Java tutorial
/** * Licensed to the Apache Software Foundation (ASF) under one * or more contributor license agreements. See the NOTICE file * distributed with this work for additional information * regarding copyright ownership. The ASF licenses this file * to you under the Apache License, Version 2.0 (the * "License"); you may not use this file except in compliance * with the License. You may obtain a copy of the License at * * http://www.apache.org/licenses/LICENSE-2.0 * * Unless required by applicable law or agreed to in writing, software * distributed under the License is distributed on an "AS IS" BASIS, * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. * See the License for the specific language governing permissions and * limitations under the License. */ package org.apache.hadoop.hbase.mapreduce; import static org.junit.Assert.assertEquals; import static org.junit.Assert.assertFalse; import static org.junit.Assert.assertTrue; import java.util.List; import java.util.concurrent.atomic.AtomicLong; import org.apache.commons.logging.Log; import org.apache.commons.logging.LogFactory; import org.apache.hadoop.conf.Configuration; import org.apache.hadoop.fs.FileStatus; import org.apache.hadoop.fs.FileSystem; import org.apache.hadoop.fs.Path; import org.apache.hadoop.hbase.TableName; import org.apache.hadoop.hbase.HBaseTestingUtility; import org.apache.hadoop.hbase.HColumnDescriptor; import org.apache.hadoop.hbase.HConstants; import org.apache.hadoop.hbase.HRegionInfo; import org.apache.hadoop.hbase.HTableDescriptor; import org.apache.hadoop.hbase.KeyValue; import org.apache.hadoop.hbase.MediumTests; import org.apache.hadoop.hbase.mapreduce.HLogInputFormat.HLogRecordReader; import org.apache.hadoop.hbase.regionserver.wal.HLog; import org.apache.hadoop.hbase.regionserver.wal.HLogFactory; import org.apache.hadoop.hbase.regionserver.wal.WALEdit; import org.apache.hadoop.hbase.util.Bytes; import org.apache.hadoop.mapreduce.InputSplit; import org.apache.hadoop.mapreduce.MapReduceTestUtil; import org.junit.AfterClass; import org.junit.Before; import org.junit.BeforeClass; import org.junit.Test; import org.junit.experimental.categories.Category; /** * JUnit tests for the HLogRecordReader */ @Category(MediumTests.class) public class TestHLogRecordReader { private final Log LOG = LogFactory.getLog(getClass()); private final static HBaseTestingUtility TEST_UTIL = new HBaseTestingUtility(); private static Configuration conf; private static FileSystem fs; private static Path hbaseDir; private static final TableName tableName = TableName.valueOf(getName()); private static final byte[] rowName = tableName.getName(); private static final HRegionInfo info = new HRegionInfo(tableName, Bytes.toBytes(""), Bytes.toBytes(""), false); private static final byte[] family = Bytes.toBytes("column"); private static final byte[] value = Bytes.toBytes("value"); private static HTableDescriptor htd; private static Path logDir; private static String logName; private static String getName() { return "TestHLogRecordReader"; } @Before public void setUp() throws Exception { FileStatus[] entries = fs.listStatus(hbaseDir); for (FileStatus dir : entries) { fs.delete(dir.getPath(), true); } } @BeforeClass public static void setUpBeforeClass() throws Exception { // Make block sizes small. conf = TEST_UTIL.getConfiguration(); conf.setInt("dfs.blocksize", 1024 * 1024); conf.setInt("dfs.replication", 1); TEST_UTIL.startMiniDFSCluster(1); conf = TEST_UTIL.getConfiguration(); fs = TEST_UTIL.getDFSCluster().getFileSystem(); hbaseDir = TEST_UTIL.createRootDir(); logName = HConstants.HREGION_LOGDIR_NAME; logDir = new Path(hbaseDir, logName); htd = new HTableDescriptor(tableName); htd.addFamily(new HColumnDescriptor(family)); } @AfterClass public static void tearDownAfterClass() throws Exception { TEST_UTIL.shutdownMiniCluster(); } /** * Test partial reads from the log based on passed time range * @throws Exception */ @Test public void testPartialRead() throws Exception { HLog log = HLogFactory.createHLog(fs, hbaseDir, logName, conf); // This test depends on timestamp being millisecond based and the filename of the WAL also // being millisecond based. long ts = System.currentTimeMillis(); WALEdit edit = new WALEdit(); final AtomicLong sequenceId = new AtomicLong(0); edit.add(new KeyValue(rowName, family, Bytes.toBytes("1"), ts, value)); log.append(info, tableName, edit, ts, htd, sequenceId); edit = new WALEdit(); edit.add(new KeyValue(rowName, family, Bytes.toBytes("2"), ts + 1, value)); log.append(info, tableName, edit, ts + 1, htd, sequenceId); LOG.info("Before 1st WAL roll " + log.getFilenum()); log.rollWriter(); LOG.info("Past 1st WAL roll " + log.getFilenum()); Thread.sleep(1); long ts1 = System.currentTimeMillis(); edit = new WALEdit(); edit.add(new KeyValue(rowName, family, Bytes.toBytes("3"), ts1 + 1, value)); log.append(info, tableName, edit, ts1 + 1, htd, sequenceId); edit = new WALEdit(); edit.add(new KeyValue(rowName, family, Bytes.toBytes("4"), ts1 + 2, value)); log.append(info, tableName, edit, ts1 + 2, htd, sequenceId); log.close(); LOG.info("Closed WAL " + log.getFilenum()); HLogInputFormat input = new HLogInputFormat(); Configuration jobConf = new Configuration(conf); jobConf.set("mapreduce.input.fileinputformat.inputdir", logDir.toString()); jobConf.setLong(HLogInputFormat.END_TIME_KEY, ts); // only 1st file is considered, and only its 1st entry is used List<InputSplit> splits = input.getSplits(MapreduceTestingShim.createJobContext(jobConf)); assertEquals(1, splits.size()); testSplit(splits.get(0), Bytes.toBytes("1")); jobConf.setLong(HLogInputFormat.START_TIME_KEY, ts + 1); jobConf.setLong(HLogInputFormat.END_TIME_KEY, ts1 + 1); splits = input.getSplits(MapreduceTestingShim.createJobContext(jobConf)); // both files need to be considered assertEquals(2, splits.size()); // only the 2nd entry from the 1st file is used testSplit(splits.get(0), Bytes.toBytes("2")); // only the 1nd entry from the 2nd file is used testSplit(splits.get(1), Bytes.toBytes("3")); } /** * Test basic functionality * @throws Exception */ @Test public void testHLogRecordReader() throws Exception { HLog log = HLogFactory.createHLog(fs, hbaseDir, logName, conf); byte[] value = Bytes.toBytes("value"); final AtomicLong sequenceId = new AtomicLong(0); WALEdit edit = new WALEdit(); edit.add(new KeyValue(rowName, family, Bytes.toBytes("1"), System.currentTimeMillis(), value)); log.append(info, tableName, edit, System.currentTimeMillis(), htd, sequenceId); Thread.sleep(1); // make sure 2nd log gets a later timestamp long secondTs = System.currentTimeMillis(); log.rollWriter(); edit = new WALEdit(); edit.add(new KeyValue(rowName, family, Bytes.toBytes("2"), System.currentTimeMillis(), value)); log.append(info, tableName, edit, System.currentTimeMillis(), htd, sequenceId); log.close(); long thirdTs = System.currentTimeMillis(); // should have 2 log files now HLogInputFormat input = new HLogInputFormat(); Configuration jobConf = new Configuration(conf); jobConf.set("mapreduce.input.fileinputformat.inputdir", logDir.toString()); // make sure both logs are found List<InputSplit> splits = input.getSplits(MapreduceTestingShim.createJobContext(jobConf)); assertEquals(2, splits.size()); // should return exactly one KV testSplit(splits.get(0), Bytes.toBytes("1")); // same for the 2nd split testSplit(splits.get(1), Bytes.toBytes("2")); // now test basic time ranges: // set an endtime, the 2nd log file can be ignored completely. jobConf.setLong(HLogInputFormat.END_TIME_KEY, secondTs - 1); splits = input.getSplits(MapreduceTestingShim.createJobContext(jobConf)); assertEquals(1, splits.size()); testSplit(splits.get(0), Bytes.toBytes("1")); // now set a start time jobConf.setLong(HLogInputFormat.END_TIME_KEY, Long.MAX_VALUE); jobConf.setLong(HLogInputFormat.START_TIME_KEY, thirdTs); splits = input.getSplits(MapreduceTestingShim.createJobContext(jobConf)); // both logs need to be considered assertEquals(2, splits.size()); // but both readers skip all edits testSplit(splits.get(0)); testSplit(splits.get(1)); } /** * Create a new reader from the split, and match the edits against the passed columns. */ private void testSplit(InputSplit split, byte[]... columns) throws Exception { HLogRecordReader reader = new HLogRecordReader(); reader.initialize(split, MapReduceTestUtil.createDummyMapTaskAttemptContext(conf)); for (byte[] column : columns) { assertTrue(reader.nextKeyValue()); KeyValue kv = reader.getCurrentValue().getKeyValues().get(0); if (!Bytes.equals(column, kv.getQualifier())) { assertTrue("expected [" + Bytes.toString(column) + "], actual [" + Bytes.toString(kv.getQualifier()) + "]", false); } } assertFalse(reader.nextKeyValue()); reader.close(); } }