the AM. And is removed when the + // last node (identified by nodeId) is running again. + private val decommissionHostnameMap = new HashMap[String, NodeDecommissionInfo] + + private val minDecommissionTime = + conf.get(config.GRACEFUL_DECOMMISSION_MIN_TERMINATION_TIME_IN_SEC) + + private val executorDecommissionLeasePct = + conf.get(config.GRACEFUL_DECOMMISSION_EXECUTOR_LEASETIME_PCT) + + private val shuffleDataDecommissionLeasePct = + conf.get(config.GRACEFUL_DECOMMISSION_SHUFFLEDATA_LEASETIME_PCT) + + /* + * Is the node decommissioned i.e from driver point of + * view the node is considered decommissioned. + */ + def isNodeDecommissioned(hostname: String): Boolean = synchronized { + decommissionHostnameMap.get(hostname) match { + case None => false + case Some(info) => + return info.state == NodeDecommissionState.SHUFFLEDATA_DECOMMISSIONED || + info.state == NodeDecommissionState.TERMINATED + } + } + + /* + * Is the node decommissioning i.e from driver point of + * view the node is candidate for decommissioning. + * Not necessarily decommissioned or terminated + */ + def isNodeDecommissioning(hostname: String): Boolean = synchronized { + decommissionHostnameMap.contains(hostname) Review comment: isNodeDecommissioning is used when we are registering the new executor on particular node and also when we are making offer of task to the particular executor , In both those scenarios if the node is there in the decommission tracker than we don't do the above jobs. So there is no need to check the state here. Also we are changing the state in the decommission tracker.So there is no need to check the state here This is the life cycle of the nodes which is decommissioned DECOMMISSIONING -> EXECUTOR_DECOMMISSIONED -> SHUFFLEDATA_DECOMMISSIONED -> TERMINATED. So for all the state we don't have to register any new executor on that node and neither to assign any new task to that existing executor on that node. ---------------------------------------------------------------- This is an automated message from the Apache Git Service. To respond to the message, please log on to GitHub and use the URL above to go to the specific comment. For queries about this service, please contact Infrastructure at: [email protected] With regards, Apache Git Services --------------------------------------------------------------------- To unsubscribe, e-mail: [email protected] For additional commands, e-mail: [email protected]
