@Override
  public void alterWMTrigger(WMTrigger trigger)
      throws NoSuchObjectException, InvalidOperationException, MetaException {
    boolean commited = false;
    Query query = null;
    try {
      openTransaction();
      MWMResourcePlan resourcePlan = getMWMResourcePlan(
          trigger.getResourcePlanName(), trigger.getNs(), true);
      MWMTrigger mTrigger = getTrigger(resourcePlan, trigger.getTriggerName());
      // Update the object.
      if (trigger.isSetTriggerExpression()) {
        mTrigger.setTriggerExpression(trigger.getTriggerExpression());
      }
      if (trigger.isSetActionExpression()) {
        mTrigger.setActionExpression(trigger.getActionExpression());
      }
      if (trigger.isSetIsInUnmanaged()) {
        mTrigger.setIsInUnmanaged(trigger.isIsInUnmanaged());
      }
      commited = commitTransaction();
    } finally {
      rollbackAndCleanup(commited, query);
    }
  }
This is a cleanup method which is used to rollback a active transaction
if the success flag is false and close the associated Query object. This method is used
internally and visible for testing purposes only
@param success Rollback the current active transaction if false
@param query Query object which needs to be closed
standalone-metastore/metastore-server/src/main/java/org/apache/hadoop/hive/metastore/ObjectStore.java