概要
本次主要分析任务调度的全流程
整体架构流程
调度器,即服务端会定时查询5秒内的任务,然后请求客户端的netty服务器执行对应的JobHandler,其实质就是一个方法调用。执行器执行完之后,将结果反馈给调度器。如果有回调需要处理的,会调用调度器的回调方法进行处理。其中,任务查询这块,会用到自定义的时间轮。具体逻辑,之前在《XXL-JOB之服务端启动流程分析》中讲解过。下面主要分析一下,从任务调度到完成,这整个过程,具体做了哪些事。
技术细节
调度器对任务进行调度,是通过JobTriggerPoolHelper#trigger这个方法处理的:
默认使用快线程池进行执行。如果该任务在执行过程中,执行时间超过了500ms,就记录一下,达到10次之后,后面再执行这个任务,就使用慢线程池执行。这样做的好处是,将执行快的任务和执行慢的任务进行隔离,避免慢任务占用线程资源,拖慢执行快的任务。
进一步调用XxlJobTrigger#trigger:
获取任务的信息,任务的地址,重试次数,分片信息等。进到processTrigger方法:
private static void processTrigger(XxlJobGroup group, XxlJobInfo jobInfo, int finalFailRetryCount, TriggerTypeEnum triggerType, int index, int total){
// param
ExecutorBlockStrategyEnum blockStrategy = ExecutorBlockStrategyEnum.match(jobInfo.getExecutorBlockStrategy(), ExecutorBlockStrategyEnum.SERIAL_EXECUTION); // block strategy
ExecutorRouteStrategyEnum executorRouteStrategyEnum = ExecutorRouteStrategyEnum.match(jobInfo.getExecutorRouteStrategy(), null); // route strategy
String shardingParam = (ExecutorRouteStrategyEnum.SHARDING_BROADCAST==executorRouteStrategyEnum)?String.valueOf(index).concat("/").concat(String.valueOf(total)):null;
// 1、save log-id
XxlJobLog jobLog = new XxlJobLog();
jobLog.setJobGroup(jobInfo.getJobGroup());
jobLog.setJobId(jobInfo.getId());
jobLog.setTriggerTime(new Date());
XxlJobAdminConfig.getAdminConfig().getXxlJobLogDao().save(jobLog);
logger.debug(">>>>>>>>>>> xxl-job trigger start, jobId:{}", jobLog.getId());
// 2、init trigger-param
TriggerParam triggerParam = new TriggerParam();
triggerParam.setJobId(jobInfo.getId());
triggerParam.setExecutorHandler(jobInfo.getExecutorHandler());
triggerParam.setExecutorParams(jobInfo.getExecutorParam());
triggerParam.setExecutorBlockStrategy(jobInfo.getExecutorBlockStrategy());
triggerParam.setExecutorTimeout(jobInfo.getExecutorTimeout());
triggerParam.setLogId(jobLog.getId());
triggerParam.setLogDateTime(jobLog.getTriggerTime().getTime());
triggerParam.setGlueType(jobInfo.getGlueType());
triggerParam.setGlueSource(jobInfo.getGlueSource());
triggerParam.setGlueUpdatetime(jobInfo.getGlueUpdatetime().getTime());
triggerParam.setBroadcastIndex(index);
triggerParam.setBroadcastTotal(total);
// 3、init address
String address = null;
ReturnT<String> routeAddressResult = null;
if (group.getRegistryList()!=null && !group.getRegistryList().isEmpty()) {
if (ExecutorRouteStrategyEnum.SHARDING_BROADCAST == executorRouteStrategyEnum) {
if (index < group.getRegistryList().size()) {
address = group.getRegistryList().get(index);
} else {
address = group.getRegistryList().get(0);
}
} else {
routeAddressResult = executorRouteStrategyEnum.getRouter().route(triggerParam, group.getRegistryList());
if (routeAddressResult.getCode() == ReturnT.SUCCESS_CODE) {
address = routeAddressResult.getContent();
}
}
} else {
routeAddressResult = new ReturnT<String>(ReturnT.FAIL_CODE, I18nUtil.getString("jobconf_trigger_address_empty"));
}
// 4、trigger remote executor
ReturnT<String> triggerResult = null;
if (address != null) {
triggerResult = runExecutor(triggerParam, address);
} else {
triggerResult = new ReturnT<String>(ReturnT.FAIL_CODE, null);
}
// 5、collection trigger info
StringBuffer triggerMsgSb = new StringBuffer();
triggerMsgSb.append(I18nUtil.getString("jobconf_trigger_type")).append(":").append(triggerType.getTitle());
triggerMsgSb.append("<br>").append(I18nUtil.getString("jobconf_trigger_admin_adress")).append(":").append(IpUtil.getIp());
triggerMsgSb.append("<br>").append(I18nUtil.getString("jobconf_trigger_exe_regtype")).append(":")
.append( (group.getAddressType() == 0)?I18nUtil.getString("jobgroup_field_addressType_0"):I18nUtil.getString("jobgroup_field_addressType_1") );
triggerMsgSb.append("<br>").append(I18nUtil.getString("jobconf_trigger_exe_regaddress")).append(":").append(group.getRegistryList());
triggerMsgSb.append("<br>").append(I18nUtil.getString("jobinfo_field_executorRouteStrategy")).append(":").append(executorRouteStrategyEnum.getTitle());
if (shardingParam != null) {
triggerMsgSb.append("("+shardingParam+")");
}
triggerMsgSb.append("<br>").append(I18nUtil.getString("jobinfo_field_executorBlockStrategy")).append(":").append(blockStrategy.getTitle());
triggerMsgSb.append("<br>").append(I18nUtil.getString("jobinfo_field_timeout")).append(":").append(jobInfo.getExecutorTimeout());
triggerMsgSb.append("<br>").append(I18nUtil.getString("jobinfo_field_executorFailRetryCount")).append(":").append(finalFailRetryCount);
triggerMsgSb.append("<br><br><span style=\"color:#00c0ef;\" > >>>>>>>>>>>"+ I18nUtil.getString("jobconf_trigger_run") +"<<<<<<<<<<< </span><br>")
.append((routeAddressResult!=null&&routeAddressResult.getMsg()!=null)?routeAddressResult.getMsg()+"<br><br>":"").append(triggerResult.getMsg()!=null?triggerResult.getMsg():"");
// 6、save log trigger-info
jobLog.setExecutorAddress(address);
jobLog.setExecutorHandler(jobInfo.getExecutorHandler());
jobLog.setExecutorParam(jobInfo.getExecutorParam());
jobLog.setExecutorShardingParam(shardingParam);
jobLog.setExecutorFailRetryCount(finalFailRetryCount);
//jobLog.setTriggerTime();
jobLog.setTriggerCode(triggerResult.getCode());
jobLog.setTriggerMsg(triggerMsgSb.toString());
XxlJobAdminConfig.getAdminConfig().getXxlJobLogDao().updateTriggerInfo(jobLog);
logger.debug(">>>>>>>>>>> xxl-job trigger end, jobId:{}", jobLog.getId());
}
再次封装了执行参数,获取执行器地址,并记录日志。主要逻辑在 runExecutor:
这里主要逻辑是将,执行器的地址 和token封装成一个ExecutorBiz,并且进行了缓存。那么ExecutorBiz是做什么的呢?它其实就是一个用来调用客户端netty服务器的工具类:
下面是客户端netty构建的api,我们对比着看看:
从而我们知道,调度器触发任务执行,最终调用的是/run这个api,在ExecutorBizImpl#run中
public ReturnT<String> run(TriggerParam triggerParam) {
// load old:jobHandler + jobThread
JobThread jobThread = XxlJobExecutor.loadJobThread(triggerParam.getJobId());
IJobHandler jobHandler = jobThread!=null?jobThread.getHandler():null;
String removeOldReason = null;
// valid:jobHandler + jobThread
GlueTypeEnum glueTypeEnum = GlueTypeEnum.match(triggerParam.getGlueType());
if (GlueTypeEnum.BEAN == glueTypeEnum) {
// new jobhandler
IJobHandler newJobHandler = XxlJobExecutor.loadJobHandler(triggerParam.getExecutorHandler());
// valid old jobThread
if (jobThread!=null && jobHandler != newJobHandler) {
// change handler, need kill old thread
removeOldReason = "change jobhandler or glue type, and terminate the old job thread.";
jobThread = null;
jobHandler = null;
}
// valid handler
if (jobHandler == null) {
jobHandler = newJobHandler;
if (jobHandler == null) {
return new ReturnT<String>(ReturnT.FAIL_CODE, "job handler [" + triggerParam.getExecutorHandler() + "] not found.");
}
}
} else if (GlueTypeEnum.GLUE_GROOVY == glueTypeEnum) {
// valid old jobThread
if (jobThread != null &&
!(jobThread.getHandler() instanceof GlueJobHandler
&& ((GlueJobHandler) jobThread.getHandler()).getGlueUpdatetime()==triggerParam.getGlueUpdatetime() )) {
// change handler or gluesource updated, need kill old thread
removeOldReason = "change job source or glue type, and terminate the old job thread.";
jobThread = null;
jobHandler = null;
}
// valid handler
if (jobHandler == null) {
try {
IJobHandler originJobHandler = GlueFactory.getInstance().loadNewInstance(triggerParam.getGlueSource());
jobHandler = new GlueJobHandler(originJobHandler, triggerParam.getGlueUpdatetime());
} catch (Exception e) {
logger.error(e.getMessage(), e);
return new ReturnT<String>(ReturnT.FAIL_CODE, e.getMessage());
}
}
} else if (glueTypeEnum!=null && glueTypeEnum.isScript()) {
// valid old jobThread
if (jobThread != null &&
!(jobThread.getHandler() instanceof ScriptJobHandler
&& ((ScriptJobHandler) jobThread.getHandler()).getGlueUpdatetime()==triggerParam.getGlueUpdatetime() )) {
// change script or gluesource updated, need kill old thread
removeOldReason = "change job source or glue type, and terminate the old job thread.";
jobThread = null;
jobHandler = null;
}
// valid handler
if (jobHandler == null) {
jobHandler = new ScriptJobHandler(triggerParam.getJobId(), triggerParam.getGlueUpdatetime(), triggerParam.getGlueSource(), GlueTypeEnum.match(triggerParam.getGlueType()));
}
} else {
return new ReturnT<String>(ReturnT.FAIL_CODE, "glueType[" + triggerParam.getGlueType() + "] is not valid.");
}
// executor block strategy
if (jobThread != null) {
ExecutorBlockStrategyEnum blockStrategy = ExecutorBlockStrategyEnum.match(triggerParam.getExecutorBlockStrategy(), null);
if (ExecutorBlockStrategyEnum.DISCARD_LATER == blockStrategy) {
// discard when running
if (jobThread.isRunningOrHasQueue()) {
return new ReturnT<String>(ReturnT.FAIL_CODE, "block strategy effect:"+ExecutorBlockStrategyEnum.DISCARD_LATER.getTitle());
}
} else if (ExecutorBlockStrategyEnum.COVER_EARLY == blockStrategy) {
// kill running jobThread
if (jobThread.isRunningOrHasQueue()) {
removeOldReason = "block strategy effect:" + ExecutorBlockStrategyEnum.COVER_EARLY.getTitle();
jobThread = null;
}
} else {
// just queue trigger
}
}
// replace thread (new or exists invalid)
if (jobThread == null) {
jobThread = XxlJobExecutor.registJobThread(triggerParam.getJobId(), jobHandler, removeOldReason);
}
// push data to queue
ReturnT<String> pushResult = jobThread.pushTriggerQueue(triggerParam);
return pushResult;
}
1、第一次执行的时候,会将任务id、任务对应执行的执行器和一个线程进行绑定,并且以任务id作为key进行了缓存;
2、下次再执行的时候,直接从缓存中通过任务id,获取一个线程进行任务的处理。从而可以看出,有多少个任务,就会产生多少个线程。这里为啥不使用线程池处理?我的理解:①线程池的初始化指标不太好指定,线程数少了,容易产生任务堆积,从而发生阻塞。多了又浪费资源;②线程池没法做到隔离。每个任务的执行时间是不一样的,执行慢的任务,会长久占用线程资源,影响其他任务的执行。
3、作者的做法是,一个任务分配一个线程,一个线程配置个队列。并且也会将线程和任务id进行绑定之后,缓存起来,方便根据任务id查找对应处理的线程。这其实也运用了线程池化的思想。任务的执行相互隔离,也便于进行个性化处理。上面代码中还有一个细节:IJobHandler newJobHandler = XxlJobExecutor.loadJobHandler(triggerParam.getExecutorHandler());每次都会重新查一下,这是为什么?我们分析过,客户端在启动时,会找到所有的执行器,并以执行器的名字作为key,缓存在map中,这里的loadJobHandler就是根据名字从缓存中找到对应的执行器。那什么情况下,线程中绑定的执行器和初始化时缓存的执行器会不一样呢?只有一种场景,就是在可视化界面改了执行器的名字,相当于改了任务绑定的执行器的名字。那么又会出现2种情况:如果新名字可以在初始化缓存中找到对应的执行器,就将原来绑定的线程终止掉,然后生成一个新的线程,重新绑定任务id和执行器,后面的任务就都用新的执行器执行了;如果找不到,就直接返回执行错误,并记录日志。找不到执行器这种情况,应该是客户端没有进行重启导致的。
4、任务的执行,就是向任务对应线程配置的队列里面丢任务,线程再从自己的队列里面获取任务执行,典型的生产者-消费者模型:
public void run() {
// init
try {
handler.init();
} catch (Throwable e) {
logger.error(e.getMessage(), e);
}
// execute
while(!toStop){
running = false;
idleTimes++;
TriggerParam triggerParam = null;
try {
// to check toStop signal, we need cycle, so wo cannot use queue.take(), instand of poll(timeout)
triggerParam = triggerQueue.poll(3L, TimeUnit.SECONDS);
if (triggerParam!=null) {
running = true;
idleTimes = 0;
triggerLogIdSet.remove(triggerParam.getLogId());
// log filename, like "logPath/yyyy-MM-dd/9999.log"
String logFileName = XxlJobFileAppender.makeLogFileName(new Date(triggerParam.getLogDateTime()), triggerParam.getLogId());
//这里将任务对应的参数放到了上下文中,所以,如果需要使用参数,可以直接从上下文中获取
XxlJobContext xxlJobContext = new XxlJobContext(
triggerParam.getJobId(),
triggerParam.getExecutorParams(),
logFileName,
triggerParam.getBroadcastIndex(),
triggerParam.getBroadcastTotal());
// init job context
XxlJobContext.setXxlJobContext(xxlJobContext);
// execute
XxlJobHelper.log("<br>----------- xxl-job job execute start -----------<br>----------- Param:" + xxlJobContext.getJobParam());
if (triggerParam.getExecutorTimeout() > 0) {
// limit timeout
Thread futureThread = null;
try {
FutureTask<Boolean> futureTask = new FutureTask<Boolean>(new Callable<Boolean>() {
@Override
public Boolean call() throws Exception {
// init job context
XxlJobContext.setXxlJobContext(xxlJobContext);
handler.execute();
return true;
}
});
futureThread = new Thread(futureTask);
futureThread.start();
Boolean tempResult = futureTask.get(triggerParam.getExecutorTimeout(), TimeUnit.SECONDS);
} catch (TimeoutException e) {
XxlJobHelper.log("<br>----------- xxl-job job execute timeout");
XxlJobHelper.log(e);
// handle result
XxlJobHelper.handleTimeout("job execute timeout ");
} finally {
futureThread.interrupt();
}
} else {
// just execute
handler.execute();
}
// valid execute handle data
if (XxlJobContext.getXxlJobContext().getHandleCode() <= 0) {
XxlJobHelper.handleFail("job handle result lost.");
} else {
String tempHandleMsg = XxlJobContext.getXxlJobContext().getHandleMsg();
tempHandleMsg = (tempHandleMsg!=null&&tempHandleMsg.length()>50000)
?tempHandleMsg.substring(0, 50000).concat("...")
:tempHandleMsg;
XxlJobContext.getXxlJobContext().setHandleMsg(tempHandleMsg);
}
XxlJobHelper.log("<br>----------- xxl-job job execute end(finish) -----------<br>----------- Result: handleCode="
+ XxlJobContext.getXxlJobContext().getHandleCode()
+ ", handleMsg = "
+ XxlJobContext.getXxlJobContext().getHandleMsg()
);
} else {
if (idleTimes > 30) {
if(triggerQueue.size() == 0) { // avoid concurrent trigger causes jobId-lost
XxlJobExecutor.removeJobThread(jobId, "excutor idel times over limit.");
}
}
}
} catch (Throwable e) {
if (toStop) {
XxlJobHelper.log("<br>----------- JobThread toStop, stopReason:" + stopReason);
}
// handle result
StringWriter stringWriter = new StringWriter();
e.printStackTrace(new PrintWriter(stringWriter));
String errorMsg = stringWriter.toString();
XxlJobHelper.handleFail(errorMsg);
XxlJobHelper.log("<br>----------- JobThread Exception:" + errorMsg + "<br>----------- xxl-job job execute end(error) -----------");
} finally {
if(triggerParam != null) {
// callback handler info
if (!toStop) {
// commonm
TriggerCallbackThread.pushCallBack(new HandleCallbackParam(
triggerParam.getLogId(),
triggerParam.getLogDateTime(),
XxlJobContext.getXxlJobContext().getHandleCode(),
XxlJobContext.getXxlJobContext().getHandleMsg() )
);
} else {
// is killed
TriggerCallbackThread.pushCallBack(new HandleCallbackParam(
triggerParam.getLogId(),
triggerParam.getLogDateTime(),
XxlJobContext.HANDLE_CODE_FAIL,
stopReason + " [job running, killed]" )
);
}
}
}
}
// callback trigger request in queue
while(triggerQueue !=null && triggerQueue.size()>0){
TriggerParam triggerParam = triggerQueue.poll();
if (triggerParam!=null) {
// is killed
TriggerCallbackThread.pushCallBack(new HandleCallbackParam(
triggerParam.getLogId(),
triggerParam.getLogDateTime(),
XxlJobContext.HANDLE_CODE_FAIL,
stopReason + " [job not executed, in the job queue, killed.]")
);
}
}
// destroy
try {
handler.destroy();
} catch (Throwable e) {
logger.error(e.getMessage(), e);
}
logger.info(">>>>>>>>>>> xxl-job JobThread stoped, hashCode:{}", Thread.currentThread());
}
依次执行执行器的init方法、execute方法和destroy方法。然后将执行结果通过回调的方式告诉调度器。
小结
1、在执行execute方法时,如果需要使用任务绑定的参数,可以直接从XxlJobContext这个上下文中获取;
2、大量使用了生产者-消费者模型进行了解耦,提高了吞吐量。