js 做网站seo小白入门教学

系列文章目录

一、DataX详解和架构介绍
二、DataX源码分析 JobContainer
三、DataX源码分析 TaskGroupContainer
四、DataX源码分析 TaskExecutor
五、DataX源码分析 reader
六、DataX源码分析 writer
七、DataX源码分析 Channel

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TaskGroupContainer

DataX的TaskGroupContainer是JobContainer将所有task分配到TaskGroup中执行的一个容器。这个容器的主要入口是start方法，该方法会执行两个主要任务：
初始化task执行相关的状态信息和 循环检测所有任务的执行状态 。此外，TaskGroupContainer还有一个名为reportTaskGroupCommunication的方法，用于向容器汇报状态。这个方法会收集当前TaskGroupContainer对应所有Task的通信信息，并将其合并成一个通信信息。

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初始化

设置配置文件Configuration
初始化监控
设置jobId
设置taskGroupId
设置channel类实例channelClazz

start方法详细步骤

1、初始化task执行相关的状态信息

• taskConfigMap：taskId与其对应的Congifuration的map映射集合
• 待运行的任务队列taskQueue
• 运行失败任务taskFailedExecutorMap
• 正在执行的任务集合runTasks
• 任务开始时间taskStartTimeMap。

2、开始执行任务while (true)循环

1.判断task状态
循环遍历所有任务，如果任务尚未完成跳过。如果任务已经完成从任务列表中删除。如果任务失败判断是否支持重试，如支持重试并重试次数没有超过最大限制则重试执行。
2.发现该taskGroup下taskExecutor的总状态失败则汇报错误
3.有任务未执行，且正在运行的任务数小于最大通道限制，创建TaskExecutor实例，调用doStart真正执行数据同步任务，从待运行task列表中删除同时加入到正在运行的队列。TaskExecutor构建的时候，生成一个reader、channel和writer，并启动两个线程，reader生产数据写入channel，writer从channel中读数据，任务执行完毕时，通过wirter将任务状态置为成功。
4.检查执行队列和所有的任务状态，如果所有的任务都执行成功，则汇报taskGroup的状态并从循环中退出。
5.如果当前时间已经超出汇报时间的interval，那么我们需要马上汇报
6.当所有的执行完成从while中退出之后，再次全局汇报当前的任务状态

TaskGroupContainer源码

/**
* task任务运行容器
**/
public class TaskGroupContainer extends AbstractContainer {private static final Logger LOG = LoggerFactory.getLogger(TaskGroupContainer.class);/*** 当前taskGroup所属jobId*/private long jobId;/*** 当前taskGroupId*/private int taskGroupId;/*** 使用的channel类*/private String channelClazz;/*** task收集器使用的类*/private String taskCollectorClass;private TaskMonitor taskMonitor = TaskMonitor.getInstance();public TaskGroupContainer(Configuration configuration) {super(configuration);initCommunicator(configuration);this.jobId = this.configuration.getLong(CoreConstant.DATAX_CORE_CONTAINER_JOB_ID);this.taskGroupId = this.configuration.getInt(CoreConstant.DATAX_CORE_CONTAINER_TASKGROUP_ID);this.channelClazz = this.configuration.getString(CoreConstant.DATAX_CORE_TRANSPORT_CHANNEL_CLASS);this.taskCollectorClass = this.configuration.getString(CoreConstant.DATAX_CORE_STATISTICS_COLLECTOR_PLUGIN_TASKCLASS);}private void initCommunicator(Configuration configuration) {super.setContainerCommunicator(new StandaloneTGContainerCommunicator(configuration));}public long getJobId() {return jobId;}public int getTaskGroupId() {return taskGroupId;}@Overridepublic void start() {try {/*** 状态check时间间隔，较短，可以把任务及时分发到对应channel中*/int sleepIntervalInMillSec = this.configuration.getInt(CoreConstant.DATAX_CORE_CONTAINER_TASKGROUP_SLEEPINTERVAL, 100);/*** 状态汇报时间间隔，稍长，避免大量汇报*/long reportIntervalInMillSec = this.configuration.getLong(CoreConstant.DATAX_CORE_CONTAINER_TASKGROUP_REPORTINTERVAL,10000);/*** 2分钟汇报一次性能统计*/// 获取channel数目int channelNumber = this.configuration.getInt(CoreConstant.DATAX_CORE_CONTAINER_TASKGROUP_CHANNEL);int taskMaxRetryTimes = this.configuration.getInt(CoreConstant.DATAX_CORE_CONTAINER_TASK_FAILOVER_MAXRETRYTIMES, 1);long taskRetryIntervalInMsec = this.configuration.getLong(CoreConstant.DATAX_CORE_CONTAINER_TASK_FAILOVER_RETRYINTERVALINMSEC, 10000);long taskMaxWaitInMsec = this.configuration.getLong(CoreConstant.DATAX_CORE_CONTAINER_TASK_FAILOVER_MAXWAITINMSEC, 60000);List<Configuration> taskConfigs = this.configuration.getListConfiguration(CoreConstant.DATAX_JOB_CONTENT);if(LOG.isDebugEnabled()) {LOG.debug("taskGroup[{}]'s task configs[{}]", this.taskGroupId,JSON.toJSONString(taskConfigs));}int taskCountInThisTaskGroup = taskConfigs.size();LOG.info(String.format("taskGroupId=[%d] start [%d] channels for [%d] tasks.",this.taskGroupId, channelNumber, taskCountInThisTaskGroup));this.containerCommunicator.registerCommunication(taskConfigs);Map<Integer, Configuration> taskConfigMap = buildTaskConfigMap(taskConfigs); //taskId与task配置List<Configuration> taskQueue = buildRemainTasks(taskConfigs); //待运行task列表Map<Integer, TaskExecutor> taskFailedExecutorMap = new HashMap<Integer, TaskExecutor>(); //taskId与上次失败实例List<TaskExecutor> runTasks = new ArrayList<TaskExecutor>(channelNumber); //正在运行taskMap<Integer, Long> taskStartTimeMap = new HashMap<Integer, Long>(); //任务开始时间long lastReportTimeStamp = 0;Communication lastTaskGroupContainerCommunication = new Communication();while (true) {//1.判断task状态boolean failedOrKilled = false;Map<Integer, Communication> communicationMap = containerCommunicator.getCommunicationMap();for(Map.Entry<Integer, Communication> entry : communicationMap.entrySet()){Integer taskId = entry.getKey();Communication taskCommunication = entry.getValue();if(!taskCommunication.isFinished()){continue;}TaskExecutor taskExecutor = removeTask(runTasks, taskId);//上面从runTasks里移除了，因此对应在monitor里移除taskMonitor.removeTask(taskId);//失败，看task是否支持failover，重试次数未超过最大限制if(taskCommunication.getState() == State.FAILED){taskFailedExecutorMap.put(taskId, taskExecutor);if(taskExecutor.supportFailOver() && taskExecutor.getAttemptCount() < taskMaxRetryTimes){taskExecutor.shutdown(); //关闭老的executorcontainerCommunicator.resetCommunication(taskId); //将task的状态重置Configuration taskConfig = taskConfigMap.get(taskId);taskQueue.add(taskConfig); //重新加入任务列表}else{failedOrKilled = true;break;}}else if(taskCommunication.getState() == State.KILLED){failedOrKilled = true;break;}else if(taskCommunication.getState() == State.SUCCEEDED){Long taskStartTime = taskStartTimeMap.get(taskId);if(taskStartTime != null){Long usedTime = System.currentTimeMillis() - taskStartTime;LOG.info("taskGroup[{}] taskId[{}] is successed, used[{}]ms",this.taskGroupId, taskId, usedTime);//usedTime*1000*1000 转换成PerfRecord记录的ns，这里主要是简单登记，进行最长任务的打印。因此增加特定静态方法PerfRecord.addPerfRecord(taskGroupId, taskId, PerfRecord.PHASE.TASK_TOTAL,taskStartTime, usedTime * 1000L * 1000L);taskStartTimeMap.remove(taskId);taskConfigMap.remove(taskId);}}}// 2.发现该taskGroup下taskExecutor的总状态失败则汇报错误if (failedOrKilled) {lastTaskGroupContainerCommunication = reportTaskGroupCommunication(lastTaskGroupContainerCommunication, taskCountInThisTaskGroup);throw DataXException.asDataXException(FrameworkErrorCode.PLUGIN_RUNTIME_ERROR, lastTaskGroupContainerCommunication.getThrowable());}//3.有任务未执行，且正在运行的任务数小于最大通道限制Iterator<Configuration> iterator = taskQueue.iterator();while(iterator.hasNext() && runTasks.size() < channelNumber){Configuration taskConfig = iterator.next();Integer taskId = taskConfig.getInt(CoreConstant.TASK_ID);int attemptCount = 1;TaskExecutor lastExecutor = taskFailedExecutorMap.get(taskId);if(lastExecutor!=null){attemptCount = lastExecutor.getAttemptCount() + 1;long now = System.currentTimeMillis();long failedTime = lastExecutor.getTimeStamp();if(now - failedTime < taskRetryIntervalInMsec){  //未到等待时间，继续留在队列continue;}if(!lastExecutor.isShutdown()){ //上次失败的task仍未结束if(now - failedTime > taskMaxWaitInMsec){markCommunicationFailed(taskId);reportTaskGroupCommunication(lastTaskGroupContainerCommunication, taskCountInThisTaskGroup);throw DataXException.asDataXException(CommonErrorCode.WAIT_TIME_EXCEED, "task failover等待超时");}else{lastExecutor.shutdown(); //再次尝试关闭continue;}}else{LOG.info("taskGroup[{}] taskId[{}] attemptCount[{}] has already shutdown",this.taskGroupId, taskId, lastExecutor.getAttemptCount());}}Configuration taskConfigForRun = taskMaxRetryTimes > 1 ? taskConfig.clone() : taskConfig;TaskExecutor taskExecutor = new TaskExecutor(taskConfigForRun, attemptCount);taskStartTimeMap.put(taskId, System.currentTimeMillis());taskExecutor.doStart();iterator.remove();runTasks.add(taskExecutor);//上面，增加task到runTasks列表，因此在monitor里注册。taskMonitor.registerTask(taskId, this.containerCommunicator.getCommunication(taskId));taskFailedExecutorMap.remove(taskId);LOG.info("taskGroup[{}] taskId[{}] attemptCount[{}] is started",this.taskGroupId, taskId, attemptCount);}//4.任务列表为空，executor已结束, 搜集状态为success--->成功if (taskQueue.isEmpty() && isAllTaskDone(runTasks) && containerCommunicator.collectState() == State.SUCCEEDED) {// 成功的情况下，也需要汇报一次。否则在任务结束非常快的情况下，采集的信息将会不准确lastTaskGroupContainerCommunication = reportTaskGroupCommunication(lastTaskGroupContainerCommunication, taskCountInThisTaskGroup);LOG.info("taskGroup[{}] completed it's tasks.", this.taskGroupId);break;}// 5.如果当前时间已经超出汇报时间的interval，那么我们需要马上汇报long now = System.currentTimeMillis();if (now - lastReportTimeStamp > reportIntervalInMillSec) {lastTaskGroupContainerCommunication = reportTaskGroupCommunication(lastTaskGroupContainerCommunication, taskCountInThisTaskGroup);lastReportTimeStamp = now;//taskMonitor对于正在运行的task，每reportIntervalInMillSec进行检查for(TaskExecutor taskExecutor:runTasks){taskMonitor.report(taskExecutor.getTaskId(),this.containerCommunicator.getCommunication(taskExecutor.getTaskId()));}}Thread.sleep(sleepIntervalInMillSec);}//6.最后还要汇报一次reportTaskGroupCommunication(lastTaskGroupContainerCommunication, taskCountInThisTaskGroup);} catch (Throwable e) {Communication nowTaskGroupContainerCommunication = this.containerCommunicator.collect();if (nowTaskGroupContainerCommunication.getThrowable() == null) {nowTaskGroupContainerCommunication.setThrowable(e);}nowTaskGroupContainerCommunication.setState(State.FAILED);this.containerCommunicator.report(nowTaskGroupContainerCommunication);throw DataXException.asDataXException(FrameworkErrorCode.RUNTIME_ERROR, e);}finally {if(!PerfTrace.getInstance().isJob()){//最后打印cpu的平均消耗，GC的统计VMInfo vmInfo = VMInfo.getVmInfo();if (vmInfo != null) {vmInfo.getDelta(false);LOG.info(vmInfo.totalString());}LOG.info(PerfTrace.getInstance().summarizeNoException());}}}private Map<Integer, Configuration> buildTaskConfigMap(List<Configuration> configurations){Map<Integer, Configuration> map = new HashMap<Integer, Configuration>();for(Configuration taskConfig : configurations){int taskId = taskConfig.getInt(CoreConstant.TASK_ID);map.put(taskId, taskConfig);}return map;}private List<Configuration> buildRemainTasks(List<Configuration> configurations){List<Configuration> remainTasks = new LinkedList<Configuration>();for(Configuration taskConfig : configurations){remainTasks.add(taskConfig);}return remainTasks;}private TaskExecutor removeTask(List<TaskExecutor> taskList, int taskId){Iterator<TaskExecutor> iterator = taskList.iterator();while(iterator.hasNext()){TaskExecutor taskExecutor = iterator.next();if(taskExecutor.getTaskId() == taskId){iterator.remove();return taskExecutor;}}return null;}private boolean isAllTaskDone(List<TaskExecutor> taskList){for(TaskExecutor taskExecutor : taskList){if(!taskExecutor.isTaskFinished()){return false;}}return true;}private Communication reportTaskGroupCommunication(Communication lastTaskGroupContainerCommunication, int taskCount){Communication nowTaskGroupContainerCommunication = this.containerCommunicator.collect();nowTaskGroupContainerCommunication.setTimestamp(System.currentTimeMillis());Communication reportCommunication = CommunicationTool.getReportCommunication(nowTaskGroupContainerCommunication,lastTaskGroupContainerCommunication, taskCount);this.containerCommunicator.report(reportCommunication);return reportCommunication;}private void markCommunicationFailed(Integer taskId){Communication communication = containerCommunicator.getCommunication(taskId);communication.setState(State.FAILED);}/*** TaskExecutor是一个完整task的执行器* 其中包括1：1的reader和writer*/class TaskExecutor {private Configuration taskConfig;private int taskId;private int attemptCount;private Channel channel;private Thread readerThread;private Thread writerThread;private ReaderRunner readerRunner;private WriterRunner writerRunner;/*** 该处的taskCommunication在多处用到：* 1. channel* 2. readerRunner和writerRunner* 3. reader和writer的taskPluginCollector*/private Communication taskCommunication;public TaskExecutor(Configuration taskConf, int attemptCount) {// 获取该taskExecutor的配置this.taskConfig = taskConf;Validate.isTrue(null != this.taskConfig.getConfiguration(CoreConstant.JOB_READER)&& null != this.taskConfig.getConfiguration(CoreConstant.JOB_WRITER),"[reader|writer]的插件参数不能为空!");// 得到taskIdthis.taskId = this.taskConfig.getInt(CoreConstant.TASK_ID);this.attemptCount = attemptCount;/*** 由taskId得到该taskExecutor的Communication* 要传给readerRunner和writerRunner，同时要传给channel作统计用*/this.taskCommunication = containerCommunicator.getCommunication(taskId);Validate.notNull(this.taskCommunication,String.format("taskId[%d]的Communication没有注册过", taskId));this.channel = ClassUtil.instantiate(channelClazz,Channel.class, configuration);this.channel.setCommunication(this.taskCommunication);/*** 获取transformer的参数*/List<TransformerExecution> transformerInfoExecs = TransformerUtil.buildTransformerInfo(taskConfig);/*** 生成writerThread*/writerRunner = (WriterRunner) generateRunner(PluginType.WRITER);this.writerThread = new Thread(writerRunner,String.format("%d-%d-%d-writer",jobId, taskGroupId, this.taskId));//通过设置thread的contextClassLoader，即可实现同步和主程序不通的加载器this.writerThread.setContextClassLoader(LoadUtil.getJarLoader(PluginType.WRITER, this.taskConfig.getString(CoreConstant.JOB_WRITER_NAME)));/*** 生成readerThread*/readerRunner = (ReaderRunner) generateRunner(PluginType.READER,transformerInfoExecs);this.readerThread = new Thread(readerRunner,String.format("%d-%d-%d-reader",jobId, taskGroupId, this.taskId));/*** 通过设置thread的contextClassLoader，即可实现同步和主程序不通的加载器*/this.readerThread.setContextClassLoader(LoadUtil.getJarLoader(PluginType.READER, this.taskConfig.getString(CoreConstant.JOB_READER_NAME)));}public void doStart() {this.writerThread.start();// reader没有起来，writer不可能结束if (!this.writerThread.isAlive() || this.taskCommunication.getState() == State.FAILED) {throw DataXException.asDataXException(FrameworkErrorCode.RUNTIME_ERROR,this.taskCommunication.getThrowable());}this.readerThread.start();// 这里reader可能很快结束if (!this.readerThread.isAlive() && this.taskCommunication.getState() == State.FAILED) {// 这里有可能出现Reader线上启动即挂情况 对于这类情况 需要立刻抛出异常throw DataXException.asDataXException(FrameworkErrorCode.RUNTIME_ERROR,this.taskCommunication.getThrowable());}}private AbstractRunner generateRunner(PluginType pluginType) {return generateRunner(pluginType, null);}private AbstractRunner generateRunner(PluginType pluginType, List<TransformerExecution> transformerInfoExecs) {AbstractRunner newRunner = null;TaskPluginCollector pluginCollector;switch (pluginType) {case READER:newRunner = LoadUtil.loadPluginRunner(pluginType,this.taskConfig.getString(CoreConstant.JOB_READER_NAME));newRunner.setJobConf(this.taskConfig.getConfiguration(CoreConstant.JOB_READER_PARAMETER));pluginCollector = ClassUtil.instantiate(taskCollectorClass, AbstractTaskPluginCollector.class,configuration, this.taskCommunication,PluginType.READER);RecordSender recordSender;if (transformerInfoExecs != null && transformerInfoExecs.size() > 0) {recordSender = new BufferedRecordTransformerExchanger(taskGroupId, this.taskId, this.channel,this.taskCommunication ,pluginCollector, transformerInfoExecs);} else {recordSender = new BufferedRecordExchanger(this.channel, pluginCollector);}((ReaderRunner) newRunner).setRecordSender(recordSender);/*** 设置taskPlugin的collector，用来处理脏数据和job/task通信*/newRunner.setTaskPluginCollector(pluginCollector);break;case WRITER:newRunner = LoadUtil.loadPluginRunner(pluginType,this.taskConfig.getString(CoreConstant.JOB_WRITER_NAME));newRunner.setJobConf(this.taskConfig.getConfiguration(CoreConstant.JOB_WRITER_PARAMETER));pluginCollector = ClassUtil.instantiate(taskCollectorClass, AbstractTaskPluginCollector.class,configuration, this.taskCommunication,PluginType.WRITER);((WriterRunner) newRunner).setRecordReceiver(new BufferedRecordExchanger(this.channel, pluginCollector));/*** 设置taskPlugin的collector，用来处理脏数据和job/task通信*/newRunner.setTaskPluginCollector(pluginCollector);break;default:throw DataXException.asDataXException(FrameworkErrorCode.ARGUMENT_ERROR, "Cant generateRunner for:" + pluginType);}newRunner.setTaskGroupId(taskGroupId);newRunner.setTaskId(this.taskId);newRunner.setRunnerCommunication(this.taskCommunication);return newRunner;}// 检查任务是否结束private boolean isTaskFinished() {// 如果reader 或 writer没有完成工作，那么直接返回工作没有完成if (readerThread.isAlive() || writerThread.isAlive()) {return false;}if(taskCommunication==null || !taskCommunication.isFinished()){return false;}return true;}private int getTaskId(){return taskId;}private long getTimeStamp(){return taskCommunication.getTimestamp();}private int getAttemptCount(){return attemptCount;}private boolean supportFailOver(){return writerRunner.supportFailOver();}private void shutdown(){writerRunner.shutdown();readerRunner.shutdown();if(writerThread.isAlive()){writerThread.interrupt();}if(readerThread.isAlive()){readerThread.interrupt();}}private boolean isShutdown(){return !readerThread.isAlive() && !writerThread.isAlive();}}
}