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Spark Master资源调度–SparkContext向所有master注册
更多资源
- github: https://github.com/opensourceteams/spark-scala-maven
- csdn(汇总视频在线看): https://blog.csdn.net/thinktothings/article/details/84726769
Youtube视频分享
- Spark Master资源调度–SparkContext向所有master注册 : https://youtu.be/AXxCnCc5Mh0
Bilibili视频分享
- Spark Master资源调度–SparkContext向所有master注册 : https://www.bilibili.com/video/av37442295/
SparkContext启动向master发送消息
- ClientEndpoint向master发送消息: RegisterApplication
/*** Register with all masters asynchronously and returns an array `Future`s for cancellation.*/private def tryRegisterAllMasters(): Array[JFuture[_]] = {for (masterAddress <- masterRpcAddresses) yield {registerMasterThreadPool.submit(new Runnable {override def run(): Unit = try {if (registered.get) {return}logInfo("Connecting to master " + masterAddress.toSparkURL + "...")val masterRef =rpcEnv.setupEndpointRef(Master.SYSTEM_NAME, masterAddress, Master.ENDPOINT_NAME)masterRef.send(RegisterApplication(appDescription, self))} catch {case ie: InterruptedException => // Cancelledcase NonFatal(e) => logWarning(s"Failed to connect to master $masterAddress", e)}})}}
master处理消息RegisterApplication
- 创建 Application 并注册到master上
- Application 保存到 master 存储引擎中
- 向driver发送已注册成功消息: RegisteredApplication
case RegisterApplication(description, driver) => {// TODO Prevent repeated registrations from some driverif (state == RecoveryState.STANDBY) {// ignore, don't send response} else {logInfo("Registering app " + description.name)val app = createApplication(description, driver)registerApplication(app)logInfo("Registered app " + description.name + " with ID " + app.id)persistenceEngine.addApplication(app)driver.send(RegisteredApplication(app.id, self))schedule()}}- 过滤所有已注册的Worker(状态为ALIVE)
- 遍历 waitingDrivers，如果有等待中的Drivers,给worker发送启动Driver消息: LaunchDriver
- 调用在worker上启动executor方法
/*** Schedule the currently available resources among waiting apps. This method will be called* every time a new app joins or resource availability changes.*/private def schedule(): Unit = {if (state != RecoveryState.ALIVE) {return}// Drivers take strict precedence over executorsval shuffledAliveWorkers = Random.shuffle(workers.toSeq.filter(_.state == WorkerState.ALIVE))val numWorkersAlive = shuffledAliveWorkers.sizevar curPos = 0for (driver <- waitingDrivers.toList) { // iterate over a copy of waitingDrivers// We assign workers to each waiting driver in a round-robin fashion. For each driver, we// start from the last worker that was assigned a driver, and continue onwards until we have// explored all alive workers.var launched = falsevar numWorkersVisited = 0while (numWorkersVisited < numWorkersAlive && !launched) {val worker = shuffledAliveWorkers(curPos)numWorkersVisited += 1if (worker.memoryFree >= driver.desc.mem && worker.coresFree >= driver.desc.cores) {launchDriver(worker, driver)waitingDrivers -= driverlaunched = true}curPos = (curPos + 1) % numWorkersAlive}}startExecutorsOnWorkers()}
- 过滤waitingApps,刚才注册的Application已经在ArrayBuffer中
- 对已注册的worker进行过滤
- 过滤条件状态为ALIVE,可用cpu内核数大于等于每个executor的内核数，可用内存大于等于Application在每个executor需要的内存数
- 对可用worker进行排序(按可用内核数从大到小排序)
- 调用方法 scheduleExecutorsOnWorkers，worker给executor分配多少个cpu内核
/*** Schedule and launch executors on workers*/private def startExecutorsOnWorkers(): Unit = {// Right now this is a very simple FIFO scheduler. We keep trying to fit in the first app// in the queue, then the second app, etc.for (app <- waitingApps if app.coresLeft > 0) {val coresPerExecutor: Option[Int] = app.desc.coresPerExecutor// Filter out workers that don't have enough resources to launch an executorval usableWorkers = workers.toArray.filter(_.state == WorkerState.ALIVE).filter(worker => worker.memoryFree >= app.desc.memoryPerExecutorMB &&worker.coresFree >= coresPerExecutor.getOrElse(1)).sortBy(_.coresFree).reverseval assignedCores = scheduleExecutorsOnWorkers(app, usableWorkers, spreadOutApps)// Now that we've decided how many cores to allocate on each worker, let's allocate themfor (pos <- 0 until usableWorkers.length if assignedCores(pos) > 0) {allocateWorkerResourceToExecutors(app, assignedCores(pos), coresPerExecutor, usableWorkers(pos))}}}
- 进行具体的当前Application在Worker上给executor分配几个cpu内核
/*** Schedule executors to be launched on the workers.* Returns an array containing number of cores assigned to each worker.** There are two modes of launching executors. The first attempts to spread out an application's* executors on as many workers as possible, while the second does the opposite (i.e. launch them* on as few workers as possible). The former is usually better for data locality purposes and is* the default.** The number of cores assigned to each executor is configurable. When this is explicitly set,* multiple executors from the same application may be launched on the same worker if the worker* has enough cores and memory. Otherwise, each executor grabs all the cores available on the* worker by default, in which case only one executor may be launched on each worker.** It is important to allocate coresPerExecutor on each worker at a time (instead of 1 core* at a time). Consider the following example: cluster has 4 workers with 16 cores each.* User requests 3 executors (spark.cores.max = 48, spark.executor.cores = 16). If 1 core is* allocated at a time, 12 cores from each worker would be assigned to each executor.* Since 12 < 16, no executors would launch [SPARK-8881].*/private def scheduleExecutorsOnWorkers(app: ApplicationInfo,usableWorkers: Array[WorkerInfo],spreadOutApps: Boolean): Array[Int] = {val coresPerExecutor = app.desc.coresPerExecutorval minCoresPerExecutor = coresPerExecutor.getOrElse(1)val oneExecutorPerWorker = coresPerExecutor.isEmptyval memoryPerExecutor = app.desc.memoryPerExecutorMBval numUsable = usableWorkers.lengthval assignedCores = new Array[Int](numUsable) // Number of cores to give to each workerval assignedExecutors = new Array[Int](numUsable) // Number of new executors on each workervar coresToAssign = math.min(app.coresLeft, usableWorkers.map(_.coresFree).sum)/** Return whether the specified worker can launch an executor for this app. */def canLaunchExecutor(pos: Int): Boolean = {val keepScheduling = coresToAssign >= minCoresPerExecutorval enoughCores = usableWorkers(pos).coresFree - assignedCores(pos) >= minCoresPerExecutor// If we allow multiple executors per worker, then we can always launch new executors.// Otherwise, if there is already an executor on this worker, just give it more cores.val launchingNewExecutor = !oneExecutorPerWorker || assignedExecutors(pos) == 0if (launchingNewExecutor) {val assignedMemory = assignedExecutors(pos) * memoryPerExecutorval enoughMemory = usableWorkers(pos).memoryFree - assignedMemory >= memoryPerExecutorval underLimit = assignedExecutors.sum + app.executors.size < app.executorLimitkeepScheduling && enoughCores && enoughMemory && underLimit} else {// We're adding cores to an existing executor, so no need// to check memory and executor limitskeepScheduling && enoughCores}}// Keep launching executors until no more workers can accommodate any// more executors, or if we have reached this application's limitsvar freeWorkers = (0 until numUsable).filter(canLaunchExecutor)while (freeWorkers.nonEmpty) {freeWorkers.foreach { pos =>var keepScheduling = truewhile (keepScheduling && canLaunchExecutor(pos)) {coresToAssign -= minCoresPerExecutorassignedCores(pos) += minCoresPerExecutor// If we are launching one executor per worker, then every iteration assigns 1 core// to the executor. Otherwise, every iteration assigns cores to a new executor.if (oneExecutorPerWorker) {assignedExecutors(pos) = 1} else {assignedExecutors(pos) += 1}// Spreading out an application means spreading out its executors across as// many workers as possible. If we are not spreading out, then we should keep// scheduling executors on this worker until we use all of its resources.// Otherwise, just move on to the next worker.if (spreadOutApps) {keepScheduling = false}}}freeWorkers = freeWorkers.filter(canLaunchExecutor)}assignedCores}
- 分配worker资源给executor
- 给worker发送启动executor消息： LaunchExecutor
- 给driver发送Executor已增加消息：ExecutorAdded
/*** Allocate a worker's resources to one or more executors.* @param app the info of the application which the executors belong to* @param assignedCores number of cores on this worker for this application* @param coresPerExecutor number of cores per executor* @param worker the worker info*/private def allocateWorkerResourceToExecutors(app: ApplicationInfo,assignedCores: Int,coresPerExecutor: Option[Int],worker: WorkerInfo): Unit = {// If the number of cores per executor is specified, we divide the cores assigned// to this worker evenly among the executors with no remainder.// Otherwise, we launch a single executor that grabs all the assignedCores on this worker.val numExecutors = coresPerExecutor.map { assignedCores / _ }.getOrElse(1)val coresToAssign = coresPerExecutor.getOrElse(assignedCores)for (i <- 1 to numExecutors) {val exec = app.addExecutor(worker, coresToAssign)launchExecutor(worker, exec)app.state = ApplicationState.RUNNING}}
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