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1   /**
2    *
3    * Licensed to the Apache Software Foundation (ASF) under one
4    * or more contributor license agreements.  See the NOTICE file
5    * distributed with this work for additional information
6    * regarding copyright ownership.  The ASF licenses this file
7    * to you under the Apache License, Version 2.0 (the
8    * "License"); you may not use this file except in compliance
9    * with the License.  You may obtain a copy of the License at
10   *
11   *     http://www.apache.org/licenses/LICENSE-2.0
12   *
13   * Unless required by applicable law or agreed to in writing, software
14   * distributed under the License is distributed on an "AS IS" BASIS,
15   * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
16   * See the License for the specific language governing permissions and
17   * limitations under the License.
18   */
19  package org.apache.hadoop.hbase;
20  
21  import org.apache.hadoop.classification.InterfaceAudience;
22  import org.apache.hadoop.conf.Configuration;
23  import org.apache.hadoop.hbase.client.HConnection;
24  import org.apache.hadoop.hbase.zookeeper.MetaTableLocator;
25  import org.apache.hadoop.hbase.zookeeper.ZooKeeperWatcher;
26  
27  /**
28   * Defines the set of shared functions implemented by HBase servers (Masters
29   * and RegionServers).
30   */
31  @InterfaceAudience.Private
32  public interface Server extends Abortable, Stoppable {
33    /**
34     * Gets the configuration object for this server.
35     */
36    Configuration getConfiguration();
37  
38    /**
39     * Gets the ZooKeeper instance for this server.
40     */
41    ZooKeeperWatcher getZooKeeper();
42  
43    /**
44     * Returns reference to wrapped short-circuit (i.e. local, bypassing RPC layer entirely)
45     * HConnection to this server, which may be used for miscellaneous needs.
46     *
47     * Important note: this method returns reference to connection which is managed
48     * by Server itself, so callers must NOT attempt to close connection obtained.
49     *
50     * See {@link org.apache.hadoop.hbase.client.ConnectionUtils#createShortCircuitHConnection}
51     * for details on short-circuit connections.
52     */
53    HConnection getShortCircuitConnection();
54  
55    /**
56     * Returns instance of {@link org.apache.hadoop.hbase.zookeeper.MetaTableLocator}
57     * running inside this server. This MetaServerLocator is started and stopped by server, clients
58     * shouldn't manage it's lifecycle.
59     * @return instance of {@link MetaTableLocator} associated with this server.
60     */
61    MetaTableLocator getMetaTableLocator();
62  
63    /**
64     * @return The unique server name for this server.
65     */
66    ServerName getServerName();
67  
68    /**
69     * Get CoordinatedStateManager instance for this server.
70     */
71    CoordinatedStateManager getCoordinatedStateManager();
72  }