001/**
002 * Licensed to the Apache Software Foundation (ASF) under one
003 * or more contributor license agreements.  See the NOTICE file
004 * distributed with this work for additional information
005 * regarding copyright ownership.  The ASF licenses this file
006 * to you under the Apache License, Version 2.0 (the
007 * "License"); you may not use this file except in compliance
008 * with the License.  You may obtain a copy of the License at
009 *
010 *     http://www.apache.org/licenses/LICENSE-2.0
011 *
012 * Unless required by applicable law or agreed to in writing, software
013 * distributed under the License is distributed on an "AS IS" BASIS,
014 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
015 * See the License for the specific language governing permissions and
016 * limitations under the License.
017 */
018package org.apache.hadoop.ha;
019
020import java.io.IOException;
021
022import org.apache.hadoop.classification.InterfaceAudience;
023import org.apache.hadoop.classification.InterfaceStability;
024import org.apache.hadoop.ha.HAServiceProtocol.StateChangeRequestInfo;
025import org.apache.hadoop.ipc.RemoteException;
026
027/**
028 * Helper for making {@link HAServiceProtocol} RPC calls. This helper
029 * unwraps the {@link RemoteException} to specific exceptions.
030 */
031@InterfaceAudience.Public
032@InterfaceStability.Evolving
033public class HAServiceProtocolHelper {
034  public static void monitorHealth(HAServiceProtocol svc,
035      StateChangeRequestInfo reqInfo)
036      throws IOException {
037    try {
038      svc.monitorHealth();
039    } catch (RemoteException e) {
040      throw e.unwrapRemoteException(HealthCheckFailedException.class);
041    }
042  }
043
044  public static void transitionToActive(HAServiceProtocol svc,
045      StateChangeRequestInfo reqInfo)
046      throws IOException {
047    try {
048      svc.transitionToActive(reqInfo);
049    } catch (RemoteException e) {
050      throw e.unwrapRemoteException(ServiceFailedException.class);
051    }
052  }
053
054  public static void transitionToStandby(HAServiceProtocol svc,
055      StateChangeRequestInfo reqInfo)
056      throws IOException {
057    try {
058      svc.transitionToStandby(reqInfo);
059    } catch (RemoteException e) {
060      throw e.unwrapRemoteException(ServiceFailedException.class);
061    }
062  }
063}