hbase-server/src/main/java/org/apache/hadoop/hbase/wal/LogRecoveredEditsOutputSink.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.apache.hadoop.hbase.wal.WALSplitUtil.getCompletedRecoveredEditsFilePath;
 import static org.apache.hadoop.hbase.wal.WALSplitUtil.getRegionSplitEditsPath;

 import java.io.EOFException;
 import java.io.IOException;
 import java.io.InterruptedIOException;
 import java.util.ArrayList;
 import java.util.List;
 import java.util.Map;
 import java.util.TreeMap;
 import java.util.concurrent.Callable;
 import java.util.concurrent.CompletionService;
 import java.util.concurrent.ExecutionException;
 import java.util.concurrent.ExecutorCompletionService;
 import java.util.concurrent.Future;
 import java.util.concurrent.ThreadFactory;
 import java.util.concurrent.ThreadPoolExecutor;
 import java.util.concurrent.TimeUnit;

 import org.apache.hadoop.conf.Configuration;
 import org.apache.hadoop.fs.FileSystem;
 import org.apache.hadoop.fs.Path;
 import org.apache.hadoop.hbase.Cell;
 import org.apache.hadoop.hbase.CellUtil;
 import org.apache.hadoop.hbase.HConstants;
 import org.apache.hadoop.hbase.log.HBaseMarkers;
 import org.apache.hadoop.hbase.util.Bytes;
 import org.apache.hadoop.hbase.util.FSUtils;
 import org.apache.hadoop.hbase.util.Threads;
 import org.apache.hadoop.io.MultipleIOException;
 import org.apache.hadoop.ipc.RemoteException;
 import org.apache.yetus.audience.InterfaceAudience;
 import org.slf4j.Logger;
 import org.slf4j.LoggerFactory;

 import org.apache.hbase.thirdparty.com.google.common.base.Preconditions;
 import org.apache.hbase.thirdparty.com.google.common.collect.Lists;
 import org.apache.hbase.thirdparty.org.apache.commons.collections4.CollectionUtils;
 import org.apache.hbase.thirdparty.org.apache.commons.collections4.MapUtils;

 /**
  * Class that manages the output streams from the log splitting process.
  */
 @InterfaceAudience.Private
 public class LogRecoveredEditsOutputSink extends OutputSink {
   private static final Logger LOG = LoggerFactory.getLogger(LogRecoveredEditsOutputSink.class);
   private WALSplitter walSplitter;
   private FileSystem walFS;
   private Configuration conf;

   public LogRecoveredEditsOutputSink(WALSplitter walSplitter,
       WALSplitter.PipelineController controller, EntryBuffers entryBuffers, int numWriters) {
     // More threads could potentially write faster at the expense
     // of causing more disk seeks as the logs are split.
     // 3. After a certain setting (probably around 3) the
     // process will be bound on the reader in the current
     // implementation anyway.
     super(controller, entryBuffers, numWriters);
     this.walSplitter = walSplitter;
     this.walFS = walSplitter.walFS;
     this.conf = walSplitter.conf;
   }

   /**
    * @return null if failed to report progress
    */
   @Override
   public List<Path> finishWritingAndClose() throws IOException {
     boolean isSuccessful = false;
     List<Path> result = null;
     try {
       isSuccessful = finishWriting(false);
     } finally {
       result = close();
       List<IOException> thrown = closeLogWriters(null);
       if (CollectionUtils.isNotEmpty(thrown)) {
         throw MultipleIOException.createIOException(thrown);
       }
     }
     if (isSuccessful) {
       splits = result;
     }
     return splits;
   }

   // delete the one with fewer wal entries
   private void deleteOneWithFewerEntries(WALSplitter.WriterAndPath wap, Path dst)
       throws IOException {
     long dstMinLogSeqNum = -1L;
     try (WAL.Reader reader = walSplitter.getWalFactory().createReader(walSplitter.walFS, dst)) {
       WAL.Entry entry = reader.next();
       if (entry != null) {
         dstMinLogSeqNum = entry.getKey().getSequenceId();
       }
     } catch (EOFException e) {
       LOG.debug("Got EOF when reading first WAL entry from {}, an empty or broken WAL file?", dst,
         e);
     }
     if (wap.minLogSeqNum < dstMinLogSeqNum) {
       LOG.warn("Found existing old edits file. It could be the result of a previous failed"
           + " split attempt or we have duplicated wal entries. Deleting " + dst + ", length="
           + walFS.getFileStatus(dst).getLen());
       if (!walFS.delete(dst, false)) {
         LOG.warn("Failed deleting of old {}", dst);
         throw new IOException("Failed deleting of old " + dst);
       }
     } else {
       LOG.warn("Found existing old edits file and we have less entries. Deleting " + wap.path
           + ", length=" + walFS.getFileStatus(wap.path).getLen());
       if (!walFS.delete(wap.path, false)) {
         LOG.warn("Failed deleting of {}", wap.path);
         throw new IOException("Failed deleting of " + wap.path);
       }
     }
   }

   /**
    * Close all of the output streams.
    * @return the list of paths written.
    */
   List<Path> close() throws IOException {
     Preconditions.checkState(!closeAndCleanCompleted);

     final List<Path> paths = new ArrayList<>();
     final List<IOException> thrown = Lists.newArrayList();
     ThreadPoolExecutor closeThreadPool =
         Threads.getBoundedCachedThreadPool(numThreads, 30L, TimeUnit.SECONDS, new ThreadFactory() {
           private int count = 1;

           @Override
           public Thread newThread(Runnable r) {
             Thread t = new Thread(r, "split-log-closeStream-" + count++);
             return t;
           }
         });
     CompletionService<Void> completionService = new ExecutorCompletionService<>(closeThreadPool);
     boolean progress_failed;
     try {
       progress_failed = executeCloseTask(completionService, thrown, paths);
     } catch (InterruptedException e) {
       IOException iie = new InterruptedIOException();
       iie.initCause(e);
       throw iie;
     } catch (ExecutionException e) {
       throw new IOException(e.getCause());
     } finally {
       closeThreadPool.shutdownNow();
     }
     if (!thrown.isEmpty()) {
       throw MultipleIOException.createIOException(thrown);
     }
     writersClosed = true;
     closeAndCleanCompleted = true;
     if (progress_failed) {
       return null;
     }
     return paths;
   }

   /**
    * @param completionService threadPool to execute the closing tasks
    * @param thrown store the exceptions
    * @param paths arrayList to store the paths written
    * @return if close tasks executed successful
    */
   boolean executeCloseTask(CompletionService<Void> completionService, List<IOException> thrown,
       List<Path> paths) throws InterruptedException, ExecutionException {
     for (final Map.Entry<String, WALSplitter.SinkWriter> writersEntry : writers.entrySet()) {
       if (LOG.isTraceEnabled()) {
         LOG.trace(
           "Submitting close of " + ((WALSplitter.WriterAndPath) writersEntry.getValue()).path);
       }
       completionService.submit(new Callable<Void>() {
         @Override
         public Void call() throws Exception {
           WALSplitter.WriterAndPath wap = (WALSplitter.WriterAndPath) writersEntry.getValue();
           Path dst = closeWriter(writersEntry.getKey(), wap, thrown);
           paths.add(dst);
           return null;
         }
       });
     }
     boolean progress_failed = false;
     for (int i = 0, n = this.writers.size(); i < n; i++) {
       Future<Void> future = completionService.take();
       future.get();
       if (!progress_failed && reporter != null && !reporter.progress()) {
         progress_failed = true;
       }
     }
     return progress_failed;
   }

   Path closeWriter(String encodedRegionName, WALSplitter.WriterAndPath wap,
       List<IOException> thrown) throws IOException {
     LOG.trace("Closing {}", wap.path);
     try {
       wap.writer.close();
     } catch (IOException ioe) {
       LOG.error("Could not close log at {}", wap.path, ioe);
       thrown.add(ioe);
       return null;
     }
     if (LOG.isDebugEnabled()) {
       LOG.debug("Closed wap " + wap.path + " (wrote " + wap.editsWritten + " edits, skipped "
           + wap.editsSkipped + " edits in " + (wap.nanosSpent / 1000 / 1000) + "ms");
     }
     if (wap.editsWritten == 0) {
       // just remove the empty recovered.edits file
       if (walFS.exists(wap.path) && !walFS.delete(wap.path, false)) {
         LOG.warn("Failed deleting empty {}", wap.path);
         throw new IOException("Failed deleting empty  " + wap.path);
       }
       return null;
     }

     Path dst = getCompletedRecoveredEditsFilePath(wap.path,
       regionMaximumEditLogSeqNum.get(encodedRegionName));
     try {
       if (!dst.equals(wap.path) && walFS.exists(dst)) {
         deleteOneWithFewerEntries(wap, dst);
       }
       // Skip the unit tests which create a splitter that reads and
       // writes the data without touching disk.
       // TestHLogSplit#testThreading is an example.
       if (walFS.exists(wap.path)) {
         if (!walFS.rename(wap.path, dst)) {
           throw new IOException("Failed renaming " + wap.path + " to " + dst);
         }
         LOG.info("Rename {} to {}", wap.path, dst);
       }
     } catch (IOException ioe) {
       LOG.error("Could not rename {} to {}", wap.path, dst, ioe);
       thrown.add(ioe);
       return null;
     }
     return dst;
   }

   private List<IOException> closeLogWriters(List<IOException> thrown) throws IOException {
     if (writersClosed) {
       return thrown;
     }
     if (thrown == null) {
       thrown = Lists.newArrayList();
     }
     try {
       for (WriterThread writerThread : writerThreads) {
         while (writerThread.isAlive()) {
           writerThread.setShouldStop(true);
           writerThread.interrupt();
           try {
             writerThread.join(10);
           } catch (InterruptedException e) {
             IOException iie = new InterruptedIOException();
             iie.initCause(e);
             throw iie;
           }
         }
       }
     } finally {
       WALSplitter.WriterAndPath wap = null;
       for (WALSplitter.SinkWriter tmpWAP : writers.values()) {
         try {
           wap = (WALSplitter.WriterAndPath) tmpWAP;
           wap.writer.close();
         } catch (IOException ioe) {
           LOG.error("Couldn't close log at {}", wap.path, ioe);
           thrown.add(ioe);
           continue;
         }
         LOG.info("Closed log " + wap.path + " (wrote " + wap.editsWritten + " edits in "
             + (wap.nanosSpent / 1000 / 1000) + "ms)");
       }
       writersClosed = true;
     }

     return thrown;
   }

   /**
    * Get a writer and path for a log starting at the given entry. This function is threadsafe so
    * long as multiple threads are always acting on different regions.
    * @return null if this region shouldn't output any logs
    */
   WALSplitter.WriterAndPath getWriterAndPath(WAL.Entry entry, boolean reusable) throws IOException {
     byte[] region = entry.getKey().getEncodedRegionName();
     String regionName = Bytes.toString(region);
     WALSplitter.WriterAndPath ret = (WALSplitter.WriterAndPath) writers.get(regionName);
     if (ret != null) {
       return ret;
     }
     // If we already decided that this region doesn't get any output
     // we don't need to check again.
     if (blacklistedRegions.contains(region)) {
       return null;
     }
     ret = createWAP(region, entry);
     if (ret == null) {
       blacklistedRegions.add(region);
       return null;
     }
     if (reusable) {
       writers.put(regionName, ret);
     }
     return ret;
   }

   /**
    * @return a path with a write for that path. caller should close.
    */
   WALSplitter.WriterAndPath createWAP(byte[] region, WAL.Entry entry) throws IOException {
     String tmpDirName = walSplitter.conf.get(HConstants.TEMPORARY_FS_DIRECTORY_KEY,
       HConstants.DEFAULT_TEMPORARY_HDFS_DIRECTORY);
     Path regionedits = getRegionSplitEditsPath(entry,
       walSplitter.getFileBeingSplit().getPath().getName(), tmpDirName, conf);
     if (regionedits == null) {
       return null;
     }
     FileSystem walFs = FSUtils.getWALFileSystem(conf);
     if (walFs.exists(regionedits)) {
       LOG.warn("Found old edits file. It could be the "
           + "result of a previous failed split attempt. Deleting " + regionedits + ", length="
           + walFs.getFileStatus(regionedits).getLen());
       if (!walFs.delete(regionedits, false)) {
         LOG.warn("Failed delete of old {}", regionedits);
       }
     }
     WALProvider.Writer w = walSplitter.createWriter(regionedits);
     LOG.debug("Creating writer path={}", regionedits);
     return new WALSplitter.WriterAndPath(regionedits, w, entry.getKey().getSequenceId());
   }


   void filterCellByStore(WAL.Entry logEntry) {
     Map<byte[], Long> maxSeqIdInStores = walSplitter.getRegionMaxSeqIdInStores()
         .get(Bytes.toString(logEntry.getKey().getEncodedRegionName()));
     if (MapUtils.isEmpty(maxSeqIdInStores)) {
       return;
     }
     // Create the array list for the cells that aren't filtered.
     // We make the assumption that most cells will be kept.
     ArrayList<Cell> keptCells = new ArrayList<>(logEntry.getEdit().getCells().size());
     for (Cell cell : logEntry.getEdit().getCells()) {
       if (WALEdit.isMetaEditFamily(cell)) {
         keptCells.add(cell);
       } else {
         byte[] family = CellUtil.cloneFamily(cell);
         Long maxSeqId = maxSeqIdInStores.get(family);
         // Do not skip cell even if maxSeqId is null. Maybe we are in a rolling upgrade,
         // or the master was crashed before and we can not get the information.
         if (maxSeqId == null || maxSeqId.longValue() < logEntry.getKey().getSequenceId()) {
           keptCells.add(cell);
         }
       }
     }

     // Anything in the keptCells array list is still live.
     // So rather than removing the cells from the array list
     // which would be an O(n^2) operation, we just replace the list
     logEntry.getEdit().setCells(keptCells);
   }

   @Override
   public void append(WALSplitter.RegionEntryBuffer buffer) throws IOException {
     appendBuffer(buffer, true);
   }

   WALSplitter.WriterAndPath appendBuffer(WALSplitter.RegionEntryBuffer buffer, boolean reusable)
       throws IOException {
     List<WAL.Entry> entries = buffer.entryBuffer;
     if (entries.isEmpty()) {
       LOG.warn("got an empty buffer, skipping");
       return null;
     }

     WALSplitter.WriterAndPath wap = null;

     long startTime = System.nanoTime();
     try {
       int editsCount = 0;

       for (WAL.Entry logEntry : entries) {
         if (wap == null) {
           wap = getWriterAndPath(logEntry, reusable);
           if (wap == null) {
             // This log spews the full edit. Can be massive in the log. Enable only debugging
             // WAL lost edit issues.
             LOG.trace("getWriterAndPath decided we don't need to write edits for {}", logEntry);
             return null;
           }
         }
         filterCellByStore(logEntry);
         if (!logEntry.getEdit().isEmpty()) {
           wap.writer.append(logEntry);
           this.updateRegionMaximumEditLogSeqNum(logEntry);
           editsCount++;
         } else {
           wap.incrementSkippedEdits(1);
         }
       }
       // Pass along summary statistics
       wap.incrementEdits(editsCount);
       wap.incrementNanoTime(System.nanoTime() - startTime);
     } catch (IOException e) {
       e = e instanceof RemoteException ? ((RemoteException) e).unwrapRemoteException() : e;
       LOG.error(HBaseMarkers.FATAL, "Got while writing log entry to log", e);
       throw e;
     }
     return wap;
   }

   @Override
   public boolean keepRegionEvent(WAL.Entry entry) {
     ArrayList<Cell> cells = entry.getEdit().getCells();
     for (Cell cell : cells) {
       if (WALEdit.isCompactionMarker(cell)) {
         return true;
       }
     }
     return false;
   }

   /**
    * @return a map from encoded region ID to the number of edits written out for that region.
    */
   @Override
   public Map<byte[], Long> getOutputCounts() {
     TreeMap<byte[], Long> ret = new TreeMap<>(Bytes.BYTES_COMPARATOR);
     for (Map.Entry<String, WALSplitter.SinkWriter> entry : writers.entrySet()) {
       ret.put(Bytes.toBytes(entry.getKey()), entry.getValue().editsWritten);
     }
     return ret;
   }

   @Override
   public int getNumberOfRecoveredRegions() {
     return writers.size();
   }
 }
	/**
	* 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.apache.hadoop.hbase.wal.WALSplitUtil.getCompletedRecoveredEditsFilePath;
	import static org.apache.hadoop.hbase.wal.WALSplitUtil.getRegionSplitEditsPath;

	import java.io.EOFException;
	import java.io.IOException;
	import java.io.InterruptedIOException;
	import java.util.ArrayList;
	import java.util.List;
	import java.util.Map;
	import java.util.TreeMap;
	import java.util.concurrent.Callable;
	import java.util.concurrent.CompletionService;
	import java.util.concurrent.ExecutionException;
	import java.util.concurrent.ExecutorCompletionService;
	import java.util.concurrent.Future;
	import java.util.concurrent.ThreadFactory;
	import java.util.concurrent.ThreadPoolExecutor;
	import java.util.concurrent.TimeUnit;

	import org.apache.hadoop.conf.Configuration;
	import org.apache.hadoop.fs.FileSystem;
	import org.apache.hadoop.fs.Path;
	import org.apache.hadoop.hbase.Cell;
	import org.apache.hadoop.hbase.CellUtil;
	import org.apache.hadoop.hbase.HConstants;
	import org.apache.hadoop.hbase.log.HBaseMarkers;
	import org.apache.hadoop.hbase.util.Bytes;
	import org.apache.hadoop.hbase.util.FSUtils;
	import org.apache.hadoop.hbase.util.Threads;
	import org.apache.hadoop.io.MultipleIOException;
	import org.apache.hadoop.ipc.RemoteException;
	import org.apache.yetus.audience.InterfaceAudience;
	import org.slf4j.Logger;
	import org.slf4j.LoggerFactory;

	import org.apache.hbase.thirdparty.com.google.common.base.Preconditions;
	import org.apache.hbase.thirdparty.com.google.common.collect.Lists;
	import org.apache.hbase.thirdparty.org.apache.commons.collections4.CollectionUtils;
	import org.apache.hbase.thirdparty.org.apache.commons.collections4.MapUtils;

	/**
	* Class that manages the output streams from the log splitting process.
	*/
	@InterfaceAudience.Private
	public class LogRecoveredEditsOutputSink extends OutputSink {
	private static final Logger LOG = LoggerFactory.getLogger(LogRecoveredEditsOutputSink.class);
	private WALSplitter walSplitter;
	private FileSystem walFS;
	private Configuration conf;

	public LogRecoveredEditsOutputSink(WALSplitter walSplitter,
	WALSplitter.PipelineController controller, EntryBuffers entryBuffers, int numWriters) {
	// More threads could potentially write faster at the expense
	// of causing more disk seeks as the logs are split.
	// 3. After a certain setting (probably around 3) the
	// process will be bound on the reader in the current
	// implementation anyway.
	super(controller, entryBuffers, numWriters);
	this.walSplitter = walSplitter;
	this.walFS = walSplitter.walFS;
	this.conf = walSplitter.conf;
	}

	/**
	* @return null if failed to report progress
	*/
	@Override
	public List<Path> finishWritingAndClose() throws IOException {
	boolean isSuccessful = false;
	List<Path> result = null;
	try {
	isSuccessful = finishWriting(false);
	} finally {
	result = close();
	List<IOException> thrown = closeLogWriters(null);
	if (CollectionUtils.isNotEmpty(thrown)) {
	throw MultipleIOException.createIOException(thrown);
	}
	}
	if (isSuccessful) {
	splits = result;
	}
	return splits;
	}

	// delete the one with fewer wal entries
	private void deleteOneWithFewerEntries(WALSplitter.WriterAndPath wap, Path dst)
	throws IOException {
	long dstMinLogSeqNum = -1L;
	try (WAL.Reader reader = walSplitter.getWalFactory().createReader(walSplitter.walFS, dst)) {
	WAL.Entry entry = reader.next();
	if (entry != null) {
	dstMinLogSeqNum = entry.getKey().getSequenceId();
	}
	} catch (EOFException e) {
	LOG.debug("Got EOF when reading first WAL entry from {}, an empty or broken WAL file?", dst,
	e);
	}
	if (wap.minLogSeqNum < dstMinLogSeqNum) {
	LOG.warn("Found existing old edits file. It could be the result of a previous failed"
	+ " split attempt or we have duplicated wal entries. Deleting " + dst + ", length="
	+ walFS.getFileStatus(dst).getLen());
	if (!walFS.delete(dst, false)) {
	LOG.warn("Failed deleting of old {}", dst);
	throw new IOException("Failed deleting of old " + dst);
	}
	} else {
	LOG.warn("Found existing old edits file and we have less entries. Deleting " + wap.path
	+ ", length=" + walFS.getFileStatus(wap.path).getLen());
	if (!walFS.delete(wap.path, false)) {
	LOG.warn("Failed deleting of {}", wap.path);
	throw new IOException("Failed deleting of " + wap.path);
	}
	}
	}

	/**
	* Close all of the output streams.
	* @return the list of paths written.
	*/
	List<Path> close() throws IOException {
	Preconditions.checkState(!closeAndCleanCompleted);

	final List<Path> paths = new ArrayList<>();
	final List<IOException> thrown = Lists.newArrayList();
	ThreadPoolExecutor closeThreadPool =
	Threads.getBoundedCachedThreadPool(numThreads, 30L, TimeUnit.SECONDS, new ThreadFactory() {
	private int count = 1;

	@Override
	public Thread newThread(Runnable r) {
	Thread t = new Thread(r, "split-log-closeStream-" + count++);
	return t;
	}
	});
	CompletionService<Void> completionService = new ExecutorCompletionService<>(closeThreadPool);
	boolean progress_failed;
	try {
	progress_failed = executeCloseTask(completionService, thrown, paths);
	} catch (InterruptedException e) {
	IOException iie = new InterruptedIOException();
	iie.initCause(e);
	throw iie;
	} catch (ExecutionException e) {
	throw new IOException(e.getCause());
	} finally {
	closeThreadPool.shutdownNow();
	}
	if (!thrown.isEmpty()) {
	throw MultipleIOException.createIOException(thrown);
	}
	writersClosed = true;
	closeAndCleanCompleted = true;
	if (progress_failed) {
	return null;
	}
	return paths;
	}

	/**
	* @param completionService threadPool to execute the closing tasks
	* @param thrown store the exceptions
	* @param paths arrayList to store the paths written
	* @return if close tasks executed successful
	*/
	boolean executeCloseTask(CompletionService<Void> completionService, List<IOException> thrown,
	List<Path> paths) throws InterruptedException, ExecutionException {
	for (final Map.Entry<String, WALSplitter.SinkWriter> writersEntry : writers.entrySet()) {
	if (LOG.isTraceEnabled()) {
	LOG.trace(
	"Submitting close of " + ((WALSplitter.WriterAndPath) writersEntry.getValue()).path);
	}
	completionService.submit(new Callable<Void>() {
	@Override
	public Void call() throws Exception {
	WALSplitter.WriterAndPath wap = (WALSplitter.WriterAndPath) writersEntry.getValue();
	Path dst = closeWriter(writersEntry.getKey(), wap, thrown);
	paths.add(dst);
	return null;
	}
	});
	}
	boolean progress_failed = false;
	for (int i = 0, n = this.writers.size(); i < n; i++) {
	Future<Void> future = completionService.take();
	future.get();
	if (!progress_failed && reporter != null && !reporter.progress()) {
	progress_failed = true;
	}
	}
	return progress_failed;
	}

	Path closeWriter(String encodedRegionName, WALSplitter.WriterAndPath wap,
	List<IOException> thrown) throws IOException {
	LOG.trace("Closing {}", wap.path);
	try {
	wap.writer.close();
	} catch (IOException ioe) {
	LOG.error("Could not close log at {}", wap.path, ioe);
	thrown.add(ioe);
	return null;
	}
	if (LOG.isDebugEnabled()) {
	LOG.debug("Closed wap " + wap.path + " (wrote " + wap.editsWritten + " edits, skipped "
	+ wap.editsSkipped + " edits in " + (wap.nanosSpent / 1000 / 1000) + "ms");
	}
	if (wap.editsWritten == 0) {
	// just remove the empty recovered.edits file
	if (walFS.exists(wap.path) && !walFS.delete(wap.path, false)) {
	LOG.warn("Failed deleting empty {}", wap.path);
	throw new IOException("Failed deleting empty " + wap.path);
	}
	return null;
	}

	Path dst = getCompletedRecoveredEditsFilePath(wap.path,
	regionMaximumEditLogSeqNum.get(encodedRegionName));
	try {
	if (!dst.equals(wap.path) && walFS.exists(dst)) {
	deleteOneWithFewerEntries(wap, dst);
	}
	// Skip the unit tests which create a splitter that reads and
	// writes the data without touching disk.
	// TestHLogSplit#testThreading is an example.
	if (walFS.exists(wap.path)) {
	if (!walFS.rename(wap.path, dst)) {
	throw new IOException("Failed renaming " + wap.path + " to " + dst);
	}
	LOG.info("Rename {} to {}", wap.path, dst);
	}
	} catch (IOException ioe) {
	LOG.error("Could not rename {} to {}", wap.path, dst, ioe);
	thrown.add(ioe);
	return null;
	}
	return dst;
	}

	private List<IOException> closeLogWriters(List<IOException> thrown) throws IOException {
	if (writersClosed) {
	return thrown;
	}
	if (thrown == null) {
	thrown = Lists.newArrayList();
	}
	try {
	for (WriterThread writerThread : writerThreads) {
	while (writerThread.isAlive()) {
	writerThread.setShouldStop(true);
	writerThread.interrupt();
	try {
	writerThread.join(10);
	} catch (InterruptedException e) {
	IOException iie = new InterruptedIOException();
	iie.initCause(e);
	throw iie;
	}
	}
	}
	} finally {
	WALSplitter.WriterAndPath wap = null;
	for (WALSplitter.SinkWriter tmpWAP : writers.values()) {
	try {
	wap = (WALSplitter.WriterAndPath) tmpWAP;
	wap.writer.close();
	} catch (IOException ioe) {
	LOG.error("Couldn't close log at {}", wap.path, ioe);
	thrown.add(ioe);
	continue;
	}
	LOG.info("Closed log " + wap.path + " (wrote " + wap.editsWritten + " edits in "
	+ (wap.nanosSpent / 1000 / 1000) + "ms)");
	}
	writersClosed = true;
	}

	return thrown;
	}

	/**
	* Get a writer and path for a log starting at the given entry. This function is threadsafe so
	* long as multiple threads are always acting on different regions.
	* @return null if this region shouldn't output any logs
	*/
	WALSplitter.WriterAndPath getWriterAndPath(WAL.Entry entry, boolean reusable) throws IOException {
	byte[] region = entry.getKey().getEncodedRegionName();
	String regionName = Bytes.toString(region);
	WALSplitter.WriterAndPath ret = (WALSplitter.WriterAndPath) writers.get(regionName);
	if (ret != null) {
	return ret;
	}
	// If we already decided that this region doesn't get any output
	// we don't need to check again.
	if (blacklistedRegions.contains(region)) {
	return null;
	}
	ret = createWAP(region, entry);
	if (ret == null) {
	blacklistedRegions.add(region);
	return null;
	}
	if (reusable) {
	writers.put(regionName, ret);
	}
	return ret;
	}

	/**
	* @return a path with a write for that path. caller should close.
	*/
	WALSplitter.WriterAndPath createWAP(byte[] region, WAL.Entry entry) throws IOException {
	String tmpDirName = walSplitter.conf.get(HConstants.TEMPORARY_FS_DIRECTORY_KEY,
	HConstants.DEFAULT_TEMPORARY_HDFS_DIRECTORY);
	Path regionedits = getRegionSplitEditsPath(entry,
	walSplitter.getFileBeingSplit().getPath().getName(), tmpDirName, conf);
	if (regionedits == null) {
	return null;
	}
	FileSystem walFs = FSUtils.getWALFileSystem(conf);
	if (walFs.exists(regionedits)) {
	LOG.warn("Found old edits file. It could be the "
	+ "result of a previous failed split attempt. Deleting " + regionedits + ", length="
	+ walFs.getFileStatus(regionedits).getLen());
	if (!walFs.delete(regionedits, false)) {
	LOG.warn("Failed delete of old {}", regionedits);
	}
	}
	WALProvider.Writer w = walSplitter.createWriter(regionedits);
	LOG.debug("Creating writer path={}", regionedits);
	return new WALSplitter.WriterAndPath(regionedits, w, entry.getKey().getSequenceId());
	}



	void filterCellByStore(WAL.Entry logEntry) {
	Map<byte[], Long> maxSeqIdInStores = walSplitter.getRegionMaxSeqIdInStores()
	.get(Bytes.toString(logEntry.getKey().getEncodedRegionName()));
	if (MapUtils.isEmpty(maxSeqIdInStores)) {
	return;
	}
	// Create the array list for the cells that aren't filtered.
	// We make the assumption that most cells will be kept.
	ArrayList<Cell> keptCells = new ArrayList<>(logEntry.getEdit().getCells().size());
	for (Cell cell : logEntry.getEdit().getCells()) {
	if (WALEdit.isMetaEditFamily(cell)) {
	keptCells.add(cell);
	} else {
	byte[] family = CellUtil.cloneFamily(cell);
	Long maxSeqId = maxSeqIdInStores.get(family);
	// Do not skip cell even if maxSeqId is null. Maybe we are in a rolling upgrade,
	// or the master was crashed before and we can not get the information.
	if (maxSeqId == null \|\| maxSeqId.longValue() < logEntry.getKey().getSequenceId()) {
	keptCells.add(cell);
	}
	}
	}

	// Anything in the keptCells array list is still live.
	// So rather than removing the cells from the array list
	// which would be an O(n^2) operation, we just replace the list
	logEntry.getEdit().setCells(keptCells);
	}

	@Override
	public void append(WALSplitter.RegionEntryBuffer buffer) throws IOException {
	appendBuffer(buffer, true);
	}

	WALSplitter.WriterAndPath appendBuffer(WALSplitter.RegionEntryBuffer buffer, boolean reusable)
	throws IOException {
	List<WAL.Entry> entries = buffer.entryBuffer;
	if (entries.isEmpty()) {
	LOG.warn("got an empty buffer, skipping");
	return null;
	}

	WALSplitter.WriterAndPath wap = null;

	long startTime = System.nanoTime();
	try {
	int editsCount = 0;

	for (WAL.Entry logEntry : entries) {
	if (wap == null) {
	wap = getWriterAndPath(logEntry, reusable);
	if (wap == null) {
	// This log spews the full edit. Can be massive in the log. Enable only debugging
	// WAL lost edit issues.
	LOG.trace("getWriterAndPath decided we don't need to write edits for {}", logEntry);
	return null;
	}
	}
	filterCellByStore(logEntry);
	if (!logEntry.getEdit().isEmpty()) {
	wap.writer.append(logEntry);
	this.updateRegionMaximumEditLogSeqNum(logEntry);
	editsCount++;
	} else {
	wap.incrementSkippedEdits(1);
	}
	}
	// Pass along summary statistics
	wap.incrementEdits(editsCount);
	wap.incrementNanoTime(System.nanoTime() - startTime);
	} catch (IOException e) {
	e = e instanceof RemoteException ? ((RemoteException) e).unwrapRemoteException() : e;
	LOG.error(HBaseMarkers.FATAL, "Got while writing log entry to log", e);
	throw e;
	}
	return wap;
	}

	@Override
	public boolean keepRegionEvent(WAL.Entry entry) {
	ArrayList<Cell> cells = entry.getEdit().getCells();
	for (Cell cell : cells) {
	if (WALEdit.isCompactionMarker(cell)) {
	return true;
	}
	}
	return false;
	}

	/**
	* @return a map from encoded region ID to the number of edits written out for that region.
	*/
	@Override
	public Map<byte[], Long> getOutputCounts() {
	TreeMap<byte[], Long> ret = new TreeMap<>(Bytes.BYTES_COMPARATOR);
	for (Map.Entry<String, WALSplitter.SinkWriter> entry : writers.entrySet()) {
	ret.put(Bytes.toBytes(entry.getKey()), entry.getValue().editsWritten);
	}
	return ret;
	}

	@Override
	public int getNumberOfRecoveredRegions() {
	return writers.size();
	}
	}