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,
13  * software distributed under the License is distributed on an
14  * "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY
15  * KIND, either express or implied.  See the License for the
16  * specific language governing permissions and limitations
17  * under the License.
18  */
19 package org.apache.hadoop.hbase.client;
20 
21 import org.apache.hadoop.hbase.classification.InterfaceAudience;
22 import org.apache.hadoop.hbase.classification.InterfaceStability;
23 
24 import java.io.IOException;
25 import java.util.Date;
26 import java.util.List;
27 
28 /**
29  * Exception thrown by HTable methods when an attempt to do something (like
30  * commit changes) fails after a bunch of retries.
31  */
32 @InterfaceAudience.Public
33 @InterfaceStability.Stable
34 public class RetriesExhaustedException extends IOException {
35   private static final long serialVersionUID = 1876775844L;
36 
RetriesExhaustedException(final String msg)37   public RetriesExhaustedException(final String msg) {
38     super(msg);
39   }
40 
RetriesExhaustedException(final String msg, final IOException e)41   public RetriesExhaustedException(final String msg, final IOException e) {
42     super(msg, e);
43   }
44 
45   /**
46    * Datastructure that allows adding more info around Throwable incident.
47    */
48   @InterfaceAudience.Private
49   public static class ThrowableWithExtraContext {
50     private final Throwable t;
51     private final long when;
52     private final String extras;
53 
ThrowableWithExtraContext(final Throwable t, final long when, final String extras)54     public ThrowableWithExtraContext(final Throwable t, final long when,
55         final String extras) {
56       this.t = t;
57       this.when = when;
58       this.extras = extras;
59     }
60 
61     @Override
toString()62     public String toString() {
63       return new Date(this.when).toString() + ", " + extras + ", " + t.toString();
64     }
65   }
66 
67   /**
68    * Create a new RetriesExhaustedException from the list of prior failures.
69    * @param callableVitals Details from the Callable we were using
70    * when we got this exception.
71    * @param numTries The number of tries we made
72    * @param exceptions List of exceptions that failed before giving up
73    */
RetriesExhaustedException(final String callableVitals, int numTries, List<Throwable> exceptions)74   public RetriesExhaustedException(final String callableVitals, int numTries,
75       List<Throwable> exceptions) {
76     super(getMessage(callableVitals, numTries, exceptions));
77   }
78 
79   /**
80    * Create a new RetriesExhaustedException from the list of prior failures.
81    * @param numTries
82    * @param exceptions List of exceptions that failed before giving up
83    */
84   @InterfaceAudience.Private
RetriesExhaustedException(final int numTries, final List<ThrowableWithExtraContext> exceptions)85   public RetriesExhaustedException(final int numTries,
86                                    final List<ThrowableWithExtraContext> exceptions) {
87     super(getMessage(numTries, exceptions),
88       exceptions.isEmpty()? null: exceptions.get(exceptions.size() - 1).t);
89   }
90 
getMessage(String callableVitals, int numTries, List<Throwable> exceptions)91   private static String getMessage(String callableVitals, int numTries,
92       List<Throwable> exceptions) {
93     StringBuilder buffer = new StringBuilder("Failed contacting ");
94     buffer.append(callableVitals);
95     buffer.append(" after ");
96     buffer.append(numTries + 1);
97     buffer.append(" attempts.\nExceptions:\n");
98     for (Throwable t : exceptions) {
99       buffer.append(t.toString());
100       buffer.append("\n");
101     }
102     return buffer.toString();
103   }
104 
getMessage(final int numTries, final List<ThrowableWithExtraContext> exceptions)105   private static String getMessage(final int numTries,
106       final List<ThrowableWithExtraContext> exceptions) {
107     StringBuilder buffer = new StringBuilder("Failed after attempts=");
108     buffer.append(numTries + 1);
109     buffer.append(", exceptions:\n");
110     for (ThrowableWithExtraContext t : exceptions) {
111       buffer.append(t.toString());
112       buffer.append("\n");
113     }
114     return buffer.toString();
115   }
116 }
117