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本文主要研究一下PowerJob的HeavyTaskTracker的dispatchTask
dispatchTask
tech/powerjob/worker/core/tracker/task/heavy/HeavyTaskTracker.java
代码语言：javascript复制 protected void dispatchTask(TaskDO task, String processorTrackerAddress) {
// 1. 持久化，更新数据库（如果更新数据库失败，可能导致重复执行，先不处理）
TaskDO updateEntity = new TaskDO();
updateEntity.setStatus(TaskStatus.DISPATCH_SUCCESS_WORKER_UNCHECK.getValue());
// 写入处理该任务的 ProcessorTracker
updateEntity.setAddress(processorTrackerAddress);
boolean success = taskPersistenceService.updateTask(instanceId, task.getTaskId(), updateEntity);
if (!success) {
log.warn("[TaskTracker-{}] dispatch task(taskId={},taskName={}) failed due to update task status failed.", instanceId, task.getTaskId(), task.getTaskName());
return;
}
// 2. 更新 ProcessorTrackerStatus 状态
ptStatusHolder.getProcessorTrackerStatus(processorTrackerAddress).setDispatched(true);
// 3. 初始化缓存
taskId2BriefInfo.put(task.getTaskId(), new TaskBriefInfo(task.getTaskId(), TaskStatus.DISPATCH_SUCCESS_WORKER_UNCHECK, -1L));
// 4. 任务派发
TaskTrackerStartTaskReq startTaskReq = new TaskTrackerStartTaskReq(instanceInfo, task, workerRuntime.getWorkerAddress());
TransportUtils.ttStartPtTask(startTaskReq, processorTrackerAddress, workerRuntime.getTransporter());
log.debug("[TaskTracker-{}] dispatch task(taskId={},taskName={}) successfully.", instanceId, task.getTaskId(), task.getTaskName());
}
HeavyTaskTracker的dispatchTask方法通过TransportUtils.ttStartPtTask将任务派发到ProcessorTracker
ttStartPtTask
tech/powerjob/worker/common/utils/TransportUtils.java
代码语言：javascript复制 public static void ttStartPtTask(TaskTrackerStartTaskReq req, String address, Transporter transporter) {
final URL url = easyBuildUrl(ServerType.WORKER, WPT_PATH, WPT_HANDLER_START_TASK, address);
transporter.tell(url, req);
}
ttStartPtTask方法往rootPath为processorTracker，handlerPath为startTask的接口发送TaskTrackerStartTaskReq
TaskTrackerStartTaskReq
tech/powerjob/worker/pojo/request/TaskTrackerStartTaskReq.java
代码语言：javascript复制@Getter
@Setter
@NoArgsConstructor
public class TaskTrackerStartTaskReq implements PowerSerializable {
// TaskTracker 地址
private String taskTrackerAddress;
private InstanceInfo instanceInfo;
private String taskId;
private String taskName;
private byte[] taskContent;
// 子任务当前重试次数
private int taskCurrentRetryNums;
// 秒级任务专用
private long subInstanceId;
private String logConfig;
/**
* 创建 TaskTrackerStartTaskReq，该构造方法必须在 TaskTracker 节点调用
*/
public TaskTrackerStartTaskReq(InstanceInfo instanceInfo, TaskDO task, String taskTrackerAddress) {
this.taskTrackerAddress = taskTrackerAddress;
this.instanceInfo = instanceInfo;
this.taskId = task.getTaskId();
this.taskName = task.getTaskName();
this.taskContent = task.getTaskContent();
this.taskCurrentRetryNums = task.getFailedCnt();
this.subInstanceId = task.getSubInstanceId();
this.logConfig = instanceInfo.getLogConfig();
}
}
TaskTrackerStartTaskReq包含了taskTrackerAddress、instanceInfo、taskId、taskName、taskContent等信息
onReceiveTaskTrackerStartTaskReq
tech/powerjob/worker/actors/ProcessorTrackerActor.java
代码语言：javascript复制@Slf4j
@Actor(path = RemoteConstant.WPT_PATH)
public class ProcessorTrackerActor {
private final WorkerRuntime workerRuntime;
public ProcessorTrackerActor(WorkerRuntime workerRuntime) {
this.workerRuntime = workerRuntime;
}
/**
* 处理来自TaskTracker的task执行请求
* @param req 请求
*/
@Handler(path = RemoteConstant.WPT_HANDLER_START_TASK, processType = ProcessType.NO_BLOCKING)
public void onReceiveTaskTrackerStartTaskReq(TaskTrackerStartTaskReq req) {
Long instanceId = req.getInstanceInfo().getInstanceId();
// 创建 ProcessorTracker 一定能成功
ProcessorTracker processorTracker = ProcessorTrackerManager.getProcessorTracker(
instanceId,
req.getTaskTrackerAddress(),
() -> new ProcessorTracker(req, workerRuntime));
TaskDO task = new TaskDO();
task.setTaskId(req.getTaskId());
task.setTaskName(req.getTaskName());
task.setTaskContent(req.getTaskContent());
task.setFailedCnt(req.getTaskCurrentRetryNums());
task.setSubInstanceId(req.getSubInstanceId());
processorTracker.submitTask(task);
}
//......
}
ProcessorTrackerActor的onReceiveTaskTrackerStartTaskReq方法用于处理TaskTrackerStartTaskReq，它主要是创建ProcessorTracker，然后执行性submit方法
ProcessorTracker
tech/powerjob/worker/core/tracker/processor/ProcessorTracker.java
代码语言：javascript复制 public ProcessorTracker(TaskTrackerStartTaskReq request, WorkerRuntime workerRuntime) {
try {
// 赋值
this.startTime = System.currentTimeMillis();
this.workerRuntime = workerRuntime;
this.instanceInfo = request.getInstanceInfo();
this.instanceId = request.getInstanceInfo().getInstanceId();
this.taskTrackerAddress = request.getTaskTrackerAddress();
this.omsLogger = OmsLoggerFactory.build(instanceId, request.getLogConfig(), workerRuntime);
this.statusReportRetryQueue = Queues.newLinkedBlockingQueue();
this.lastIdleTime = -1L;
this.lastCompletedTaskCount = 0L;
// 初始化 线程池，TimingPool 启动的任务会检查 ThreadPool，所以必须先初始化线程池，否则NPE
initThreadPool();
// 初始化定时任务
initTimingJob();
// 初始化 Processor
processorBean = workerRuntime.getProcessorLoader().load(new ProcessorDefinition().setProcessorType(instanceInfo.getProcessorType()).setProcessorInfo(instanceInfo.getProcessorInfo()));
log.info("[ProcessorTracker-{}] ProcessorTracker was successfully created!", instanceId);
} catch (Throwable t) {
log.warn("[ProcessorTracker-{}] create ProcessorTracker failed, all tasks submitted here will fail.", instanceId, t);
lethal = true;
lethalReason = ExceptionUtils.getMessage(t);
}
}
ProcessorTracker的构造器会initThreadPool、initTimingJob、加载processorBean
initThreadPool
代码语言：javascript复制
private static final int THREAD_POOL_QUEUE_MAX_SIZE = 128;
private void initThreadPool() {
int poolSize = calThreadPoolSize();
// 待执行队列，为了防止对内存造成较大压力，内存队列不能太大
BlockingQueue<Runnable> queue = new ArrayBlockingQueue<>(THREAD_POOL_QUEUE_MAX_SIZE);
// 自定义线程池中线程名称 (PowerJob Processor Pool -> PPP)
ThreadFactory threadFactory = new ThreadFactoryBuilder().setNameFormat("PPP-%d").build();
// 拒绝策略：直接抛出异常
RejectedExecutionHandler rejectionHandler = new ThreadPoolExecutor.AbortPolicy();
threadPool = new ThreadPoolExecutor(poolSize, poolSize, 60L, TimeUnit.SECONDS, queue, threadFactory, rejectionHandler);
// 当没有任务执行时，允许销毁核心线程（即线程池最终存活线程个数可能为0）
threadPool.allowCoreThreadTimeOut(true);
}
private int calThreadPoolSize() {
ExecuteType executeType = ExecuteType.valueOf(instanceInfo.getExecuteType());
ProcessorType processorType = ProcessorType.valueOf(instanceInfo.getProcessorType());
// 脚本类自带线程池，不过为了少一点逻辑判断，还是象征性分配一个线程
if (processorType == ProcessorType.PYTHON || processorType == ProcessorType.SHELL) {
return 1;
}
if (executeType == ExecuteType.MAP_REDUCE || executeType == ExecuteType.MAP) {
return instanceInfo.getThreadConcurrency();
}
if (TimeExpressionType.FREQUENT_TYPES.contains(instanceInfo.getTimeExpressionType())) {
return instanceInfo.getThreadConcurrency();
}
return 2;
}
initThreadPool先根据不同的processorType获取线程池大小，然后创建大小为128的ArrayBlockingQueue，然后设定线程名称前缀
PPP-%d"，设定rejectionHandler为AbortPolicy，最后创建ThreadPoolExecutor，设置allowCoreThreadTimeOut为true
initTimingJob
代码语言：javascript复制 private void initTimingJob() {
// PowerJob Processor TimingPool
ThreadFactory threadFactory = new ThreadFactoryBuilder().setNameFormat("PPT-%d").build();
timingPool = Executors.newSingleThreadScheduledExecutor(threadFactory);
timingPool.scheduleAtFixedRate(new CheckerAndReporter(), 0, 10, TimeUnit.SECONDS);
}
initTimingJob方法设定线程名称前缀为
PPT-%d"，然后通过Executors.newSingleThreadScheduledExecutor创建timingPool，调度CheckerAndReporter
submitTask
代码语言：javascript复制 public void submitTask(TaskDO newTask) {
// 一旦 ProcessorTracker 出现异常，所有提交到此处的任务直接返回失败，防止形成死锁
// 死锁分析：TT创建PT，PT创建失败，无法定期汇报心跳，TT长时间未收到PT心跳，认为PT宕机（确实宕机了），无法选择可用的PT再次派发任务，死锁形成，GG斯密达 T_T
if (lethal) {
ProcessorReportTaskStatusReq report = new ProcessorReportTaskStatusReq()
.setInstanceId(instanceId)
.setSubInstanceId(newTask.getSubInstanceId())
.setTaskId(newTask.getTaskId())
.setStatus(TaskStatus.WORKER_PROCESS_FAILED.getValue())
.setResult(lethalReason)
.setReportTime(System.currentTimeMillis());
TransportUtils.ptReportTask(report, taskTrackerAddress, workerRuntime);
return;
}
boolean success = false;
// 1. 设置值并提交执行
newTask.setInstanceId(instanceInfo.getInstanceId());
newTask.setAddress(taskTrackerAddress);
HeavyProcessorRunnable heavyProcessorRunnable = new HeavyProcessorRunnable(instanceInfo, taskTrackerAddress, newTask, processorBean, omsLogger, statusReportRetryQueue, workerRuntime);
try {
threadPool.submit(heavyProcessorRunnable);
success = true;
} catch (RejectedExecutionException ignore) {
log.warn("[ProcessorTracker-{}] submit task(taskId={},taskName={}) to ThreadPool failed due to ThreadPool has too much task waiting to process, this task will dispatch to other ProcessorTracker.",
instanceId, newTask.getTaskId(), newTask.getTaskName());
} catch (Exception e) {
log.error("[ProcessorTracker-{}] submit task(taskId={},taskName={}) to ThreadPool failed.", instanceId, newTask.getTaskId(), newTask.getTaskName(), e);
}
// 2. 回复接收成功
if (success) {
ProcessorReportTaskStatusReq reportReq = new ProcessorReportTaskStatusReq();
reportReq.setInstanceId(instanceId);
reportReq.setSubInstanceId(newTask.getSubInstanceId());
reportReq.setTaskId(newTask.getTaskId());
reportReq.setStatus(TaskStatus.WORKER_RECEIVED.getValue());
reportReq.setReportTime(System.currentTimeMillis());
TransportUtils.ptReportTask(reportReq, taskTrackerAddress, workerRuntime);
log.debug("[ProcessorTracker-{}] submit task(taskId={}, taskName={}) success, current queue size: {}.",
instanceId, newTask.getTaskId(), newTask.getTaskName(), threadPool.getQueue().size());
}
}
submitTask方法主要是创建HeavyProcessorRunnable，然后通过threadPool提交
HeavyProcessorRunnable
tech/powerjob/worker/core/processor/runnable/HeavyProcessorRunnable.java
代码语言：javascript复制@Slf4j
@AllArgsConstructor
@SuppressWarnings("squid:S1181")
public class HeavyProcessorRunnable implements Runnable {
private final InstanceInfo instanceInfo;
private final String taskTrackerAddress;
private final TaskDO task;
private final ProcessorBean processorBean;
private final OmsLogger omsLogger;
/**
* 重试队列，ProcessorTracker 将会定期重新上报处理结果
*/
private final Queue<ProcessorReportTaskStatusReq> statusReportRetryQueue;
private final WorkerRuntime workerRuntime;
//......
public void run() {
// 切换线程上下文类加载器（否则用的是 Worker 类加载器，不存在容器类，在序列化/反序列化时会报 ClassNotFoundException）
Thread.currentThread().setContextClassLoader(processorBean.getClassLoader());
try {
innerRun();
} catch (InterruptedException ignore) {
// ignore
} catch (Throwable e) {
reportStatus(TaskStatus.WORKER_PROCESS_FAILED, e.toString(), null, null);
log.error("[ProcessorRunnable-{}] execute failed, please contact the author(@KFCFans) to fix the bug!", task.getInstanceId(), e);
} finally {
ThreadLocalStore.clear();
}
}
//......
}
HeavyProcessorRunnable的run方法主要是执行innerRun方法
innerRun
代码语言：javascript复制 public void innerRun() throws InterruptedException {
final BasicProcessor processor = processorBean.getProcessor();
String taskId = task.getTaskId();
Long instanceId = task.getInstanceId();
log.debug("[ProcessorRunnable-{}] start to run task(taskId={}&taskName={})", instanceId, taskId, task.getTaskName());
ThreadLocalStore.setTask(task);
ThreadLocalStore.setRuntimeMeta(workerRuntime);
// 0. 构造任务上下文
WorkflowContext workflowContext = constructWorkflowContext();
TaskContext taskContext = constructTaskContext();
taskContext.setWorkflowContext(workflowContext);
// 1. 上报执行信息
reportStatus(TaskStatus.WORKER_PROCESSING, null, null, null);
ProcessResult processResult;
ExecuteType executeType = ExecuteType.valueOf(instanceInfo.getExecuteType());
// 2. 根任务 & 广播执行 特殊处理
if (TaskConstant.ROOT_TASK_NAME.equals(task.getTaskName()) && executeType == ExecuteType.BROADCAST) {
// 广播执行：先选本机执行 preProcess，完成后 TaskTracker 再为所有 Worker 生成子 Task
handleBroadcastRootTask(instanceId, taskContext);
return;
}
// 3. 最终任务特殊处理（一定和 TaskTracker 处于相同的机器）
if (TaskConstant.LAST_TASK_NAME.equals(task.getTaskName())) {
handleLastTask(taskId, instanceId, taskContext, executeType);
return;
}
// 4. 正式提交运行
try {
processResult = processor.process(taskContext);
if (processResult == null) {
processResult = new ProcessResult(false, "ProcessResult can't be null");
}
} catch (Throwable e) {
log.warn("[ProcessorRunnable-{}] task(id={},name={}) process failed.", instanceId, taskContext.getTaskId(), taskContext.getTaskName(), e);
processResult = new ProcessResult(false, e.toString());
}
reportStatus(processResult.isSuccess() ? TaskStatus.WORKER_PROCESS_SUCCESS : TaskStatus.WORKER_PROCESS_FAILED, suit(processResult.getMsg()), null, workflowContext.getAppendedContextData());
}
innerRun先构建taskContext，然后reportStatus为WORKER_PROCESSING，之后针对广播的root任务执行handleBroadcastRootTask，最后通过processor.process(taskContext)执行任务，这里catch了Throwable，出现异常则返回ProcessResult(false, e.toString())，最后根据处理结果reportStatus为WORKER_PROCESS_SUCCESS或者WORKER_PROCESS_FAILED
小结
HeavyTaskTracker的dispatchTask方法通过TransportUtils.ttStartPtTask将任务派发到ProcessorTracker；ProcessorTrackerActor的onReceiveTaskTrackerStartTaskReq方法用于处理TaskTrackerStartTaskReq，它主要是创建ProcessorTracker，然后执行性submit方法；ProcessorTracker的构造器会initThreadPool、initTimingJob、加载processorBean；submitTask方法主要是创建HeavyProcessorRunnable，然后通过threadPool提交；HeavyProcessorRunnable的run方法主要是执行innerRun方法，innerRun主要是执行processor.process(taskContext)，这里catch了Throwable，出现异常则返回ProcessResult(false, e.toString())。
