功能：
定期去扫描元数据表CoordinatorJobBean，将满足条件的Job实体化；
// default is 300sec (5min)
int schedulingInterval = Services.get().getConf().getInt(CONF_SCHEDULING_INTERVAL, lookupInterval);
Runnable lookupTriggerJobsRunnable = new CoordMaterializeTriggerRunnable(materializationWindow, lookupInterval);
services.get(SchedulerService.class).schedule(lookupTriggerJobsRunnable, 10, schedulingInterval,SchedulerService.Unit.SEC);
CoordMaterializeTriggerRunnable:
oozie里面的触发机制：
1、启动一个定时执行器，每隔 schedulingInterval 时间运行一次 CoordMaterializeTriggerRunnable；
2、查询CoordinatorJobBean根据时间和条数限制获取本次需要实例化的CoordinatorJobBean；
技巧： 在CoordinatorJobBean中有个字段 nextMaterializedTimestamp 表明，在这个时间点之前的实例已经存在，为了尽可能的让任务的实例尽可能在触发之前
实例就产生，而不是事后产生，在查询CoordinatorJobBean使用的时候不是使用当前时间，而是使用未来的一个时间： new Date().getTime() + lookupInterval * 1000
3、异步去实例化 CoordinatorJobBean 下的 action；
4、在实例化action的时候，生成的是窗口期内的一批实例，在类 CoordMaterializeTransitionXCommand中实现；
5、loadState()：加载 CoordinatorJobBean 信息，计算这次要实例化的时间窗口： startMatdTime 和 endMatdTime；
6、materialize()：根据不同的计算方式(cron、自定义)来在这个时间窗口内循环的产生action的实例；
7、更新 CoordinatorJobBean 状态，记录 endMatdTime、lastActionNumber（时间累加）、状态置为running状态、如果jobEndTime< endMatdTime
说明这个 CoordinatorJobBean 实例化工作已经结束，标记 job.setDoneMaterialization();
8、performWrites():更新数据库
9、notifyParent():通知上层结构 bundle;
/** * This runnable class will run in every "interval" to queue CoordMaterializeTransitionXCommand.
*/
static class CoordMaterializeTriggerRunnable implements Runnable {
private int materializationWindow;
private int lookupInterval;
private long delay = 0;
private List<XCallable<Void>> callables;
private List<XCallable<Void>> delayedCallables;
private XLog LOG = XLog.getLog(getClass());
public CoordMaterializeTriggerRunnable(int materializationWindow, int lookupInterval) {
this.materializationWindow = materializationWindow;
this.lookupInterval = lookupInterval;
}
@Override
public void run() {
LockToken lock = null;
// first check if there is some other running instance from the same service;
try {
lock = Services.get().get(MemoryLocksService.class)
.getWriteLock(CoordMaterializeTriggerService.class.getName(), lockTimeout);
if (lock != null) {
runCoordJobMatLookup();
if (null != callables) {
boolean ret = Services.get().get(CallableQueueService.class).queueSerial(callables);
if (ret == false) {
XLog.getLog(getClass()).warn(
"Unable to queue the callables commands for CoordMaterializeTriggerRunnable. "
+ "Most possibly command queue is full. Queue size is :"
+ Services.get().get(CallableQueueService.class).queueSize());
}
callables = null;
}
if (null != delayedCallables) {
boolean ret = Services.get().get(CallableQueueService.class)
.queueSerial(delayedCallables, this.delay);
if (ret == false) {
XLog.getLog(getClass()).warn(
"Unable to queue the delayedCallables commands for CoordMaterializeTriggerRunnable. "
+ "Most possibly Callable queue is full. Queue size is :"
+ Services.get().get(CallableQueueService.class).queueSize());
}
delayedCallables = null;
this.delay = 0;
}
}
else {
LOG.debug("Can't obtain lock, skipping");
}
}
catch (Exception e) {
LOG.error("Exception", e);
}
finally {
if (lock != null) {
lock.release();
LOG.info("Released lock for [{0}]", CoordMaterializeTriggerService.class.getName());
}
}
}
/**
* Recover coordinator jobs that should be materialized
* @throws JPAExecutorException
*/
private void runCoordJobMatLookup() throws JPAExecutorException {
List<UpdateEntry> updateList = new ArrayList<UpdateEntry>(); XLog.Info.get().clear();
XLog LOG = XLog.getLog(getClass());
try {
// get current date
Date currDate = new Date(new Date().getTime() + lookupInterval * 1000);
// get list of all jobs that have actions that should be materialized.
int materializationLimit = ConfigurationService.getInt(CONF_MATERIALIZATION_SYSTEM_LIMIT);
materializeCoordJobs(currDate, materializationLimit, LOG, updateList);
}
catch (Exception ex) {
LOG.error("Exception while attempting to materialize coordinator jobs, {0}", ex.getMessage(), ex);
}
finally {
BatchQueryExecutor.getInstance().executeBatchInsertUpdateDelete(null, updateList, null);
}
}
private void materializeCoordJobs(Date currDate, int limit, XLog LOG, List<UpdateEntry> updateList)
throws JPAExecutorException {
try {
List<CoordinatorJobBean> materializeJobs = CoordJobQueryExecutor.getInstance().getList(
CoordJobQuery.GET_COORD_JOBS_OLDER_FOR_MATERIALIZATION, currDate, limit);
LOG.info("CoordMaterializeTriggerService - Curr Date= " + DateUtils.formatDateOozieTZ(currDate)
+ ", Num jobs to materialize = " + materializeJobs.size());
for (CoordinatorJobBean coordJob : materializeJobs) {
Services.get().get(InstrumentationService.class).get()
.incr(INSTRUMENTATION_GROUP, INSTR_MAT_JOBS_COUNTER, 1);
queueCallable(new CoordMaterializeTransitionXCommand(coordJob.getId(), materializationWindow));
coordJob.setLastModifiedTime(new Date());
updateList.add(new UpdateEntry<CoordJobQuery>(CoordJobQuery.UPDATE_COORD_JOB_LAST_MODIFIED_TIME,
coordJob));
}
}
catch (JPAExecutorException jex) {
LOG.warn("JPAExecutorException while attempting to materialize coordinator jobs", jex);
}
}
/**
* Adds callables to a list. If the number of callables in the list reaches {@link
* CoordMaterializeTriggerService#CONF_CALLABLE_BATCH_SIZE}, the entire batch is queued and the callables list
* is reset.
*
* @param callable the callable to queue.
*/
private void queueCallable(XCallable<Void> callable) {
if (callables == null) {
callables = new ArrayList<XCallable<Void>>();
}
callables.add(callable);
if (callables.size() == ConfigurationService.getInt(CONF_CALLABLE_BATCH_SIZE)) { boolean ret = Services.get().get(CallableQueueService.class).queueSerial(callables);
if (ret == false) {
XLog.getLog(getClass()).warn(
"Unable to queue the callables commands for CoordMaterializeTriggerRunnable. "
+ "Most possibly command queue is full. Queue size is :"
+ Services.get().get(CallableQueueService.class).queueSize());
}
callables = new ArrayList<XCallable<Void>>();
}
}
}
