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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.hbase.classification.InterfaceAudience;
21  import org.apache.hadoop.conf.Configuration;
22  import org.apache.hadoop.hbase.HConstants;
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 RetryingCallerInterceptor interceptor;
37    private final int startLogErrorsCnt;
38    private final boolean enableBackPressure;
39    private ServerStatisticTracker stats;
40  
41    public RpcRetryingCallerFactory(Configuration conf) {
42      this(conf, RetryingCallerInterceptorFactory.NO_OP_INTERCEPTOR);
43    }
44    
45    public RpcRetryingCallerFactory(Configuration conf, RetryingCallerInterceptor interceptor) {
46      this.conf = conf;
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      this.interceptor = interceptor;
54      enableBackPressure = conf.getBoolean(HConstants.ENABLE_CLIENT_BACKPRESSURE,
55          HConstants.DEFAULT_ENABLE_CLIENT_BACKPRESSURE);
56    }
57  
58    /**
59     * Set the tracker that should be used for tracking statistics about the server
60     */
61    public void setStatisticTracker(ServerStatisticTracker statisticTracker) {
62      this.stats = statisticTracker;
63    }
64  
65    public <T> RpcRetryingCaller<T> newCaller() {
66      // We store the values in the factory instance. This way, constructing new objects
67      //  is cheap as it does not require parsing a complex structure.
68      RpcRetryingCaller<T> caller = new RpcRetryingCaller<T>(pause, retries, interceptor,
69          startLogErrorsCnt);
70  
71      // wrap it with stats, if we are tracking them
72      if (enableBackPressure && this.stats != null) {
73        caller = new StatsTrackingRpcRetryingCaller<T>(pause, retries, interceptor,
74            startLogErrorsCnt, stats);
75      }
76  
77      return caller;
78    }
79  
80    public static RpcRetryingCallerFactory instantiate(Configuration configuration) {
81      return instantiate(configuration, RetryingCallerInterceptorFactory.NO_OP_INTERCEPTOR, null);
82    }
83  
84    public static RpcRetryingCallerFactory instantiate(Configuration configuration,
85        ServerStatisticTracker stats) {
86      return instantiate(configuration, RetryingCallerInterceptorFactory.NO_OP_INTERCEPTOR, stats);
87    }
88  
89    public static RpcRetryingCallerFactory instantiate(Configuration configuration,
90        RetryingCallerInterceptor interceptor, ServerStatisticTracker stats) {
91      String clazzName = RpcRetryingCallerFactory.class.getName();
92      String rpcCallerFactoryClazz =
93          configuration.get(RpcRetryingCallerFactory.CUSTOM_CALLER_CONF_KEY, clazzName);
94      RpcRetryingCallerFactory factory;
95      if (rpcCallerFactoryClazz.equals(clazzName)) {
96        factory = new RpcRetryingCallerFactory(configuration, interceptor);
97      } else {
98        factory = ReflectionUtils.instantiateWithCustomCtor(
99            rpcCallerFactoryClazz, new Class[] { Configuration.class },
100           new Object[] { configuration });
101     }
102 
103     // setting for backwards compat with existing caller factories, rather than in the ctor
104     factory.setStatisticTracker(stats);
105     return factory;
106   }
107 }