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1   /**
2    * Licensed to the Apache Software Foundation (ASF) under one
3    * or more contributor license agreements.  See the NOTICE file
4    * distributed with this work for additional information
5    * regarding copyright ownership.  The ASF licenses this file
6    * to you under the Apache License, Version 2.0 (the
7    * "License"); you may not use this file except in compliance
8    * with the License.  You may obtain a copy of the License at
9    *
10   *     http://www.apache.org/licenses/LICENSE-2.0
11   *
12   * Unless required by applicable law or agreed to in writing, software
13   * distributed under the License is distributed on an "AS IS" BASIS,
14   * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
15   * See the License for the specific language governing permissions and
16   * limitations under the License.
17   */
18  
19  package org.apache.hadoop.hbase;
20  
21  import java.io.IOException;
22  
23  import org.apache.hadoop.conf.Configurable;
24  import org.apache.hadoop.hbase.classification.InterfaceAudience;
25  
26  
27  /**
28   * ClusterManager is an api to manage servers in a distributed environment. It provides services
29   * for starting / stopping / killing Hadoop/HBase daemons. Concrete implementations provide actual
30   * functionality for carrying out deployment-specific tasks.
31   */
32  @InterfaceAudience.Private
33  interface ClusterManager extends Configurable {
34    /**
35     * Type of the service daemon
36     */
37    public static enum ServiceType {
38      HADOOP_NAMENODE("namenode"),
39      HADOOP_DATANODE("datanode"),
40      HADOOP_JOBTRACKER("jobtracker"),
41      HADOOP_TASKTRACKER("tasktracker"),
42      HBASE_MASTER("master"),
43      HBASE_REGIONSERVER("regionserver");
44  
45      private String name;
46  
47      ServiceType(String name) {
48        this.name = name;
49      }
50  
51      public String getName() {
52        return name;
53      }
54  
55      @Override
56      public String toString() {
57        return getName();
58      }
59    }
60  
61    /**
62     * Start the service on the given host
63     */
64    void start(ServiceType service, String hostname, int port) throws IOException;
65  
66    /**
67     * Stop the service on the given host
68     */
69    void stop(ServiceType service, String hostname, int port) throws IOException;
70  
71    /**
72     * Restart the service on the given host
73     */
74    void restart(ServiceType service, String hostname, int port) throws IOException;
75  
76    /**
77     * Kills the service running on the given host
78     */
79    void kill(ServiceType service, String hostname, int port) throws IOException;
80  
81    /**
82     * Suspends the service running on the given host
83     */
84    void suspend(ServiceType service, String hostname, int port) throws IOException;
85  
86    /**
87     * Resumes the services running on the given host
88     */
89    void resume(ServiceType service, String hostname, int port) throws IOException;
90  
91    /**
92     * Returns whether the service is running on the remote host. This only checks whether the
93     * service still has a pid.
94     */
95    String isRunning(ServiceType service, String hostname, int port) throws IOException;
96  
97    /* TODO: further API ideas:
98     *
99     * //return services running on host:
100    * ServiceType[] getRunningServicesOnHost(String hostname);
101    *
102    * //return which services can be run on host (for example, to query whether hmaster can run on this host)
103    * ServiceType[] getRunnableServicesOnHost(String hostname);
104    *
105    * //return which hosts can run this service
106    * String[] getRunnableHostsForService(ServiceType service);
107    */
108 
109 }