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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.client.backoff;
19  
20  import org.apache.hadoop.hbase.ServerName;
21  import org.apache.hadoop.hbase.classification.InterfaceAudience;
22  import org.apache.hadoop.hbase.classification.InterfaceStability;
23  
24  /**
25   * Configurable policy for the amount of time a client should wait for a new request to the
26   * server when given the server load statistics.
27   * <p>
28   * Must have a single-argument constructor that takes a {@link org.apache.hadoop.conf.Configuration}
29   * </p>
30   */
31  @InterfaceAudience.Public
32  @InterfaceStability.Unstable
33  public interface ClientBackoffPolicy {
34  
35    public static final String BACKOFF_POLICY_CLASS =
36        "hbase.client.statistics.backoff-policy";
37  
38    /**
39     * @return the number of ms to wait on the client based on the
40     */
41    public long getBackoffTime(ServerName serverName, byte[] region, ServerStatistics stats);
42  }