一、集群启动过程--启动Master
$SPARK_HOME/sbin/start-master.sh
start-master.sh脚本关键内容:
spark-daemon.sh start org.apache.spark.deploy.master.Master 1 --ip $SPARK_MASTER_IP --port $SPARK_MASTER_PORT --webui-port $SPARK_MASTER_WEBUI_PORT
日志信息:$SPARK_HOME/logs/
14/07/22 13:41:33 INFO Remoting: Remoting started; listening on addresses :[akka.tcp://[email protected]:7077] 14/07/22 13:41:33 INFO master.Master: Starting Spark master at spark://hadoop000:7077 14/07/22 13:41:33 INFO server.Server: jetty-8.y.z-SNAPSHOT 14/07/22 13:41:33 INFO server.AbstractConnector: Started [email protected]0.0.0.0:8080 14/07/22 13:41:33 INFO ui.MasterWebUI: Started MasterWebUI at http://hadoop000:8080 14/07/22 13:41:33 INFO master.Master: I have been elected leader! New state: ALIVE
二、集群启动过程--启动Worker
$SPARK_HOME/sbin/start-slaves.sh
start-slaves.sh脚本关键内容:
spark-daemon.sh start org.apache.spark.deploy.worker.Worker master-spark-URL
Worker运行时,需要注册到指定的master url,这里就是spark://hadoop000:7077
Worker启动之后主要做了两件事情:
1)将自己注册到Master(RegisterWorker);
2)定期发送心跳信息给Master;
Worker向Master发送注册信息:
Worker.scala ==>preStart ==>registerWithMaster ==>tryRegisterAllMasters ==> actor ! RegisterWorker(workerId, host, port, cores, memory, webUi.boundPort, publicAddress)
Master侧收到RegisterWorker通知:
Master.scala ==>case RegisterWorker(id, workerHost, workerPort, cores, memory, workerUiPort, publicAddress) => { val worker = new WorkerInfo(id, workerHost, workerPort, cores, memory, sender, workerUiPort, publicAddress) if (registerWorker(worker)) { persistenceEngine.addWorker(worker) sender ! RegisteredWorker(masterUrl, masterWebUiUrl) //注册成功后向Worker发送注册成功信息 schedule() } }
Worker在收到Master发来的注册成功信息后,定期向Master发送心跳信息
Worker.scala ==>case SendHeartbeat => masterLock.synchronized {if (connected) { master ! Heartbeat(workerId) } }
Master在接收到Worker发送来的心跳信息后更新最后一次心跳时间
Master.scala ==>case Heartbeat(workerId) => { idToWorker.get(workerId) match { case Some(workerInfo) => workerInfo.lastHeartbeat = System.currentTimeMillis() } }
Master定期移除超时未发送心跳信息给Master的Worker节点
Master.scala ==>preStart ==>CheckForWorkerTimeOut ==>case CheckForWorkerTimeOut => {timeOutDeadWorkers()} //Check for, and remove, any timed-out workers
日志信息:$SPARK_HOME/logs/
Master部分日志信息:
14/07/22 13:41:36 INFO master.Master: Registering worker hadoop000:48343 with 1 cores, 2.0 GB RAM
Worker部分日志信息:
14/07/22 13:41:35 INFO Worker: Starting Spark worker hadoop000:48343 with 1 cores, 2.0 GB RAM 14/07/22 13:41:35 INFO Worker: Spark home: /home/spark/app/spark-1.0.1-bin-2.3.0-cdh5.0.0 14/07/22 13:41:35 INFO WorkerWebUI: Started WorkerWebUI at http://hadoop000:8081 14/07/22 13:41:35 INFO Worker: Connecting to master spark://hadoop000:7077... 14/07/22 13:41:36 INFO Worker: Successfully registered with master spark://hadoop000:7077
三、Application提交过程
A、提交Application
运行spark-shell: $SPARK_HOME/bin/spark-shell --master spark://hadoop000:7077
日志信息:$SPARK_HOME/work
spark-shell属于application,在启动SparkContext的createTaskScheduler创建SparkDeploySchedulerBackend的过程中创建
client = new AppClient(sc.env.actorSystem, masters, appDesc, this, conf) client.start()
会向Master发送RegisterApplication请求
AppClient.scala ==>preStart ==>registerWithMaster ==>tryRegisterAllMasters ==>actor ! RegisterApplication(appDescription)
B、 Master处理RegisterApplication的请求
在Master侧其处理的分支是RegisterApplication;Master在收到RegisterApplication请求之后,Master进行调度:如果有worker已经注册上来,发送LaunchExecutor指令给相应worker
Master.scala ==>case RegisterApplication(description) => { logInfo("Registering app " + description.name) val app = createApplication(description, sender) registerApplication(app) logInfo("Registered app " + description.name + " with ID " + app.id) persistenceEngine.addApplication(app) sender ! RegisteredApplication(app.id, masterUrl) schedule() } ==>schedule ==>launchExecutor(worker, exec) ==> worker.addExecutor(exec) worker.actor ! LaunchExecutor(masterUrl,exec.application.id, exec.id, exec.application.desc, exec.cores, exec.memory) exec.application.driver ! ExecutorAdded(exec.id, worker.id, worker.hostPort, exec.cores, exec.memory)
C、启动Executor
Worker在收到LaunchExecutor指令之后,会启动Executor进程
Worker.scala ==>case LaunchExecutor(masterUrl, appId, execId, appDesc, cores_, memory_) => logInfo("Asked to launch executor %s/%d for %s".format(appId, execId, appDesc.name)) val manager = new ExecutorRunner(appId, execId, appDesc, cores_, memory_, self, workerId, host, appDesc.sparkHome.map(userSparkHome => new File(userSparkHome)).getOrElse(sparkHome), workDir, akkaUrl, ExecutorState.RUNNING) executors(appId + "/" + execId) = manager manager.start() coresUsed += cores_ memoryUsed += memory_ masterLock.synchronized {master ! ExecutorStateChanged(appId, execId, manager.state, None, None)} }
D、注册Executor
启动的Executor进程会根据启动时的入参,将自己注册到Driver中的SchedulerBackend
SparkDeploySchedulerBackend.scala ==>preStart (CoarseGrainedSchedulerBackend) ==> case RegisterExecutor(executorId, hostPort, cores) => logInfo("Registered executor: " + sender + " with ID " + executorId) sender ! RegisteredExecutor(sparkProperties) executorActor(executorId) = sender executorHost(executorId) = Utils.parseHostPort(hostPort)._1 totalCores(executorId) = cores freeCores(executorId) = cores executorAddress(executorId) = sender.path.address addressToExecutorId(sender.path.address) = executorId totalCoreCount.addAndGet(cores) makeOffers() CoarseGrainedExecutorBackend.scala case RegisteredExecutor(sparkProperties) => ogInfo("Successfully registered with driver") executor = new Executor(executorId, Utils.parseHostPort(hostPort)._1, sparkProperties,false)
executor日志信息位置:控制台/$SPARK_HOME/logs
E、运行Task
示例代码:
sc.textFile("hdfs://hadoop000:8020/hello.txt").flatMap(_.split(‘\t‘)).map((_,1)).reduceByKey(_+_).collect
SchedulerBackend收到Executor的注册消息之后,会将提交到的Spark Job分解为多个具体的Task,然后通过LaunchTask指令将这些Task分散到各个Executor上真正的运行。
CoarseGrainedSchedulerBackend.scala def makeOffers() { launchTasks(scheduler.resourceOffers( executorHost.toArray.map {case (id, host) => new WorkerOffer(id, host, freeCores(id))})) } ==>executorActor(task.executorId) ! LaunchTask(new SerializableBuffer(serializedTask)) ==>CoarseGrainedSchedulerBackend case LaunchTask(data) => if (executor == null) { logError("Received LaunchTask command but executor was null") System.exit(1) } else { val ser = SparkEnv.get.closureSerializer.newInstance() val taskDesc = ser.deserialize[TaskDescription](data.value) logInfo("Got assigned task " + taskDesc.taskId) executor.launchTask(this, taskDesc.taskId, taskDesc.serializedTask) }
Master部分日志信息:
14/07/22 15:25:27 INFO master.Master: Registering app Spark shell 14/07/22 15:25:27 INFO master.Master: Registered app Spark shell with ID app-20140722152527-0001 14/07/22 15:25:27 INFO master.Master: Launching executor app-20140722152527-0001/0 on worker worker-20140722134135-hadoop000-48343
Worker部分日志信息:
Spark assembly has been built with Hive, including Datanucleus jars on classpath 14/07/22 15:25:27 INFO Worker: Asked to launch executor app-20140722152527-0001/0 for Spark shell Spark assembly has been built with Hive, including Datanucleus jars on classpath 14/07/22 15:25:28 INFO ExecutorRunner: Launch command: "java" "-cp" "::/home/spark/app/spark-1.0.1-bin-2.3.0-cdh5.0.0/conf:/home/spark/app/spark-1.0.1-bin-2.3.0-cdh5.0.0/lib/spark-assembly-1.0.1-hadoop2.3.0-cdh5.0.0.jar:/home/spark/app/spark-1.0.1-bin-2.3.0-cdh5.0.0/lib/datanucleus-rdbms-3.2.1.jar:/home/spark/app/spark-1.0.1-bin-2.3.0-cdh5.0.0/lib/datanucleus-core-3.2.2.jar:/home/spark/app/spark-1.0.1-bin-2.3.0-cdh5.0.0/lib/datanucleus-api-jdo-3.2.1.jar" "-XX:MaxPermSize=128m" "-Xms1024M" "-Xmx1024M" "org.apache.spark.executor.CoarseGrainedExecutorBackend" "akka.tcp://[email protected]:50515/user/CoarseGrainedScheduler" "0" "hadoop000" "1" "akka.tcp://[email protected]:48343/user/Worker" "app-20140722152527-0001"
控制台部分日志信息:
14/07/22 15:25:31 INFO cluster.SparkDeploySchedulerBackend: Registered executor: Actor[akka.tcp://[email protected]:45150/user/Executor#-791712793] with ID 0 14/07/22 15:25:31 INFO CoarseGrainedExecutorBackend: Successfully registered with driver
每当有新的application注册到master,master都要调度schedule函数将application发送到相应的worker,在对应的worker启动相应的ExecutorBackend,最终的Task就运行在ExecutorBackend中。
Spark分析之Standalone运行过程分析