java - Quartz 失败时重试

Question

假设我有一个这样配置的触发器:

<bean id="updateInsBBTrigger"         
    class="org.springframework.scheduling.quartz.CronTriggerBean">
    <property name="jobDetail" ref="updateInsBBJobDetail"/>
    <!--  run every morning at 5 AM  -->
    <property name="cronExpression" value="0 0 5 * * ?"/>
</bean>

触发器必须与另一个应用程序连接，如果出现任何问题(如连接失败)，它应该每 10 分钟重试该任务最多五次或直到成功。有什么方法可以将触发器配置为这样工作？

Answer 1

我会推荐一个像这样的实现来在失败后恢复工作:

final JobDataMap jobDataMap = jobCtx.getJobDetail().getJobDataMap();
// the keys doesn't exist on first retry
final int retries = jobDataMap.containsKey(COUNT_MAP_KEY) ? jobDataMap.getIntValue(COUNT_MAP_KEY) : 0;

// to stop after awhile
if (retries < MAX_RETRIES) {
  log.warn("Retry job " + jobCtx.getJobDetail());

  // increment the number of retries
  jobDataMap.put(COUNT_MAP_KEY, retries + 1);

  final JobDetail job = jobCtx
      .getJobDetail()
      .getJobBuilder()
       // to track the number of retries
      .withIdentity(jobCtx.getJobDetail().getKey().getName() + " - " + retries, "FailingJobsGroup")
      .usingJobData(jobDataMap)
      .build();

  final OperableTrigger trigger = (OperableTrigger) TriggerBuilder
      .newTrigger()
      .forJob(job)
       // trying to reduce back pressure, you can use another algorithm
      .startAt(new Date(jobCtx.getFireTime().getTime() + (retries*100))) 
      .build();

  try {
    // schedule another job to avoid blocking threads
    jobCtx.getScheduler().scheduleJob(job, trigger);
  } catch (SchedulerException e) {
    log.error("Error creating job");
    throw new JobExecutionException(e);
  }
}

为什么？

1. 它不会阻止 Quartz Workers
2. 它将避免背压。使用 setRefireImmediately，作业将立即被解雇，这可能会导致背压问题