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.tool;
20
21 import org.apache.commons.logging.Log;
22 import org.apache.commons.logging.LogFactory;
23 import org.apache.hadoop.hbase.HConstants;
24 import org.apache.hadoop.hbase.client.Mutation;
25 import org.apache.hadoop.hbase.coprocessor.BaseRegionObserver;
26 import org.apache.hadoop.hbase.coprocessor.ObserverContext;
27 import org.apache.hadoop.hbase.coprocessor.RegionCoprocessorEnvironment;
28 import org.apache.hadoop.hbase.regionserver.MiniBatchOperationInProgress;
29 import org.apache.hadoop.hbase.regionserver.OperationStatus;
30
31 import java.io.IOException;
32 import java.util.concurrent.atomic.AtomicLong;
33
34 /**
35 * This coprocessor 'shallows' all the writes. It allows to test a pure
36 * write workload, going through all the communication layers.
37 * The reads will work as well, but they as we never write, they will always always
38 * return an empty structure. The WAL is also skipped.
39 * Obviously, the region will never be split automatically. It's up to the user
40 * to split and move it.
41 * <p/>
42 * For a table created like this:
43 * create 'usertable', {NAME => 'f1', VERSIONS => 1}
44 * <p/>
45 * You can then add the coprocessor with this command:
46 * alter 'usertable', 'coprocessor' => '|org.apache.hadoop.hbase.tool.WriteSinkCoprocessor|'
47 * <p/>
48 * And then
49 * put 'usertable', 'f1', 'f1', 'f1'
50 * <p/>
51 * scan 'usertable'
52 * Will return:
53 * 0 row(s) in 0.0050 seconds
54 * <p/>
55 */
56 public class WriteSinkCoprocessor extends BaseRegionObserver {
57 private static final Log LOG = LogFactory.getLog(WriteSinkCoprocessor.class);
58 private final AtomicLong ops = new AtomicLong();
59 private String regionName;
60
61 @Override
62 public void preOpen(ObserverContext<RegionCoprocessorEnvironment> e) throws IOException {
63 regionName = e.getEnvironment().getRegion().getRegionInfo().getRegionNameAsString();
64 }
65
66
67 @Override
68 public void preBatchMutate(final ObserverContext<RegionCoprocessorEnvironment> c,
69 final MiniBatchOperationInProgress<Mutation> miniBatchOp)
70 throws IOException {
71 if (ops.incrementAndGet() % 20000 == 0) {
72 LOG.info("Wrote " + ops.get() + " times in region " + regionName);
73 }
74
75 for (int i = 0; i < miniBatchOp.size(); i++) {
76 miniBatchOp.setOperationStatus(i,
77 new OperationStatus(HConstants.OperationStatusCode.SUCCESS));
78 }
79 c.bypass();
80 }
81 }