org.apache.hadoop.hbase.wal.LogRecoveredEditsOutputSink.java Source code

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/**
 * 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 (CellUtil.matchingFamily(cell, WALEdit.METAFAMILY)) {
                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();
    }
}