@Override
  public boolean clearNamedQueue() {
    if (!isBalancerDecisionRecording) {
      return false;
    }
    LOG.debug("Received request to clean up balancer decision queue.");
    balancerDecisionQueue.clear();
    return true;
  }
In-memory Queue service provider for Balancer Decision events
hbase-server/src/main/java/org/apache/hadoop/hbase/namequeues/impl/BalancerDecisionQueueService.java