hbase-server/src/main/java/org/apache/hadoop/hbase/regionserver/storefiletracker/StoreFileListFile.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.regionserver.storefiletracker;

 import com.google.errorprone.annotations.RestrictedApi;
 import java.io.EOFException;
 import java.io.FileNotFoundException;
 import java.io.IOException;
 import java.util.ArrayList;
 import java.util.Collections;
 import java.util.Comparator;
 import java.util.List;
 import java.util.Map;
 import java.util.NavigableMap;
 import java.util.TreeMap;
 import java.util.concurrent.ForkJoinPool;
 import java.util.regex.Pattern;
 import java.util.zip.CRC32;
 import org.apache.hadoop.fs.FSDataInputStream;
 import org.apache.hadoop.fs.FSDataOutputStream;
 import org.apache.hadoop.fs.FileStatus;
 import org.apache.hadoop.fs.FileSystem;
 import org.apache.hadoop.fs.Path;
 import org.apache.hadoop.hbase.DoNotRetryIOException;
 import org.apache.hadoop.hbase.regionserver.StoreContext;
 import org.apache.hadoop.hbase.util.EnvironmentEdgeManager;
 import org.apache.yetus.audience.InterfaceAudience;
 import org.slf4j.Logger;
 import org.slf4j.LoggerFactory;

 import org.apache.hbase.thirdparty.com.google.common.base.Splitter;

 import org.apache.hadoop.hbase.shaded.protobuf.generated.StoreFileTrackerProtos.StoreFileList;

 /**
  * To fully avoid listing, here we use two files for tracking. When loading, we will try to read
  * both the two files, if only one exists, we will trust this one, if both exist, we will compare
  * the timestamp to see which one is newer and trust that one. And we will record in memory that
  * which one is trusted by us, and when we need to update the store file list, we will write to the
  * other file.
  * <p/>
  * So in this way, we could avoid listing when we want to load the store file list file.
  * <p/>
  * To prevent loading partial file, we use the first 4 bytes as file length, and also append a 4
  * bytes crc32 checksum at the end. This is because the protobuf message parser sometimes can return
  * without error on partial bytes if you stop at some special points, but the return message will
  * have incorrect field value. We should try our best to prevent this happens because loading an
  * incorrect store file list file usually leads to data loss.
  * <p/>
  * To prevent failing silently while downgrading, where we may miss some newly introduced fields in
  * {@link StoreFileList} which are necessary, we introduce a 'version' field in
  * {@link StoreFileList}. If we find out that we are reading a {@link StoreFileList} with higher
  * version, we will fail immediately and tell users that you need extra steps while downgrading, to
  * prevent potential data loss.
  */
 @InterfaceAudience.Private
 class StoreFileListFile {

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

   // the current version for StoreFileList
   static final long VERSION = 1;

   static final String TRACK_FILE_DIR = ".filelist";

   static final String TRACK_FILE_PREFIX = "f1";

   private static final String TRACK_FILE_ROTATE_PREFIX = "f2";

   static final char TRACK_FILE_SEPARATOR = '.';

   static final Pattern TRACK_FILE_PATTERN = Pattern.compile("^f(1|2)\\.\\d+$");

   // 16 MB, which is big enough for a tracker file
   private static final int MAX_FILE_SIZE = 16 * 1024 * 1024;

   private final StoreContext ctx;

   private final Path trackFileDir;

   private final Path[] trackFiles = new Path[2];

   // this is used to make sure that we do not go backwards
   private long prevTimestamp = -1;

   private int nextTrackFile = -1;

   StoreFileListFile(StoreContext ctx) {
     this.ctx = ctx;
     trackFileDir = new Path(ctx.getFamilyStoreDirectoryPath(), TRACK_FILE_DIR);
   }

   static StoreFileList load(FileSystem fs, Path path) throws IOException {
     byte[] data;
     int expectedChecksum;
     try (FSDataInputStream in = fs.open(path)) {
       int length = in.readInt();
       if (length <= 0 || length > MAX_FILE_SIZE) {
         throw new IOException("Invalid file length " + length
           + ", either less than 0 or greater then max allowed size " + MAX_FILE_SIZE);
       }
       data = new byte[length];
       in.readFully(data);
       expectedChecksum = in.readInt();
     }
     CRC32 crc32 = new CRC32();
     crc32.update(data);
     int calculatedChecksum = (int) crc32.getValue();
     if (expectedChecksum != calculatedChecksum) {
       throw new IOException(
         "Checksum mismatch, expected " + expectedChecksum + ", actual " + calculatedChecksum);
     }
     StoreFileList storeFileList = StoreFileList.parseFrom(data);
     if (storeFileList.getVersion() > VERSION) {
       LOG.error(
         "The loaded store file list is in version {}, which is higher than expected"
           + " version {}. Stop loading to prevent potential data loss. This usually because your"
           + " cluster is downgraded from a newer version. You need extra steps before downgrading,"
           + " like switching back to default store file tracker.",
         storeFileList.getVersion(), VERSION);
       throw new IOException("Higher store file list version detected, expected " + VERSION
         + ", got " + storeFileList.getVersion());
     }
     return storeFileList;
   }

   StoreFileList load(Path path) throws IOException {
     FileSystem fs = ctx.getRegionFileSystem().getFileSystem();
     return load(fs, path);
   }

   private int select(StoreFileList[] lists) {
     if (lists[0] == null) {
       return 1;
     }
     if (lists[1] == null) {
       return 0;
     }
     return lists[0].getTimestamp() >= lists[1].getTimestamp() ? 0 : 1;
   }

   // file sequence id to path
   private NavigableMap<Long, List<Path>> listFiles() throws IOException {
     FileSystem fs = ctx.getRegionFileSystem().getFileSystem();
     FileStatus[] statuses;
     try {
       statuses = fs.listStatus(trackFileDir);
     } catch (FileNotFoundException e) {
       LOG.debug("Track file directory {} does not exist", trackFileDir, e);
       return Collections.emptyNavigableMap();
     }
     if (statuses == null || statuses.length == 0) {
       return Collections.emptyNavigableMap();
     }
     TreeMap<Long, List<Path>> map = new TreeMap<>(Comparator.reverseOrder());
     for (FileStatus status : statuses) {
       Path file = status.getPath();
       if (!status.isFile()) {
         LOG.warn("Found invalid track file {}, which is not a file", file);
         continue;
       }
       if (!TRACK_FILE_PATTERN.matcher(file.getName()).matches()) {
         LOG.warn("Found invalid track file {}, skip", file);
         continue;
       }
       List<String> parts = Splitter.on(TRACK_FILE_SEPARATOR).splitToList(file.getName());
       map.computeIfAbsent(Long.parseLong(parts.get(1)), k -> new ArrayList<>()).add(file);
     }
     return map;
   }

   private void initializeTrackFiles(long seqId) {
     trackFiles[0] = new Path(trackFileDir, TRACK_FILE_PREFIX + TRACK_FILE_SEPARATOR + seqId);
     trackFiles[1] = new Path(trackFileDir, TRACK_FILE_ROTATE_PREFIX + TRACK_FILE_SEPARATOR + seqId);
     LOG.info("Initialized track files: {}, {}", trackFiles[0], trackFiles[1]);
   }

   private void cleanUpTrackFiles(long loadedSeqId,
     NavigableMap<Long, List<Path>> seqId2TrackFiles) {
     LOG.info("Cleanup track file with sequence id < {}", loadedSeqId);
     FileSystem fs = ctx.getRegionFileSystem().getFileSystem();
     NavigableMap<Long, List<Path>> toDelete =
       loadedSeqId >= 0 ? seqId2TrackFiles.tailMap(loadedSeqId, false) : seqId2TrackFiles;
     toDelete.values().stream().flatMap(l -> l.stream()).forEach(file -> {
       ForkJoinPool.commonPool().execute(() -> {
         LOG.info("Deleting track file {}", file);
         try {
           fs.delete(file, false);
         } catch (IOException e) {
           LOG.warn("failed to delete unused track file {}", file, e);
         }
       });
     });
   }

   StoreFileList load(boolean readOnly) throws IOException {
     NavigableMap<Long, List<Path>> seqId2TrackFiles = listFiles();
     long seqId = -1L;
     StoreFileList[] lists = new StoreFileList[2];
     for (Map.Entry<Long, List<Path>> entry : seqId2TrackFiles.entrySet()) {
       List<Path> files = entry.getValue();
       // should not have more than 2 files, if not, it means that the track files are broken, just
       // throw exception out and fail the region open.
       if (files.size() > 2) {
         throw new DoNotRetryIOException("Should only have at most 2 track files for sequence id "
           + entry.getKey() + ", but got " + files.size() + " files: " + files);
       }
       boolean loaded = false;
       for (int i = 0; i < files.size(); i++) {
         try {
           lists[i] = load(files.get(i));
           loaded = true;
         } catch (EOFException e) {
           // this is normal case, so just log at debug
           LOG.debug("EOF loading track file {}, ignoring the exception", trackFiles[i], e);
         }
       }
       if (loaded) {
         seqId = entry.getKey();
         break;
       }
     }
     if (readOnly) {
       return lists[select(lists)];
     }

     cleanUpTrackFiles(seqId, seqId2TrackFiles);

     if (seqId < 0) {
       initializeTrackFiles(System.currentTimeMillis());
       nextTrackFile = 0;
       return null;
     }

     initializeTrackFiles(Math.max(System.currentTimeMillis(), seqId + 1));
     int winnerIndex = select(lists);
     nextTrackFile = 1 - winnerIndex;
     prevTimestamp = lists[winnerIndex].getTimestamp();
     return lists[winnerIndex];
   }

   @RestrictedApi(explanation = "Should only be called in tests", link = "",
       allowedOnPath = ".*/StoreFileListFile.java|.*/src/test/.*")
   static void write(FileSystem fs, Path file, StoreFileList storeFileList) throws IOException {
     byte[] data = storeFileList.toByteArray();
     CRC32 crc32 = new CRC32();
     crc32.update(data);
     int checksum = (int) crc32.getValue();
     // 4 bytes length at the beginning, plus 4 bytes checksum
     try (FSDataOutputStream out = fs.create(file, true)) {
       out.writeInt(data.length);
       out.write(data);
       out.writeInt(checksum);
     }
   }

   /**
    * We will set the timestamp and version in this method so just pass the builder in
    */
   void update(StoreFileList.Builder builder) throws IOException {
     if (nextTrackFile < 0) {
       // we need to call load first to load the prevTimestamp and also the next file
       // we are already in the update method, which is not read only, so pass false
       load(false);
     }
     FileSystem fs = ctx.getRegionFileSystem().getFileSystem();
     long timestamp = Math.max(prevTimestamp + 1, EnvironmentEdgeManager.currentTime());
     write(fs, trackFiles[nextTrackFile],
       builder.setTimestamp(timestamp).setVersion(VERSION).build());
     // record timestamp
     prevTimestamp = timestamp;
     // rotate the file
     nextTrackFile = 1 - nextTrackFile;

     try {
       fs.delete(trackFiles[nextTrackFile], false);
     } catch (IOException e) {
       // we will create new file with overwrite = true, so not a big deal here, only for speed up
       // loading as we do not need to read this file when loading
       LOG.debug("Failed to delete old track file {}, ignoring the exception",
         trackFiles[nextTrackFile], e);
     }
   }
 }
	/*
	* 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.regionserver.storefiletracker;

	import com.google.errorprone.annotations.RestrictedApi;
	import java.io.EOFException;
	import java.io.FileNotFoundException;
	import java.io.IOException;
	import java.util.ArrayList;
	import java.util.Collections;
	import java.util.Comparator;
	import java.util.List;
	import java.util.Map;
	import java.util.NavigableMap;
	import java.util.TreeMap;
	import java.util.concurrent.ForkJoinPool;
	import java.util.regex.Pattern;
	import java.util.zip.CRC32;
	import org.apache.hadoop.fs.FSDataInputStream;
	import org.apache.hadoop.fs.FSDataOutputStream;
	import org.apache.hadoop.fs.FileStatus;
	import org.apache.hadoop.fs.FileSystem;
	import org.apache.hadoop.fs.Path;
	import org.apache.hadoop.hbase.DoNotRetryIOException;
	import org.apache.hadoop.hbase.regionserver.StoreContext;
	import org.apache.hadoop.hbase.util.EnvironmentEdgeManager;
	import org.apache.yetus.audience.InterfaceAudience;
	import org.slf4j.Logger;
	import org.slf4j.LoggerFactory;

	import org.apache.hbase.thirdparty.com.google.common.base.Splitter;

	import org.apache.hadoop.hbase.shaded.protobuf.generated.StoreFileTrackerProtos.StoreFileList;

	/**
	* To fully avoid listing, here we use two files for tracking. When loading, we will try to read
	* both the two files, if only one exists, we will trust this one, if both exist, we will compare
	* the timestamp to see which one is newer and trust that one. And we will record in memory that
	* which one is trusted by us, and when we need to update the store file list, we will write to the
	* other file.
	* <p/>
	* So in this way, we could avoid listing when we want to load the store file list file.
	* <p/>
	* To prevent loading partial file, we use the first 4 bytes as file length, and also append a 4
	* bytes crc32 checksum at the end. This is because the protobuf message parser sometimes can return
	* without error on partial bytes if you stop at some special points, but the return message will
	* have incorrect field value. We should try our best to prevent this happens because loading an
	* incorrect store file list file usually leads to data loss.
	* <p/>
	* To prevent failing silently while downgrading, where we may miss some newly introduced fields in
	* {@link StoreFileList} which are necessary, we introduce a 'version' field in
	* {@link StoreFileList}. If we find out that we are reading a {@link StoreFileList} with higher
	* version, we will fail immediately and tell users that you need extra steps while downgrading, to
	* prevent potential data loss.
	*/
	@InterfaceAudience.Private
	class StoreFileListFile {

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

	// the current version for StoreFileList
	static final long VERSION = 1;

	static final String TRACK_FILE_DIR = ".filelist";

	static final String TRACK_FILE_PREFIX = "f1";

	private static final String TRACK_FILE_ROTATE_PREFIX = "f2";

	static final char TRACK_FILE_SEPARATOR = '.';

	static final Pattern TRACK_FILE_PATTERN = Pattern.compile("^f(1\|2)\\.\\d+$");

	// 16 MB, which is big enough for a tracker file
	private static final int MAX_FILE_SIZE = 16 * 1024 * 1024;

	private final StoreContext ctx;

	private final Path trackFileDir;

	private final Path[] trackFiles = new Path[2];

	// this is used to make sure that we do not go backwards
	private long prevTimestamp = -1;

	private int nextTrackFile = -1;

	StoreFileListFile(StoreContext ctx) {
	this.ctx = ctx;
	trackFileDir = new Path(ctx.getFamilyStoreDirectoryPath(), TRACK_FILE_DIR);
	}

	static StoreFileList load(FileSystem fs, Path path) throws IOException {
	byte[] data;
	int expectedChecksum;
	try (FSDataInputStream in = fs.open(path)) {
	int length = in.readInt();
	if (length <= 0 \|\| length > MAX_FILE_SIZE) {
	throw new IOException("Invalid file length " + length
	+ ", either less than 0 or greater then max allowed size " + MAX_FILE_SIZE);
	}
	data = new byte[length];
	in.readFully(data);
	expectedChecksum = in.readInt();
	}
	CRC32 crc32 = new CRC32();
	crc32.update(data);
	int calculatedChecksum = (int) crc32.getValue();
	if (expectedChecksum != calculatedChecksum) {
	throw new IOException(
	"Checksum mismatch, expected " + expectedChecksum + ", actual " + calculatedChecksum);
	}
	StoreFileList storeFileList = StoreFileList.parseFrom(data);
	if (storeFileList.getVersion() > VERSION) {
	LOG.error(
	"The loaded store file list is in version {}, which is higher than expected"
	+ " version {}. Stop loading to prevent potential data loss. This usually because your"
	+ " cluster is downgraded from a newer version. You need extra steps before downgrading,"
	+ " like switching back to default store file tracker.",
	storeFileList.getVersion(), VERSION);
	throw new IOException("Higher store file list version detected, expected " + VERSION
	+ ", got " + storeFileList.getVersion());
	}
	return storeFileList;
	}

	StoreFileList load(Path path) throws IOException {
	FileSystem fs = ctx.getRegionFileSystem().getFileSystem();
	return load(fs, path);
	}

	private int select(StoreFileList[] lists) {
	if (lists[0] == null) {
	return 1;
	}
	if (lists[1] == null) {
	return 0;
	}
	return lists[0].getTimestamp() >= lists[1].getTimestamp() ? 0 : 1;
	}

	// file sequence id to path
	private NavigableMap<Long, List<Path>> listFiles() throws IOException {
	FileSystem fs = ctx.getRegionFileSystem().getFileSystem();
	FileStatus[] statuses;
	try {
	statuses = fs.listStatus(trackFileDir);
	} catch (FileNotFoundException e) {
	LOG.debug("Track file directory {} does not exist", trackFileDir, e);
	return Collections.emptyNavigableMap();
	}
	if (statuses == null \|\| statuses.length == 0) {
	return Collections.emptyNavigableMap();
	}
	TreeMap<Long, List<Path>> map = new TreeMap<>(Comparator.reverseOrder());
	for (FileStatus status : statuses) {
	Path file = status.getPath();
	if (!status.isFile()) {
	LOG.warn("Found invalid track file {}, which is not a file", file);
	continue;
	}
	if (!TRACK_FILE_PATTERN.matcher(file.getName()).matches()) {
	LOG.warn("Found invalid track file {}, skip", file);
	continue;
	}
	List<String> parts = Splitter.on(TRACK_FILE_SEPARATOR).splitToList(file.getName());
	map.computeIfAbsent(Long.parseLong(parts.get(1)), k -> new ArrayList<>()).add(file);
	}
	return map;
	}

	private void initializeTrackFiles(long seqId) {
	trackFiles[0] = new Path(trackFileDir, TRACK_FILE_PREFIX + TRACK_FILE_SEPARATOR + seqId);
	trackFiles[1] = new Path(trackFileDir, TRACK_FILE_ROTATE_PREFIX + TRACK_FILE_SEPARATOR + seqId);
	LOG.info("Initialized track files: {}, {}", trackFiles[0], trackFiles[1]);
	}

	private void cleanUpTrackFiles(long loadedSeqId,
	NavigableMap<Long, List<Path>> seqId2TrackFiles) {
	LOG.info("Cleanup track file with sequence id < {}", loadedSeqId);
	FileSystem fs = ctx.getRegionFileSystem().getFileSystem();
	NavigableMap<Long, List<Path>> toDelete =
	loadedSeqId >= 0 ? seqId2TrackFiles.tailMap(loadedSeqId, false) : seqId2TrackFiles;
	toDelete.values().stream().flatMap(l -> l.stream()).forEach(file -> {
	ForkJoinPool.commonPool().execute(() -> {
	LOG.info("Deleting track file {}", file);
	try {
	fs.delete(file, false);
	} catch (IOException e) {
	LOG.warn("failed to delete unused track file {}", file, e);
	}
	});
	});
	}

	StoreFileList load(boolean readOnly) throws IOException {
	NavigableMap<Long, List<Path>> seqId2TrackFiles = listFiles();
	long seqId = -1L;
	StoreFileList[] lists = new StoreFileList[2];
	for (Map.Entry<Long, List<Path>> entry : seqId2TrackFiles.entrySet()) {
	List<Path> files = entry.getValue();
	// should not have more than 2 files, if not, it means that the track files are broken, just
	// throw exception out and fail the region open.
	if (files.size() > 2) {
	throw new DoNotRetryIOException("Should only have at most 2 track files for sequence id "
	+ entry.getKey() + ", but got " + files.size() + " files: " + files);
	}
	boolean loaded = false;
	for (int i = 0; i < files.size(); i++) {
	try {
	lists[i] = load(files.get(i));
	loaded = true;
	} catch (EOFException e) {
	// this is normal case, so just log at debug
	LOG.debug("EOF loading track file {}, ignoring the exception", trackFiles[i], e);
	}
	}
	if (loaded) {
	seqId = entry.getKey();
	break;
	}
	}
	if (readOnly) {
	return lists[select(lists)];
	}

	cleanUpTrackFiles(seqId, seqId2TrackFiles);

	if (seqId < 0) {
	initializeTrackFiles(System.currentTimeMillis());
	nextTrackFile = 0;
	return null;
	}

	initializeTrackFiles(Math.max(System.currentTimeMillis(), seqId + 1));
	int winnerIndex = select(lists);
	nextTrackFile = 1 - winnerIndex;
	prevTimestamp = lists[winnerIndex].getTimestamp();
	return lists[winnerIndex];
	}

	@RestrictedApi(explanation = "Should only be called in tests", link = "",
	allowedOnPath = "./StoreFileListFile.java\|./src/test/.*")
	static void write(FileSystem fs, Path file, StoreFileList storeFileList) throws IOException {
	byte[] data = storeFileList.toByteArray();
	CRC32 crc32 = new CRC32();
	crc32.update(data);
	int checksum = (int) crc32.getValue();
	// 4 bytes length at the beginning, plus 4 bytes checksum
	try (FSDataOutputStream out = fs.create(file, true)) {
	out.writeInt(data.length);
	out.write(data);
	out.writeInt(checksum);
	}
	}

	/**
	* We will set the timestamp and version in this method so just pass the builder in
	*/
	void update(StoreFileList.Builder builder) throws IOException {
	if (nextTrackFile < 0) {
	// we need to call load first to load the prevTimestamp and also the next file
	// we are already in the update method, which is not read only, so pass false
	load(false);
	}
	FileSystem fs = ctx.getRegionFileSystem().getFileSystem();
	long timestamp = Math.max(prevTimestamp + 1, EnvironmentEdgeManager.currentTime());
	write(fs, trackFiles[nextTrackFile],
	builder.setTimestamp(timestamp).setVersion(VERSION).build());
	// record timestamp
	prevTimestamp = timestamp;
	// rotate the file
	nextTrackFile = 1 - nextTrackFile;

	try {
	fs.delete(trackFiles[nextTrackFile], false);
	} catch (IOException e) {
	// we will create new file with overwrite = true, so not a big deal here, only for speed up
	// loading as we do not need to read this file when loading
	LOG.debug("Failed to delete old track file {}, ignoring the exception",
	trackFiles[nextTrackFile], e);
	}
	}
	}