1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18 package org.apache.hadoop.hbase.mapreduce;
19
20 import java.io.File;
21 import java.io.IOException;
22 import java.util.Iterator;
23 import java.util.Map;
24 import java.util.NavigableMap;
25
26 import org.apache.commons.logging.Log;
27 import org.apache.commons.logging.LogFactory;
28 import org.apache.hadoop.conf.Configuration;
29 import org.apache.hadoop.fs.FileUtil;
30 import org.apache.hadoop.fs.Path;
31 import org.apache.hadoop.hbase.*;
32 import org.apache.hadoop.hbase.client.HTable;
33 import org.apache.hadoop.hbase.client.Put;
34 import org.apache.hadoop.hbase.client.Result;
35 import org.apache.hadoop.hbase.client.ResultScanner;
36 import org.apache.hadoop.hbase.client.Scan;
37 import org.apache.hadoop.hbase.io.ImmutableBytesWritable;
38 import org.apache.hadoop.hbase.util.Bytes;
39 import org.apache.hadoop.mapreduce.Job;
40 import org.apache.hadoop.mapreduce.lib.output.FileOutputFormat;
41 import org.junit.AfterClass;
42 import org.junit.BeforeClass;
43 import org.junit.Test;
44 import org.junit.experimental.categories.Category;
45
46 import static org.junit.Assert.fail;
47 import static org.junit.Assert.assertTrue;
48
49
50
51
52
53
54 @Category(LargeTests.class)
55 public class TestMultithreadedTableMapper {
56 private static final Log LOG = LogFactory.getLog(TestMultithreadedTableMapper.class);
57 private static final HBaseTestingUtility UTIL =
58 new HBaseTestingUtility();
59 static final byte[] MULTI_REGION_TABLE_NAME = Bytes.toBytes("mrtest");
60 static final byte[] INPUT_FAMILY = Bytes.toBytes("contents");
61 static final byte[] OUTPUT_FAMILY = Bytes.toBytes("text");
62 static final int NUMBER_OF_THREADS = 10;
63
64 @BeforeClass
65 public static void beforeClass() throws Exception {
66 UTIL.startMiniCluster();
67 HTable table = UTIL.createTable(MULTI_REGION_TABLE_NAME, new byte[][] {INPUT_FAMILY, OUTPUT_FAMILY});
68 UTIL.createMultiRegions(table, INPUT_FAMILY);
69 UTIL.loadTable(table, INPUT_FAMILY, false);
70 UTIL.startMiniMapReduceCluster();
71 }
72
73 @AfterClass
74 public static void afterClass() throws Exception {
75 UTIL.shutdownMiniMapReduceCluster();
76 UTIL.shutdownMiniCluster();
77 }
78
79
80
81
82 public static class ProcessContentsMapper
83 extends TableMapper<ImmutableBytesWritable, Put> {
84
85
86
87
88
89
90
91
92
93 public void map(ImmutableBytesWritable key, Result value,
94 Context context)
95 throws IOException, InterruptedException {
96 if (value.size() != 1) {
97 throw new IOException("There should only be one input column");
98 }
99 Map<byte[], NavigableMap<byte[], NavigableMap<Long, byte[]>>>
100 cf = value.getMap();
101 if(!cf.containsKey(INPUT_FAMILY)) {
102 throw new IOException("Wrong input columns. Missing: '" +
103 Bytes.toString(INPUT_FAMILY) + "'.");
104 }
105
106 String originalValue = Bytes.toString(value.getValue(INPUT_FAMILY, null));
107 StringBuilder newValue = new StringBuilder(originalValue);
108 newValue.reverse();
109
110 Put outval = new Put(key.get());
111 outval.add(OUTPUT_FAMILY, null, Bytes.toBytes(newValue.toString()));
112 context.write(key, outval);
113 }
114 }
115
116
117
118
119
120
121
122 @Test
123 public void testMultithreadedTableMapper()
124 throws IOException, InterruptedException, ClassNotFoundException {
125 runTestOnTable(new HTable(new Configuration(UTIL.getConfiguration()),
126 MULTI_REGION_TABLE_NAME));
127 }
128
129 private void runTestOnTable(HTable table)
130 throws IOException, InterruptedException, ClassNotFoundException {
131 Job job = null;
132 try {
133 LOG.info("Before map/reduce startup");
134 job = new Job(table.getConfiguration(), "process column contents");
135 job.setNumReduceTasks(1);
136 Scan scan = new Scan();
137 scan.addFamily(INPUT_FAMILY);
138 TableMapReduceUtil.initTableMapperJob(
139 Bytes.toString(table.getTableName()), scan,
140 MultithreadedTableMapper.class, ImmutableBytesWritable.class,
141 Put.class, job);
142 MultithreadedTableMapper.setMapperClass(job, ProcessContentsMapper.class);
143 MultithreadedTableMapper.setNumberOfThreads(job, NUMBER_OF_THREADS);
144 TableMapReduceUtil.initTableReducerJob(
145 Bytes.toString(table.getTableName()),
146 IdentityTableReducer.class, job);
147 FileOutputFormat.setOutputPath(job, new Path("test"));
148 LOG.info("Started " + Bytes.toString(table.getTableName()));
149 assertTrue(job.waitForCompletion(true));
150 LOG.info("After map/reduce completion");
151
152 verify(Bytes.toString(table.getTableName()));
153 } finally {
154 table.close();
155 if (job != null) {
156 FileUtil.fullyDelete(
157 new File(job.getConfiguration().get("hadoop.tmp.dir")));
158 }
159 }
160 }
161
162 private void verify(String tableName) throws IOException {
163 HTable table = new HTable(new Configuration(UTIL.getConfiguration()), tableName);
164 boolean verified = false;
165 long pause = UTIL.getConfiguration().getLong("hbase.client.pause", 5 * 1000);
166 int numRetries = UTIL.getConfiguration().getInt(HConstants.HBASE_CLIENT_RETRIES_NUMBER, 5);
167 for (int i = 0; i < numRetries; i++) {
168 try {
169 LOG.info("Verification attempt #" + i);
170 verifyAttempt(table);
171 verified = true;
172 break;
173 } catch (NullPointerException e) {
174
175
176 LOG.debug("Verification attempt failed: " + e.getMessage());
177 }
178 try {
179 Thread.sleep(pause);
180 } catch (InterruptedException e) {
181
182 }
183 }
184 assertTrue(verified);
185 table.close();
186 }
187
188
189
190
191
192
193
194
195
196 private void verifyAttempt(final HTable table)
197 throws IOException, NullPointerException {
198 Scan scan = new Scan();
199 scan.addFamily(INPUT_FAMILY);
200 scan.addFamily(OUTPUT_FAMILY);
201 ResultScanner scanner = table.getScanner(scan);
202 try {
203 Iterator<Result> itr = scanner.iterator();
204 assertTrue(itr.hasNext());
205 while(itr.hasNext()) {
206 Result r = itr.next();
207 if (LOG.isDebugEnabled()) {
208 if (r.size() > 2 ) {
209 throw new IOException("Too many results, expected 2 got " +
210 r.size());
211 }
212 }
213 byte[] firstValue = null;
214 byte[] secondValue = null;
215 int count = 0;
216 for(Cell kv : r.listCells()) {
217 if (count == 0) {
218 firstValue = CellUtil.cloneValue(kv);
219 }else if (count == 1) {
220 secondValue = CellUtil.cloneValue(kv);
221 }else if (count == 2) {
222 break;
223 }
224 count++;
225 }
226 String first = "";
227 if (firstValue == null) {
228 throw new NullPointerException(Bytes.toString(r.getRow()) +
229 ": first value is null");
230 }
231 first = Bytes.toString(firstValue);
232 String second = "";
233 if (secondValue == null) {
234 throw new NullPointerException(Bytes.toString(r.getRow()) +
235 ": second value is null");
236 }
237 byte[] secondReversed = new byte[secondValue.length];
238 for (int i = 0, j = secondValue.length - 1; j >= 0; j--, i++) {
239 secondReversed[i] = secondValue[j];
240 }
241 second = Bytes.toString(secondReversed);
242 if (first.compareTo(second) != 0) {
243 if (LOG.isDebugEnabled()) {
244 LOG.debug("second key is not the reverse of first. row=" +
245 Bytes.toStringBinary(r.getRow()) + ", first value=" + first +
246 ", second value=" + second);
247 }
248 fail();
249 }
250 }
251 } finally {
252 scanner.close();
253 }
254 }
255
256 }
257