@Override
  public void killJobs(String tag, long timestamp) {
    try {
      LOG.info("Looking for jobs to kill...");
      Set<ApplicationId> childJobs = getYarnChildJobs(tag, timestamp);
      if (childJobs.isEmpty()) {
        LOG.info("No jobs found from");
        return;
      } else {
        LOG.info(String.format("Found MR jobs count: %d", childJobs.size()));
        LOG.info("Killing all found jobs");

        YarnClient yarnClient = YarnClient.createYarnClient();
        yarnClient.init(conf);
        yarnClient.start();
        for (ApplicationId app: childJobs) {
          LOG.info(String.format("Killing job: %s ...", app));
          yarnClient.killApplication(app);
          LOG.info(String.format("Job %s killed", app));
        }
      }
    } catch (YarnException ye) {
      throw new RuntimeException("Exception occurred while killing child job(s)", ye);
    } catch (IOException ioe) {
      throw new RuntimeException("Exception occurred while killing child job(s)", ioe);
    }
  }
Kills all jobs tagged with the given tag that have been started after the
given timestamp.
shims/0.23/src/main/java/org/apache/hadoop/mapred/WebHCatJTShim23.java