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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;
19  
20  import org.apache.hadoop.conf.Configuration;
21  import org.apache.hadoop.hbase.HConstants;
22  import org.apache.hadoop.hbase.classification.InterfaceAudience;
23  import org.apache.hadoop.hbase.util.ReflectionUtils;
24  
25  /**
26   * Factory to create an {@link RpcRetryingCaller}
27   */
28  @InterfaceAudience.Private
29  public class RpcRetryingCallerFactory {
30  
31    /** Configuration key for a custom {@link RpcRetryingCaller} */
32    public static final String CUSTOM_CALLER_CONF_KEY = "hbase.rpc.callerfactory.class";
33    protected final Configuration conf;
34    private final long pause;
35    private final int retries;
36    private final int startLogErrorsCnt;
37    private final boolean enableBackPressure;
38    private ServerStatisticTracker stats;
39  
40    public RpcRetryingCallerFactory(Configuration conf) {
41      this(conf, null);
42    }
43  
44    public RpcRetryingCallerFactory(Configuration conf, ServerStatisticTracker stats) {
45      this.conf = conf;
46      this.stats = stats;
47      pause = conf.getLong(HConstants.HBASE_CLIENT_PAUSE,
48          HConstants.DEFAULT_HBASE_CLIENT_PAUSE);
49      retries = conf.getInt(HConstants.HBASE_CLIENT_RETRIES_NUMBER,
50          HConstants.DEFAULT_HBASE_CLIENT_RETRIES_NUMBER);
51      startLogErrorsCnt = conf.getInt(AsyncProcess.START_LOG_ERRORS_AFTER_COUNT_KEY,
52          AsyncProcess.DEFAULT_START_LOG_ERRORS_AFTER_COUNT);
53      enableBackPressure = conf.getBoolean(HConstants.ENABLE_CLIENT_BACKPRESSURE,
54        HConstants.DEFAULT_ENABLE_CLIENT_BACKPRESSURE);
55    }
56  
57    /**
58     * Set the tracker that should be used for tracking statistics about the server
59     */
60    public void setStatisticTracker(ServerStatisticTracker statisticTracker) {
61      this.stats = statisticTracker;
62    }
63  
64    public <T> RpcRetryingCaller<T> newCaller() {
65      // We store the values in the factory instance. This way, constructing new objects
66      //  is cheap as it does not require parsing a complex structure.
67      RpcRetryingCaller<T> caller;
68      if (enableBackPressure && this.stats != null) {
69        caller = new StatsTrackingRpcRetryingCaller<T>(pause, retries, startLogErrorsCnt,
70          this.stats);
71      } else {
72        caller = new RpcRetryingCaller<T>(pause, retries, startLogErrorsCnt);
73      }
74      return caller;
75    }
76  
77    public static RpcRetryingCallerFactory instantiate(Configuration configuration,
78        ServerStatisticTracker stats) {
79      String clazzName = RpcRetryingCallerFactory.class.getName();
80      String rpcCallerFactoryClazz =
81          configuration.get(RpcRetryingCallerFactory.CUSTOM_CALLER_CONF_KEY, clazzName);
82      if (rpcCallerFactoryClazz.equals(clazzName)) {
83        return new RpcRetryingCallerFactory(configuration, stats);
84      }
85      try {
86        return ReflectionUtils.instantiateWithCustomCtor(rpcCallerFactoryClazz,
87          new Class[] { Configuration.class, ServerStatisticTracker.class },
88          new Object[] { configuration, stats });
89      } catch (UnsupportedOperationException e) {
90        return ReflectionUtils.instantiateWithCustomCtor(rpcCallerFactoryClazz,
91          new Class[] { Configuration.class },
92          new Object[] { configuration });
93      }
94    }
95  }