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     */
018    package org.apache.hadoop.ha;
019    
020    import java.io.IOException;
021    
022    import org.apache.hadoop.classification.InterfaceAudience;
023    import org.apache.hadoop.classification.InterfaceStability;
024    import org.apache.hadoop.ipc.RemoteException;
025    
026    /**
027     * Helper for making {@link HAServiceProtocol} RPC calls. This helper
028     * unwraps the {@link RemoteException} to specific exceptions.
029     */
030    @InterfaceAudience.Public
031    @InterfaceStability.Evolving
032    public class HAServiceProtocolHelper {
033      public static void monitorHealth(HAServiceProtocol svc)
034          throws IOException {
035        try {
036          svc.monitorHealth();
037        } catch (RemoteException e) {
038          throw e.unwrapRemoteException(HealthCheckFailedException.class);
039        }
040      }
041    
042      public static void transitionToActive(HAServiceProtocol svc)
043          throws IOException {
044        try {
045          svc.transitionToActive();
046        } catch (RemoteException e) {
047          throw e.unwrapRemoteException(ServiceFailedException.class);
048        }
049      }
050    
051      public static void transitionToStandby(HAServiceProtocol svc)
052          throws IOException {
053        try {
054          svc.transitionToStandby();
055        } catch (RemoteException e) {
056          throw e.unwrapRemoteException(ServiceFailedException.class);
057        }
058      }
059    }