1 /**
2 *
3 * Licensed to the Apache Software Foundation (ASF) under one
4 * or more contributor license agreements. See the NOTICE file
5 * distributed with this work for additional information
6 * regarding copyright ownership. The ASF licenses this file
7 * to you under the Apache License, Version 2.0 (the
8 * "License"); you may not use this file except in compliance
9 * with the License. You may obtain a copy of the License at
10 *
11 * http://www.apache.org/licenses/LICENSE-2.0
12 *
13 * Unless required by applicable law or agreed to in writing, software
14 * distributed under the License is distributed on an "AS IS" BASIS,
15 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
16 * See the License for the specific language governing permissions and
17 * limitations under the License.
18 */
19 package org.apache.hadoop.hbase.client;
20
21 import org.apache.hadoop.conf.Configuration;
22 import org.apache.hadoop.hbase.TableName;
23 import org.apache.hadoop.hbase.classification.InterfaceAudience;
24 import org.apache.hadoop.hbase.classification.InterfaceStability;
25
26 import java.io.Closeable;
27 import java.io.IOException;
28 import java.util.List;
29
30 /**
31 * <p>Used to communicate with a single HBase table similar to {@link Table} but meant for
32 * batched, asynchronous puts. Obtain an instance from a {@link Connection} and call
33 * {@link #close()} afterwards. Customizations can be applied to the {@code BufferedMutator} via
34 * the {@link BufferedMutatorParams}.
35 * </p>
36 *
37 * <p>Exception handling with asynchronously via the {@link BufferedMutator.ExceptionListener}.
38 * The default implementation is to throw the exception upon receipt. This behavior can be
39 * overridden with a custom implementation, provided as a parameter with
40 * {@link BufferedMutatorParams#listener(BufferedMutator.ExceptionListener)}.</p>
41 *
42 * <p>Map/Reduce jobs are good use cases for using {@code BufferedMutator}. Map/reduce jobs
43 * benefit from batching, but have no natural flush point. {@code BufferedMutator} receives the
44 * puts from the M/R job and will batch puts based on some heuristic, such as the accumulated size
45 * of the puts, and submit batches of puts asynchronously so that the M/R logic can continue
46 * without interruption.
47 * </p>
48 *
49 * <p>{@code BufferedMutator} can also be used on more exotic circumstances. Map/Reduce batch jobs
50 * will have a single {@code BufferedMutator} per thread. A single {@code BufferedMutator} can
51 * also be effectively used in high volume online systems to batch puts, with the caveat that
52 * extreme circumstances, such as JVM or machine failure, may cause some data loss.</p>
53 *
54 * <p>NOTE: This class replaces the functionality that used to be available via
55 * {@link HTableInterface#setAutoFlush(boolean)} set to {@code false}.
56 * </p>
57 *
58 * <p>See also the {@code BufferedMutatorExample} in the hbase-examples module.</p>
59 * @see ConnectionFactory
60 * @see Connection
61 * @since 1.0.0
62 */
63 @InterfaceAudience.Public
64 @InterfaceStability.Evolving
65 public interface BufferedMutator extends Closeable {
66 /**
67 * Gets the fully qualified table name instance of the table that this BufferedMutator writes to.
68 */
69 TableName getName();
70
71 /**
72 * Returns the {@link org.apache.hadoop.conf.Configuration} object used by this instance.
73 * <p>
74 * The reference returned is not a copy, so any change made to it will
75 * affect this instance.
76 */
77 Configuration getConfiguration();
78
79 /**
80 * Sends a {@link Mutation} to the table. The mutations will be buffered and sent over the
81 * wire as part of a batch. Currently only supports {@link Put} and {@link Delete} mutations.
82 *
83 * @param mutation The data to send.
84 * @throws IOException if a remote or network exception occurs.
85 */
86 void mutate(Mutation mutation) throws IOException;
87
88 /**
89 * Send some {@link Mutation}s to the table. The mutations will be buffered and sent over the
90 * wire as part of a batch. There is no guarantee of sending entire content of {@code mutations}
91 * in a single batch; it will be broken up according to the write buffer capacity.
92 *
93 * @param mutations The data to send.
94 * @throws IOException if a remote or network exception occurs.
95 */
96 void mutate(List<? extends Mutation> mutations) throws IOException;
97
98 /**
99 * Performs a {@link #flush()} and releases any resources held.
100 *
101 * @throws IOException if a remote or network exception occurs.
102 */
103 @Override
104 void close() throws IOException;
105
106 /**
107 * Executes all the buffered, asynchronous {@link Mutation} operations and waits until they
108 * are done.
109 *
110 * @throws IOException if a remote or network exception occurs.
111 */
112 void flush() throws IOException;
113
114 /**
115 * Returns the maximum size in bytes of the write buffer for this HTable.
116 * <p>
117 * The default value comes from the configuration parameter {@code hbase.client.write.buffer}.
118 * @return The size of the write buffer in bytes.
119 */
120 long getWriteBufferSize();
121
122 /**
123 * Listens for asynchronous exceptions on a {@link BufferedMutator}.
124 */
125 @InterfaceAudience.Public
126 @InterfaceStability.Evolving
127 interface ExceptionListener {
128 public void onException(RetriesExhaustedWithDetailsException exception,
129 BufferedMutator mutator) throws RetriesExhaustedWithDetailsException;
130 }
131 }