hbase-server/src/test/java/org/apache/hadoop/hbase/wal/TestFSHLogProvider.java - hbase - Git at Google

 /**
  * 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.wal;

 import static org.junit.Assert.assertEquals;
 import static org.junit.Assert.assertFalse;
 import static org.junit.Assert.assertNull;
 import static org.junit.Assert.assertTrue;

 import java.io.IOException;
 import java.util.HashSet;
 import java.util.NavigableMap;
 import java.util.Set;
 import java.util.TreeMap;
 import java.util.concurrent.ThreadLocalRandom;
 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.HBaseClassTestRule;
 import org.apache.hadoop.hbase.HBaseTestingUtility;
 import org.apache.hadoop.hbase.HConstants;
 import org.apache.hadoop.hbase.KeyValue;
 import org.apache.hadoop.hbase.ServerName;
 import org.apache.hadoop.hbase.TableName;
 import org.apache.hadoop.hbase.client.ColumnFamilyDescriptorBuilder;
 import org.apache.hadoop.hbase.client.RegionInfo;
 import org.apache.hadoop.hbase.client.RegionInfoBuilder;
 import org.apache.hadoop.hbase.client.TableDescriptor;
 import org.apache.hadoop.hbase.client.TableDescriptorBuilder;
 import org.apache.hadoop.hbase.regionserver.MultiVersionConcurrencyControl;
 import org.apache.hadoop.hbase.testclassification.MediumTests;
 import org.apache.hadoop.hbase.testclassification.RegionServerTests;
 import org.apache.hadoop.hbase.util.Bytes;
 import org.apache.hadoop.hbase.util.CommonFSUtils;
 import org.apache.hadoop.hbase.util.EnvironmentEdgeManager;
 import org.junit.AfterClass;
 import org.junit.Before;
 import org.junit.BeforeClass;
 import org.junit.ClassRule;
 import org.junit.Rule;
 import org.junit.Test;
 import org.junit.experimental.categories.Category;
 import org.junit.rules.TestName;
 import org.slf4j.Logger;
 import org.slf4j.LoggerFactory;

 @Category({RegionServerTests.class, MediumTests.class})
 public class TestFSHLogProvider {

   @ClassRule
   public static final HBaseClassTestRule CLASS_RULE =
       HBaseClassTestRule.forClass(TestFSHLogProvider.class);

   private static final Logger LOG = LoggerFactory.getLogger(TestFSHLogProvider.class);

   private static Configuration conf;
   private static FileSystem fs;
   private final static HBaseTestingUtility TEST_UTIL = new HBaseTestingUtility();
   private MultiVersionConcurrencyControl mvcc;

   @Rule
   public final TestName currentTest = new TestName();

   @Before
   public void setUp() throws Exception {
     mvcc = new MultiVersionConcurrencyControl();
     FileStatus[] entries = fs.listStatus(new Path("/"));
     for (FileStatus dir : entries) {
       fs.delete(dir.getPath(), true);
     }
   }

   @BeforeClass
   public static void setUpBeforeClass() throws Exception {
     // Make block sizes small.
     TEST_UTIL.getConfiguration().setInt("dfs.blocksize", 1024 * 1024);
     // quicker heartbeat interval for faster DN death notification
     TEST_UTIL.getConfiguration().setInt("dfs.namenode.heartbeat.recheck-interval", 5000);
     TEST_UTIL.getConfiguration().setInt("dfs.heartbeat.interval", 1);
     TEST_UTIL.getConfiguration().setInt("dfs.client.socket-timeout", 5000);

     // faster failover with cluster.shutdown();fs.close() idiom
     TEST_UTIL.getConfiguration()
         .setInt("hbase.ipc.client.connect.max.retries", 1);
     TEST_UTIL.getConfiguration().setInt(
         "dfs.client.block.recovery.retries", 1);
     TEST_UTIL.getConfiguration().setInt(
       "hbase.ipc.client.connection.maxidletime", 500);
     TEST_UTIL.startMiniDFSCluster(3);

     // Set up a working space for our tests.
     TEST_UTIL.createRootDir();
     conf = TEST_UTIL.getConfiguration();
     fs = TEST_UTIL.getDFSCluster().getFileSystem();
   }

   @AfterClass
   public static void tearDownAfterClass() throws Exception {
     TEST_UTIL.shutdownMiniCluster();
   }

   static String getName() {
     return "TestDefaultWALProvider";
   }

   @Test
   public void testGetServerNameFromWALDirectoryName() throws IOException {
     ServerName sn = ServerName.valueOf("hn", 450, 1398);
     String hl = CommonFSUtils.getRootDir(conf) + "/" +
         AbstractFSWALProvider.getWALDirectoryName(sn.toString());

     // Must not throw exception
     assertNull(AbstractFSWALProvider.getServerNameFromWALDirectoryName(conf, null));
     assertNull(AbstractFSWALProvider.getServerNameFromWALDirectoryName(conf,
       CommonFSUtils.getRootDir(conf).toUri().toString()));
     assertNull(AbstractFSWALProvider.getServerNameFromWALDirectoryName(conf, ""));
     assertNull(AbstractFSWALProvider.getServerNameFromWALDirectoryName(conf, "                  "));
     assertNull(AbstractFSWALProvider.getServerNameFromWALDirectoryName(conf, hl));
     assertNull(AbstractFSWALProvider.getServerNameFromWALDirectoryName(conf, hl + "qdf"));
     assertNull(AbstractFSWALProvider.getServerNameFromWALDirectoryName(conf, "sfqf" + hl + "qdf"));

     final String wals = "/WALs/";
     ServerName parsed = AbstractFSWALProvider.getServerNameFromWALDirectoryName(conf,
       CommonFSUtils.getRootDir(conf).toUri().toString() + wals + sn +
       "/localhost%2C32984%2C1343316388997.1343316390417");
     assertEquals("standard",  sn, parsed);

     parsed = AbstractFSWALProvider.getServerNameFromWALDirectoryName(conf, hl + "/qdf");
     assertEquals("subdir", sn, parsed);

     parsed = AbstractFSWALProvider.getServerNameFromWALDirectoryName(conf,
       CommonFSUtils.getRootDir(conf).toUri().toString() + wals + sn +
       "-splitting/localhost%3A57020.1340474893931");
     assertEquals("split", sn, parsed);
   }


   private void addEdits(WAL log, RegionInfo hri, TableDescriptor htd, int times,
       NavigableMap<byte[], Integer> scopes) throws IOException {
     final byte[] row = Bytes.toBytes("row");
     for (int i = 0; i < times; i++) {
       long timestamp = EnvironmentEdgeManager.currentTime();
       WALEdit cols = new WALEdit();
       cols.add(new KeyValue(row, row, row, timestamp, row));
       log.appendData(hri,
         getWalKey(hri.getEncodedNameAsBytes(), htd.getTableName(), timestamp, scopes), cols);
     }
     log.sync();
   }

   /**
    * used by TestDefaultWALProviderWithHLogKey
    * @param scopes
    */
   WALKeyImpl getWalKey(final byte[] info, final TableName tableName, final long timestamp,
       NavigableMap<byte[], Integer> scopes) {
     return new WALKeyImpl(info, tableName, timestamp, mvcc, scopes);
   }

   /**
    * helper method to simulate region flush for a WAL.
    * @param wal
    * @param regionEncodedName
    */
   protected void flushRegion(WAL wal, byte[] regionEncodedName, Set<byte[]> flushedFamilyNames) {
     wal.startCacheFlush(regionEncodedName, flushedFamilyNames);
     wal.completeCacheFlush(regionEncodedName, HConstants.NO_SEQNUM);
   }

   @Test
   public void testLogCleaning() throws Exception {
     LOG.info(currentTest.getMethodName());
     TableDescriptor htd =
         TableDescriptorBuilder.newBuilder(TableName.valueOf(currentTest.getMethodName()))
             .setColumnFamily(ColumnFamilyDescriptorBuilder.of("row")).build();
     TableDescriptor htd2 =
         TableDescriptorBuilder.newBuilder(TableName.valueOf(currentTest.getMethodName() + "2"))
             .setColumnFamily(ColumnFamilyDescriptorBuilder.of("row")).build();
     NavigableMap<byte[], Integer> scopes1 = new TreeMap<>(Bytes.BYTES_COMPARATOR);
     for (byte[] fam : htd.getColumnFamilyNames()) {
       scopes1.put(fam, 0);
     }
     NavigableMap<byte[], Integer> scopes2 = new TreeMap<>(Bytes.BYTES_COMPARATOR);
     for (byte[] fam : htd2.getColumnFamilyNames()) {
       scopes2.put(fam, 0);
     }
     Configuration localConf = new Configuration(conf);
     localConf.set(WALFactory.WAL_PROVIDER, FSHLogProvider.class.getName());
     WALFactory wals = new WALFactory(localConf, currentTest.getMethodName());
     try {
       RegionInfo hri = RegionInfoBuilder.newBuilder(htd.getTableName()).build();
       RegionInfo hri2 = RegionInfoBuilder.newBuilder(htd2.getTableName()).build();
       // we want to mix edits from regions, so pick our own identifier.
       WAL log = wals.getWAL(null);

       // Add a single edit and make sure that rolling won't remove the file
       // Before HBASE-3198 it used to delete it
       addEdits(log, hri, htd, 1, scopes1);
       log.rollWriter();
       assertEquals(1, AbstractFSWALProvider.getNumRolledLogFiles(log));

       // See if there's anything wrong with more than 1 edit
       addEdits(log, hri, htd, 2, scopes1);
       log.rollWriter();
       assertEquals(2, FSHLogProvider.getNumRolledLogFiles(log));

       // Now mix edits from 2 regions, still no flushing
       addEdits(log, hri, htd, 1, scopes1);
       addEdits(log, hri2, htd2, 1, scopes2);
       addEdits(log, hri, htd, 1, scopes1);
       addEdits(log, hri2, htd2, 1, scopes2);
       log.rollWriter();
       assertEquals(3, AbstractFSWALProvider.getNumRolledLogFiles(log));

       // Flush the first region, we expect to see the first two files getting
       // archived. We need to append something or writer won't be rolled.
       addEdits(log, hri2, htd2, 1, scopes2);
       log.startCacheFlush(hri.getEncodedNameAsBytes(), htd.getColumnFamilyNames());
       log.completeCacheFlush(hri.getEncodedNameAsBytes(), HConstants.NO_SEQNUM);
       log.rollWriter();
       int count = AbstractFSWALProvider.getNumRolledLogFiles(log);
       assertEquals(2, count);

       // Flush the second region, which removes all the remaining output files
       // since the oldest was completely flushed and the two others only contain
       // flush information
       addEdits(log, hri2, htd2, 1, scopes2);
       log.startCacheFlush(hri2.getEncodedNameAsBytes(), htd2.getColumnFamilyNames());
       log.completeCacheFlush(hri2.getEncodedNameAsBytes(), HConstants.NO_SEQNUM);
       log.rollWriter();
       assertEquals(0, AbstractFSWALProvider.getNumRolledLogFiles(log));
     } finally {
       if (wals != null) {
         wals.close();
       }
     }
   }

   /**
    * Tests wal archiving by adding data, doing flushing/rolling and checking we archive old logs
    * and also don't archive "live logs" (that is, a log with un-flushed entries).
    * <p>
    * This is what it does:
    * It creates two regions, and does a series of inserts along with log rolling.
    * Whenever a WAL is rolled, HLogBase checks previous wals for archiving. A wal is eligible for
    * archiving if for all the regions which have entries in that wal file, have flushed - past
    * their maximum sequence id in that wal file.
    * <p>
    * @throws IOException
    */
   @Test
   public void testWALArchiving() throws IOException {
     LOG.debug(currentTest.getMethodName());
     TableDescriptor table1 =
         TableDescriptorBuilder.newBuilder(TableName.valueOf(currentTest.getMethodName() + "1"))
             .setColumnFamily(ColumnFamilyDescriptorBuilder.of("row")).build();
     TableDescriptor table2 =
         TableDescriptorBuilder.newBuilder(TableName.valueOf(currentTest.getMethodName() + "2"))
             .setColumnFamily(ColumnFamilyDescriptorBuilder.of("row")).build();
     NavigableMap<byte[], Integer> scopes1 = new TreeMap<>(Bytes.BYTES_COMPARATOR);
     for (byte[] fam : table1.getColumnFamilyNames()) {
       scopes1.put(fam, 0);
     }
     NavigableMap<byte[], Integer> scopes2 = new TreeMap<>(Bytes.BYTES_COMPARATOR);
     for (byte[] fam : table2.getColumnFamilyNames()) {
       scopes2.put(fam, 0);
     }
     Configuration localConf = new Configuration(conf);
     localConf.set(WALFactory.WAL_PROVIDER, FSHLogProvider.class.getName());
     WALFactory wals = new WALFactory(localConf, currentTest.getMethodName());
     try {
       WAL wal = wals.getWAL(null);
       assertEquals(0, AbstractFSWALProvider.getNumRolledLogFiles(wal));
       RegionInfo hri1 = RegionInfoBuilder.newBuilder(table1.getTableName()).build();
       RegionInfo hri2 = RegionInfoBuilder.newBuilder(table2.getTableName()).build();
       // variables to mock region sequenceIds.
       // start with the testing logic: insert a waledit, and roll writer
       addEdits(wal, hri1, table1, 1, scopes1);
       wal.rollWriter();
       // assert that the wal is rolled
       assertEquals(1, AbstractFSWALProvider.getNumRolledLogFiles(wal));
       // add edits in the second wal file, and roll writer.
       addEdits(wal, hri1, table1, 1, scopes1);
       wal.rollWriter();
       // assert that the wal is rolled
       assertEquals(2, AbstractFSWALProvider.getNumRolledLogFiles(wal));
       // add a waledit to table1, and flush the region.
       addEdits(wal, hri1, table1, 3, scopes1);
       flushRegion(wal, hri1.getEncodedNameAsBytes(), table1.getColumnFamilyNames());
       // roll log; all old logs should be archived.
       wal.rollWriter();
       assertEquals(0, AbstractFSWALProvider.getNumRolledLogFiles(wal));
       // add an edit to table2, and roll writer
       addEdits(wal, hri2, table2, 1, scopes2);
       wal.rollWriter();
       assertEquals(1, AbstractFSWALProvider.getNumRolledLogFiles(wal));
       // add edits for table1, and roll writer
       addEdits(wal, hri1, table1, 2, scopes1);
       wal.rollWriter();
       assertEquals(2, AbstractFSWALProvider.getNumRolledLogFiles(wal));
       // add edits for table2, and flush hri1.
       addEdits(wal, hri2, table2, 2, scopes2);
       flushRegion(wal, hri1.getEncodedNameAsBytes(), table2.getColumnFamilyNames());
       // the log : region-sequenceId map is
       // log1: region2 (unflushed)
       // log2: region1 (flushed)
       // log3: region2 (unflushed)
       // roll the writer; log2 should be archived.
       wal.rollWriter();
       assertEquals(2, AbstractFSWALProvider.getNumRolledLogFiles(wal));
       // flush region2, and all logs should be archived.
       addEdits(wal, hri2, table2, 2, scopes2);
       flushRegion(wal, hri2.getEncodedNameAsBytes(), table2.getColumnFamilyNames());
       wal.rollWriter();
       assertEquals(0, AbstractFSWALProvider.getNumRolledLogFiles(wal));
     } finally {
       if (wals != null) {
         wals.close();
       }
     }
   }

   /**
    * Write to a log file with three concurrent threads and verifying all data is written.
    * @throws Exception
    */
   @Test
   public void testConcurrentWrites() throws Exception {
     // Run the WPE tool with three threads writing 3000 edits each concurrently.
     // When done, verify that all edits were written.
     int errCode = WALPerformanceEvaluation.
       innerMain(new Configuration(TEST_UTIL.getConfiguration()),
         new String [] {"-threads", "3", "-verify", "-noclosefs", "-iterations", "3000"});
     assertEquals(0, errCode);
   }

   /**
    * Ensure that we can use Set.add to deduplicate WALs
    */
   @Test
   public void setMembershipDedups() throws IOException {
     Configuration localConf = new Configuration(conf);
     localConf.set(WALFactory.WAL_PROVIDER, FSHLogProvider.class.getName());
     WALFactory wals = new WALFactory(localConf, currentTest.getMethodName());
     try {
       final Set<WAL> seen = new HashSet<>(1);
       assertTrue("first attempt to add WAL from default provider should work.",
         seen.add(wals.getWAL(null)));
       for (int i = 0; i < 1000; i++) {
         assertFalse(
           "default wal provider is only supposed to return a single wal, which should " +
             "compare as .equals itself.",
           seen.add(wals.getWAL(RegionInfoBuilder
               .newBuilder(TableName.valueOf("Table-" + ThreadLocalRandom.current().nextInt()))
               .build())));
       }
     } finally {
       wals.close();
     }
   }
 }
	/**
	* 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.wal;

	import static org.junit.Assert.assertEquals;
	import static org.junit.Assert.assertFalse;
	import static org.junit.Assert.assertNull;
	import static org.junit.Assert.assertTrue;

	import java.io.IOException;
	import java.util.HashSet;
	import java.util.NavigableMap;
	import java.util.Set;
	import java.util.TreeMap;
	import java.util.concurrent.ThreadLocalRandom;
	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.HBaseClassTestRule;
	import org.apache.hadoop.hbase.HBaseTestingUtility;
	import org.apache.hadoop.hbase.HConstants;
	import org.apache.hadoop.hbase.KeyValue;
	import org.apache.hadoop.hbase.ServerName;
	import org.apache.hadoop.hbase.TableName;
	import org.apache.hadoop.hbase.client.ColumnFamilyDescriptorBuilder;
	import org.apache.hadoop.hbase.client.RegionInfo;
	import org.apache.hadoop.hbase.client.RegionInfoBuilder;
	import org.apache.hadoop.hbase.client.TableDescriptor;
	import org.apache.hadoop.hbase.client.TableDescriptorBuilder;
	import org.apache.hadoop.hbase.regionserver.MultiVersionConcurrencyControl;
	import org.apache.hadoop.hbase.testclassification.MediumTests;
	import org.apache.hadoop.hbase.testclassification.RegionServerTests;
	import org.apache.hadoop.hbase.util.Bytes;
	import org.apache.hadoop.hbase.util.CommonFSUtils;
	import org.apache.hadoop.hbase.util.EnvironmentEdgeManager;
	import org.junit.AfterClass;
	import org.junit.Before;
	import org.junit.BeforeClass;
	import org.junit.ClassRule;
	import org.junit.Rule;
	import org.junit.Test;
	import org.junit.experimental.categories.Category;
	import org.junit.rules.TestName;
	import org.slf4j.Logger;
	import org.slf4j.LoggerFactory;

	@Category({RegionServerTests.class, MediumTests.class})
	public class TestFSHLogProvider {

	@ClassRule
	public static final HBaseClassTestRule CLASS_RULE =
	HBaseClassTestRule.forClass(TestFSHLogProvider.class);

	private static final Logger LOG = LoggerFactory.getLogger(TestFSHLogProvider.class);

	private static Configuration conf;
	private static FileSystem fs;
	private final static HBaseTestingUtility TEST_UTIL = new HBaseTestingUtility();
	private MultiVersionConcurrencyControl mvcc;

	@Rule
	public final TestName currentTest = new TestName();

	@Before
	public void setUp() throws Exception {
	mvcc = new MultiVersionConcurrencyControl();
	FileStatus[] entries = fs.listStatus(new Path("/"));
	for (FileStatus dir : entries) {
	fs.delete(dir.getPath(), true);
	}
	}

	@BeforeClass
	public static void setUpBeforeClass() throws Exception {
	// Make block sizes small.
	TEST_UTIL.getConfiguration().setInt("dfs.blocksize", 1024 * 1024);
	// quicker heartbeat interval for faster DN death notification
	TEST_UTIL.getConfiguration().setInt("dfs.namenode.heartbeat.recheck-interval", 5000);
	TEST_UTIL.getConfiguration().setInt("dfs.heartbeat.interval", 1);
	TEST_UTIL.getConfiguration().setInt("dfs.client.socket-timeout", 5000);

	// faster failover with cluster.shutdown();fs.close() idiom
	TEST_UTIL.getConfiguration()
	.setInt("hbase.ipc.client.connect.max.retries", 1);
	TEST_UTIL.getConfiguration().setInt(
	"dfs.client.block.recovery.retries", 1);
	TEST_UTIL.getConfiguration().setInt(
	"hbase.ipc.client.connection.maxidletime", 500);
	TEST_UTIL.startMiniDFSCluster(3);

	// Set up a working space for our tests.
	TEST_UTIL.createRootDir();
	conf = TEST_UTIL.getConfiguration();
	fs = TEST_UTIL.getDFSCluster().getFileSystem();
	}

	@AfterClass
	public static void tearDownAfterClass() throws Exception {
	TEST_UTIL.shutdownMiniCluster();
	}

	static String getName() {
	return "TestDefaultWALProvider";
	}

	@Test
	public void testGetServerNameFromWALDirectoryName() throws IOException {
	ServerName sn = ServerName.valueOf("hn", 450, 1398);
	String hl = CommonFSUtils.getRootDir(conf) + "/" +
	AbstractFSWALProvider.getWALDirectoryName(sn.toString());

	// Must not throw exception
	assertNull(AbstractFSWALProvider.getServerNameFromWALDirectoryName(conf, null));
	assertNull(AbstractFSWALProvider.getServerNameFromWALDirectoryName(conf,
	CommonFSUtils.getRootDir(conf).toUri().toString()));
	assertNull(AbstractFSWALProvider.getServerNameFromWALDirectoryName(conf, ""));
	assertNull(AbstractFSWALProvider.getServerNameFromWALDirectoryName(conf, " "));
	assertNull(AbstractFSWALProvider.getServerNameFromWALDirectoryName(conf, hl));
	assertNull(AbstractFSWALProvider.getServerNameFromWALDirectoryName(conf, hl + "qdf"));
	assertNull(AbstractFSWALProvider.getServerNameFromWALDirectoryName(conf, "sfqf" + hl + "qdf"));

	final String wals = "/WALs/";
	ServerName parsed = AbstractFSWALProvider.getServerNameFromWALDirectoryName(conf,
	CommonFSUtils.getRootDir(conf).toUri().toString() + wals + sn +
	"/localhost%2C32984%2C1343316388997.1343316390417");
	assertEquals("standard", sn, parsed);

	parsed = AbstractFSWALProvider.getServerNameFromWALDirectoryName(conf, hl + "/qdf");
	assertEquals("subdir", sn, parsed);

	parsed = AbstractFSWALProvider.getServerNameFromWALDirectoryName(conf,
	CommonFSUtils.getRootDir(conf).toUri().toString() + wals + sn +
	"-splitting/localhost%3A57020.1340474893931");
	assertEquals("split", sn, parsed);
	}


	private void addEdits(WAL log, RegionInfo hri, TableDescriptor htd, int times,
	NavigableMap<byte[], Integer> scopes) throws IOException {
	final byte[] row = Bytes.toBytes("row");
	for (int i = 0; i < times; i++) {
	long timestamp = EnvironmentEdgeManager.currentTime();
	WALEdit cols = new WALEdit();
	cols.add(new KeyValue(row, row, row, timestamp, row));
	log.appendData(hri,
	getWalKey(hri.getEncodedNameAsBytes(), htd.getTableName(), timestamp, scopes), cols);
	}
	log.sync();
	}

	/**
	* used by TestDefaultWALProviderWithHLogKey
	* @param scopes
	*/
	WALKeyImpl getWalKey(final byte[] info, final TableName tableName, final long timestamp,
	NavigableMap<byte[], Integer> scopes) {
	return new WALKeyImpl(info, tableName, timestamp, mvcc, scopes);
	}

	/**
	* helper method to simulate region flush for a WAL.
	* @param wal
	* @param regionEncodedName
	*/
	protected void flushRegion(WAL wal, byte[] regionEncodedName, Set<byte[]> flushedFamilyNames) {
	wal.startCacheFlush(regionEncodedName, flushedFamilyNames);
	wal.completeCacheFlush(regionEncodedName, HConstants.NO_SEQNUM);
	}

	@Test
	public void testLogCleaning() throws Exception {
	LOG.info(currentTest.getMethodName());
	TableDescriptor htd =
	TableDescriptorBuilder.newBuilder(TableName.valueOf(currentTest.getMethodName()))
	.setColumnFamily(ColumnFamilyDescriptorBuilder.of("row")).build();
	TableDescriptor htd2 =
	TableDescriptorBuilder.newBuilder(TableName.valueOf(currentTest.getMethodName() + "2"))
	.setColumnFamily(ColumnFamilyDescriptorBuilder.of("row")).build();
	NavigableMap<byte[], Integer> scopes1 = new TreeMap<>(Bytes.BYTES_COMPARATOR);
	for (byte[] fam : htd.getColumnFamilyNames()) {
	scopes1.put(fam, 0);
	}
	NavigableMap<byte[], Integer> scopes2 = new TreeMap<>(Bytes.BYTES_COMPARATOR);
	for (byte[] fam : htd2.getColumnFamilyNames()) {
	scopes2.put(fam, 0);
	}
	Configuration localConf = new Configuration(conf);
	localConf.set(WALFactory.WAL_PROVIDER, FSHLogProvider.class.getName());
	WALFactory wals = new WALFactory(localConf, currentTest.getMethodName());
	try {
	RegionInfo hri = RegionInfoBuilder.newBuilder(htd.getTableName()).build();
	RegionInfo hri2 = RegionInfoBuilder.newBuilder(htd2.getTableName()).build();
	// we want to mix edits from regions, so pick our own identifier.
	WAL log = wals.getWAL(null);

	// Add a single edit and make sure that rolling won't remove the file
	// Before HBASE-3198 it used to delete it
	addEdits(log, hri, htd, 1, scopes1);
	log.rollWriter();
	assertEquals(1, AbstractFSWALProvider.getNumRolledLogFiles(log));

	// See if there's anything wrong with more than 1 edit
	addEdits(log, hri, htd, 2, scopes1);
	log.rollWriter();
	assertEquals(2, FSHLogProvider.getNumRolledLogFiles(log));

	// Now mix edits from 2 regions, still no flushing
	addEdits(log, hri, htd, 1, scopes1);
	addEdits(log, hri2, htd2, 1, scopes2);
	addEdits(log, hri, htd, 1, scopes1);
	addEdits(log, hri2, htd2, 1, scopes2);
	log.rollWriter();
	assertEquals(3, AbstractFSWALProvider.getNumRolledLogFiles(log));

	// Flush the first region, we expect to see the first two files getting
	// archived. We need to append something or writer won't be rolled.
	addEdits(log, hri2, htd2, 1, scopes2);
	log.startCacheFlush(hri.getEncodedNameAsBytes(), htd.getColumnFamilyNames());
	log.completeCacheFlush(hri.getEncodedNameAsBytes(), HConstants.NO_SEQNUM);
	log.rollWriter();
	int count = AbstractFSWALProvider.getNumRolledLogFiles(log);
	assertEquals(2, count);

	// Flush the second region, which removes all the remaining output files
	// since the oldest was completely flushed and the two others only contain
	// flush information
	addEdits(log, hri2, htd2, 1, scopes2);
	log.startCacheFlush(hri2.getEncodedNameAsBytes(), htd2.getColumnFamilyNames());
	log.completeCacheFlush(hri2.getEncodedNameAsBytes(), HConstants.NO_SEQNUM);
	log.rollWriter();
	assertEquals(0, AbstractFSWALProvider.getNumRolledLogFiles(log));
	} finally {
	if (wals != null) {
	wals.close();
	}
	}
	}

	/**
	* Tests wal archiving by adding data, doing flushing/rolling and checking we archive old logs
	* and also don't archive "live logs" (that is, a log with un-flushed entries).
	* <p>
	* This is what it does:
	* It creates two regions, and does a series of inserts along with log rolling.
	* Whenever a WAL is rolled, HLogBase checks previous wals for archiving. A wal is eligible for
	* archiving if for all the regions which have entries in that wal file, have flushed - past
	* their maximum sequence id in that wal file.
	* <p>
	* @throws IOException
	*/
	@Test
	public void testWALArchiving() throws IOException {
	LOG.debug(currentTest.getMethodName());
	TableDescriptor table1 =
	TableDescriptorBuilder.newBuilder(TableName.valueOf(currentTest.getMethodName() + "1"))
	.setColumnFamily(ColumnFamilyDescriptorBuilder.of("row")).build();
	TableDescriptor table2 =
	TableDescriptorBuilder.newBuilder(TableName.valueOf(currentTest.getMethodName() + "2"))
	.setColumnFamily(ColumnFamilyDescriptorBuilder.of("row")).build();
	NavigableMap<byte[], Integer> scopes1 = new TreeMap<>(Bytes.BYTES_COMPARATOR);
	for (byte[] fam : table1.getColumnFamilyNames()) {
	scopes1.put(fam, 0);
	}
	NavigableMap<byte[], Integer> scopes2 = new TreeMap<>(Bytes.BYTES_COMPARATOR);
	for (byte[] fam : table2.getColumnFamilyNames()) {
	scopes2.put(fam, 0);
	}
	Configuration localConf = new Configuration(conf);
	localConf.set(WALFactory.WAL_PROVIDER, FSHLogProvider.class.getName());
	WALFactory wals = new WALFactory(localConf, currentTest.getMethodName());
	try {
	WAL wal = wals.getWAL(null);
	assertEquals(0, AbstractFSWALProvider.getNumRolledLogFiles(wal));
	RegionInfo hri1 = RegionInfoBuilder.newBuilder(table1.getTableName()).build();
	RegionInfo hri2 = RegionInfoBuilder.newBuilder(table2.getTableName()).build();
	// variables to mock region sequenceIds.
	// start with the testing logic: insert a waledit, and roll writer
	addEdits(wal, hri1, table1, 1, scopes1);
	wal.rollWriter();
	// assert that the wal is rolled
	assertEquals(1, AbstractFSWALProvider.getNumRolledLogFiles(wal));
	// add edits in the second wal file, and roll writer.
	addEdits(wal, hri1, table1, 1, scopes1);
	wal.rollWriter();
	// assert that the wal is rolled
	assertEquals(2, AbstractFSWALProvider.getNumRolledLogFiles(wal));
	// add a waledit to table1, and flush the region.
	addEdits(wal, hri1, table1, 3, scopes1);
	flushRegion(wal, hri1.getEncodedNameAsBytes(), table1.getColumnFamilyNames());
	// roll log; all old logs should be archived.
	wal.rollWriter();
	assertEquals(0, AbstractFSWALProvider.getNumRolledLogFiles(wal));
	// add an edit to table2, and roll writer
	addEdits(wal, hri2, table2, 1, scopes2);
	wal.rollWriter();
	assertEquals(1, AbstractFSWALProvider.getNumRolledLogFiles(wal));
	// add edits for table1, and roll writer
	addEdits(wal, hri1, table1, 2, scopes1);
	wal.rollWriter();
	assertEquals(2, AbstractFSWALProvider.getNumRolledLogFiles(wal));
	// add edits for table2, and flush hri1.
	addEdits(wal, hri2, table2, 2, scopes2);
	flushRegion(wal, hri1.getEncodedNameAsBytes(), table2.getColumnFamilyNames());
	// the log : region-sequenceId map is
	// log1: region2 (unflushed)
	// log2: region1 (flushed)
	// log3: region2 (unflushed)
	// roll the writer; log2 should be archived.
	wal.rollWriter();
	assertEquals(2, AbstractFSWALProvider.getNumRolledLogFiles(wal));
	// flush region2, and all logs should be archived.
	addEdits(wal, hri2, table2, 2, scopes2);
	flushRegion(wal, hri2.getEncodedNameAsBytes(), table2.getColumnFamilyNames());
	wal.rollWriter();
	assertEquals(0, AbstractFSWALProvider.getNumRolledLogFiles(wal));
	} finally {
	if (wals != null) {
	wals.close();
	}
	}
	}

	/**
	* Write to a log file with three concurrent threads and verifying all data is written.
	* @throws Exception
	*/
	@Test
	public void testConcurrentWrites() throws Exception {
	// Run the WPE tool with three threads writing 3000 edits each concurrently.
	// When done, verify that all edits were written.
	int errCode = WALPerformanceEvaluation.
	innerMain(new Configuration(TEST_UTIL.getConfiguration()),
	new String [] {"-threads", "3", "-verify", "-noclosefs", "-iterations", "3000"});
	assertEquals(0, errCode);
	}

	/**
	* Ensure that we can use Set.add to deduplicate WALs
	*/
	@Test
	public void setMembershipDedups() throws IOException {
	Configuration localConf = new Configuration(conf);
	localConf.set(WALFactory.WAL_PROVIDER, FSHLogProvider.class.getName());
	WALFactory wals = new WALFactory(localConf, currentTest.getMethodName());
	try {
	final Set<WAL> seen = new HashSet<>(1);
	assertTrue("first attempt to add WAL from default provider should work.",
	seen.add(wals.getWAL(null)));
	for (int i = 0; i < 1000; i++) {
	assertFalse(
	"default wal provider is only supposed to return a single wal, which should " +
	"compare as .equals itself.",
	seen.add(wals.getWAL(RegionInfoBuilder
	.newBuilder(TableName.valueOf("Table-" + ThreadLocalRandom.current().nextInt()))
	.build())));
	}
	} finally {
	wals.close();
	}
	}
	}