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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  package org.apache.hadoop.hbase.master;
19  
20  import java.io.IOException;
21  
22  import org.apache.hadoop.classification.InterfaceAudience;
23  import org.apache.hadoop.hbase.HRegionInfo;
24  import org.apache.hadoop.hbase.ServerName;
25  
26  /**
27   * Get notification of assignment events. The invocations are inline
28   * so make sure your implementation is fast else you'll slow hbase.
29   */
30  @InterfaceAudience.Private
31  public interface AssignmentListener {
32    /**
33     * The region was opened on the specified server.
34     * @param regionInfo The opened region.
35     * @param serverName The remote servers name.
36     */
37    void regionOpened(final HRegionInfo regionInfo, final ServerName serverName);
38  
39    /**
40     * The region was closed on the region server.
41     * @param regionInfo The closed region.
42     * @param serverName The remote servers name.
43     */
44    void regionClosed(final HRegionInfo regionInfo);
45  }