@Override
    public void abort(String why, Throwable e) {
      if (this.aborted) return;

      this.aborted = true;
      LOG.warn("Aborting because: " + why, e);
      this.executor.shutdownNow();
    }
Attempt to cleanly shutdown any running tasks - allows currently running tasks to cleanly
finish
hbase-server/src/test/java/org/apache/hadoop/hbase/procedure/SimpleRSProcedureManager.java