public void rememberCompletedDag(QueryIdentifier queryIdentifier) {
    if (completedDagMap.add(queryIdentifier)) {
      // We will remember completed DAG for an hour to avoid execution out-of-order fragments.
      executorService.schedule(new DagMapCleanerCallable(queryIdentifier), 1, TimeUnit.HOURS);
    } else {
      LOG.warn("Couldn't add {} to completed dag set", queryIdentifier);
    }
  }
Register completion for a query
@param queryIdentifier
@param deleteDelay
llap-server/src/java/org/apache/hadoop/hive/llap/daemon/impl/QueryTracker.java