/**
* 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.snapshot;
import java.io.FileNotFoundException;
import java.io.IOException;
import java.util.ArrayList;
import java.util.Collections;
import java.util.Comparator;
import java.util.LinkedList;
import java.util.List;
import org.apache.commons.logging.Log;
import org.apache.commons.logging.LogFactory;
import org.apache.hadoop.classification.InterfaceAudience;
import org.apache.hadoop.classification.InterfaceStability;
import org.apache.hadoop.conf.Configuration;
import org.apache.hadoop.conf.Configured;
import org.apache.hadoop.fs.FSDataInputStream;
import org.apache.hadoop.fs.FSDataOutputStream;
import org.apache.hadoop.fs.FileChecksum;
import org.apache.hadoop.fs.FileStatus;
import org.apache.hadoop.fs.FileSystem;
import org.apache.hadoop.fs.FileUtil;
import org.apache.hadoop.fs.Path;
import org.apache.hadoop.fs.permission.FsPermission;
import org.apache.hadoop.hbase.HBaseConfiguration;
import org.apache.hadoop.hbase.HConstants;
import org.apache.hadoop.hbase.io.HFileLink;
import org.apache.hadoop.hbase.io.HLogLink;
import org.apache.hadoop.hbase.protobuf.generated.HBaseProtos.SnapshotDescription;
import org.apache.hadoop.hbase.regionserver.StoreFile;
import org.apache.hadoop.hbase.snapshot.ExportSnapshotException;
import org.apache.hadoop.hbase.snapshot.SnapshotDescriptionUtils;
import org.apache.hadoop.hbase.snapshot.SnapshotReferenceUtil;
import org.apache.hadoop.hbase.util.Bytes;
import org.apache.hadoop.hbase.util.EnvironmentEdgeManager;
import org.apache.hadoop.hbase.util.FSUtils;
import org.apache.hadoop.hbase.util.Pair;
import org.apache.hadoop.io.NullWritable;
import org.apache.hadoop.io.SequenceFile;
import org.apache.hadoop.io.Text;
import org.apache.hadoop.mapreduce.Job;
import org.apache.hadoop.mapreduce.Mapper;
import org.apache.hadoop.mapreduce.lib.input.SequenceFileInputFormat;
import org.apache.hadoop.mapreduce.lib.input.TextInputFormat;
import org.apache.hadoop.mapreduce.lib.output.FileOutputFormat;
import org.apache.hadoop.mapreduce.lib.output.NullOutputFormat;
import org.apache.hadoop.util.StringUtils;
import org.apache.hadoop.util.Tool;
import org.apache.hadoop.util.ToolRunner;
/**
* Export the specified snapshot to a given FileSystem.
*
* The .snapshot/name folder is copied to the destination cluster
* and then all the hfiles/hlogs are copied using a Map-Reduce Job in the .archive/ location.
* When everything is done, the second cluster can restore the snapshot.
*/
@InterfaceAudience.Public
@InterfaceStability.Evolving
public final class ExportSnapshot extends Configured implements Tool {
private static final Log LOG = LogFactory.getLog(ExportSnapshot.class);
private static final String CONF_FILES_USER = "snapshot.export.files.attributes.user";
private static final String CONF_FILES_GROUP = "snapshot.export.files.attributes.group";
private static final String CONF_FILES_MODE = "snapshot.export.files.attributes.mode";
private static final String CONF_CHECKSUM_VERIFY = "snapshot.export.checksum.verify";
private static final String CONF_OUTPUT_ROOT = "snapshot.export.output.root";
private static final String CONF_INPUT_ROOT = "snapshot.export.input.root";
private static final String CONF_STAGING_ROOT = "snapshot.export.staging.root";
private static final String INPUT_FOLDER_PREFIX = "export-files.";
// Export Map-Reduce Counters, to keep track of the progress
public enum Counter { MISSING_FILES, COPY_FAILED, BYTES_EXPECTED, BYTES_COPIED };
private static class ExportMapper extends Mapper<Text, NullWritable, NullWritable, NullWritable> {
final static int REPORT_SIZE = 1 * 1024 * 1024;
final static int BUFFER_SIZE = 64 * 1024;
private boolean verifyChecksum;
private String filesGroup;
private String filesUser;
private short filesMode;
private FileSystem outputFs;
private Path outputArchive;
private Path outputRoot;
private FileSystem inputFs;
private Path inputArchive;
private Path inputRoot;
@Override
public void setup(Context context) {
Configuration conf = context.getConfiguration();
verifyChecksum = conf.getBoolean(CONF_CHECKSUM_VERIFY, true);
filesGroup = conf.get(CONF_FILES_GROUP);
filesUser = conf.get(CONF_FILES_USER);
filesMode = (short)conf.getInt(CONF_FILES_MODE, 0);
outputRoot = new Path(conf.get(CONF_OUTPUT_ROOT));
inputRoot = new Path(conf.get(CONF_INPUT_ROOT));
inputArchive = new Path(inputRoot, HConstants.HFILE_ARCHIVE_DIRECTORY);
outputArchive = new Path(outputRoot, HConstants.HFILE_ARCHIVE_DIRECTORY);
try {
inputFs = FileSystem.get(inputRoot.toUri(), conf);
} catch (IOException e) {
throw new RuntimeException("Could not get the input FileSystem with root=" + inputRoot, e);
}
try {
outputFs = FileSystem.get(outputRoot.toUri(), conf);
} catch (IOException e) {
throw new RuntimeException("Could not get the output FileSystem with root="+ outputRoot, e);
}
}
@Override
public void map(Text key, NullWritable value, Context context)
throws InterruptedException, IOException {
Path inputPath = new Path(key.toString());
Path outputPath = getOutputPath(inputPath);
LOG.info("copy file input=" + inputPath + " output=" + outputPath);
if (copyFile(context, inputPath, outputPath)) {
LOG.info("copy completed for input=" + inputPath + " output=" + outputPath);
}
}
/**
* Returns the location where the inputPath will be copied.
* - hfiles are encoded as hfile links hfile-region-table
* - logs are encoded as serverName/logName
*/
private Path getOutputPath(final Path inputPath) throws IOException {
Path path;
if (HFileLink.isHFileLink(inputPath) || StoreFile.isReference(inputPath)) {
String family = inputPath.getParent().getName();
String table = HFileLink.getReferencedTableName(inputPath.getName());
String region = HFileLink.getReferencedRegionName(inputPath.getName());
String hfile = HFileLink.getReferencedHFileName(inputPath.getName());
path = new Path(table, new Path(region, new Path(family, hfile)));
} else if (isHLogLinkPath(inputPath)) {
String logName = inputPath.getName();
path = new Path(new Path(outputRoot, HConstants.HREGION_OLDLOGDIR_NAME), logName);
} else {
path = inputPath;
}
return new Path(outputArchive, path);
}
private boolean copyFile(final Context context, final Path inputPath, final Path outputPath)
throws IOException {
FSDataInputStream in = openSourceFile(inputPath);
if (in == null) {
context.getCounter(Counter.MISSING_FILES).increment(1);
return false;
}
try {
// Verify if the input file exists
FileStatus inputStat = getFileStatus(inputFs, inputPath);
if (inputStat == null) return false;
// Verify if the output file exists and is the same that we want to copy
if (outputFs.exists(outputPath)) {
FileStatus outputStat = outputFs.getFileStatus(outputPath);
if (sameFile(inputStat, outputStat)) {
LOG.info("Skip copy " + inputPath + " to " + outputPath + ", same file.");
return true;
}
}
context.getCounter(Counter.BYTES_EXPECTED).increment(inputStat.getLen());
// Ensure that the output folder is there and copy the file
outputFs.mkdirs(outputPath.getParent());
FSDataOutputStream out = outputFs.create(outputPath, true);
try {
if (!copyData(context, inputPath, in, outputPath, out, inputStat.getLen()))
return false;
} finally {
out.close();
}
// Preserve attributes
return preserveAttributes(outputPath, inputStat);
} finally {
in.close();
}
}
/**
* Preserve the files attribute selected by the user copying them from the source file
*/
private boolean preserveAttributes(final Path path, final FileStatus refStat) {
FileStatus stat;
try {
stat = outputFs.getFileStatus(path);
} catch (IOException e) {
LOG.warn("Unable to get the status for file=" + path);
return false;
}
try {
if (filesMode > 0 && stat.getPermission().toShort() != filesMode) {
outputFs.setPermission(path, new FsPermission(filesMode));
} else if (!stat.getPermission().equals(refStat.getPermission())) {
outputFs.setPermission(path, refStat.getPermission());
}
} catch (IOException e) {
LOG.error("Unable to set the permission for file=" + path, e);
return false;
}
try {
String user = (filesUser != null) ? filesUser : refStat.getOwner();
String group = (filesGroup != null) ? filesGroup : refStat.getGroup();
if (!(user.equals(stat.getOwner()) && group.equals(stat.getGroup()))) {
outputFs.setOwner(path, user, group);
}
} catch (IOException e) {
LOG.error("Unable to set the owner/group for file=" + path, e);
return false;
}
return true;
}
private boolean copyData(final Context context,
final Path inputPath, final FSDataInputStream in,
final Path outputPath, final FSDataOutputStream out,
final long inputFileSize) {
final String statusMessage = "copied %s/" + StringUtils.humanReadableInt(inputFileSize) +
" (%.3f%%) from " + inputPath + " to " + outputPath;
try {
byte[] buffer = new byte[BUFFER_SIZE];
long totalBytesWritten = 0;
int reportBytes = 0;
int bytesRead;
while ((bytesRead = in.read(buffer)) > 0) {
out.write(buffer, 0, bytesRead);
totalBytesWritten += bytesRead;
reportBytes += bytesRead;
if (reportBytes >= REPORT_SIZE) {
context.getCounter(Counter.BYTES_COPIED).increment(reportBytes);
context.setStatus(String.format(statusMessage,
StringUtils.humanReadableInt(totalBytesWritten),
reportBytes/(float)inputFileSize));
reportBytes = 0;
}
}
context.getCounter(Counter.BYTES_COPIED).increment(reportBytes);
context.setStatus(String.format(statusMessage,
StringUtils.humanReadableInt(totalBytesWritten),
reportBytes/(float)inputFileSize));
// Verify that the written size match
if (totalBytesWritten != inputFileSize) {
LOG.error("number of bytes copied not matching copied=" + totalBytesWritten +
" expected=" + inputFileSize + " for file=" + inputPath);
context.getCounter(Counter.COPY_FAILED).increment(1);
return false;
}
return true;
} catch (IOException e) {
LOG.error("Error copying " + inputPath + " to " + outputPath, e);
context.getCounter(Counter.COPY_FAILED).increment(1);
return false;
}
}
private FSDataInputStream openSourceFile(final Path path) {
try {
if (HFileLink.isHFileLink(path) || StoreFile.isReference(path)) {
return new HFileLink(inputRoot, inputArchive, path).open(inputFs);
} else if (isHLogLinkPath(path)) {
String serverName = path.getParent().getName();
String logName = path.getName();
return new HLogLink(inputRoot, serverName, logName).open(inputFs);
}
return inputFs.open(path);
} catch (IOException e) {
LOG.error("Unable to open source file=" + path, e);
return null;
}
}
private FileStatus getFileStatus(final FileSystem fs, final Path path) {
try {
if (HFileLink.isHFileLink(path) || StoreFile.isReference(path)) {
HFileLink link = new HFileLink(inputRoot, inputArchive, path);
return link.getFileStatus(fs);
} else if (isHLogLinkPath(path)) {
String serverName = path.getParent().getName();
String logName = path.getName();
return new HLogLink(inputRoot, serverName, logName).getFileStatus(fs);
}
return fs.getFileStatus(path);
} catch (IOException e) {
LOG.warn("Unable to get the status for file=" + path);
return null;
}
}
private FileChecksum getFileChecksum(final FileSystem fs, final Path path) {
try {
return fs.getFileChecksum(path);
} catch (IOException e) {
LOG.warn("Unable to get checksum for file=" + path, e);
return null;
}
}
/**
* Check if the two files are equal by looking at the file length,
* and at the checksum (if user has specified the verifyChecksum flag).
*/
private boolean sameFile(final FileStatus inputStat, final FileStatus outputStat) {
// Not matching length
if (inputStat.getLen() != outputStat.getLen()) return false;
// Mark files as equals, since user asked for no checksum verification
if (!verifyChecksum) return true;
// If checksums are not available, files are not the same.
FileChecksum inChecksum = getFileChecksum(inputFs, inputStat.getPath());
if (inChecksum == null) return false;
FileChecksum outChecksum = getFileChecksum(outputFs, outputStat.getPath());
if (outChecksum == null) return false;
return inChecksum.equals(outChecksum);
}
/**
* HLog files are encoded as serverName/logName
* and since all the other files should be in /hbase/table/..path..
* we can rely on the depth, for now.
*/
private static boolean isHLogLinkPath(final Path path) {
return path.depth() == 2;
}
}
/**
* Extract the list of files (HFiles/HLogs) to copy using Map-Reduce.
* @return list of files referenced by the snapshot (pair of path and size)
*/
private List<Pair<Path, Long>> getSnapshotFiles(final FileSystem fs, final Path snapshotDir)
throws IOException {
SnapshotDescription snapshotDesc = SnapshotDescriptionUtils.readSnapshotInfo(fs, snapshotDir);
final List<Pair<Path, Long>> files = new ArrayList<Pair<Path, Long>>();
final String table = snapshotDesc.getTable();
final Configuration conf = getConf();
// Get snapshot files
SnapshotReferenceUtil.visitReferencedFiles(fs, snapshotDir,
new SnapshotReferenceUtil.FileVisitor() {
public void storeFile (final String region, final String family, final String hfile)
throws IOException {
Path path = new Path(family, HFileLink.createHFileLinkName(table, region, hfile));
long size = new HFileLink(conf, path).getFileStatus(fs).getLen();
files.add(new Pair<Path, Long>(path, size));
}
public void recoveredEdits (final String region, final String logfile)
throws IOException {
// copied with the snapshot referenecs
}
public void logFile (final String server, final String logfile)
throws IOException {
long size = new HLogLink(conf, server, logfile).getFileStatus(fs).getLen();
files.add(new Pair<Path, Long>(new Path(server, logfile), size));
}
});
return files;
}
/**
* Given a list of file paths and sizes, create around ngroups in as balanced a way as possible.
* The groups created will have similar amounts of bytes.
* <p>
* The algorithm used is pretty straightforward; the file list is sorted by size,
* and then each group fetch the bigger file available, iterating through groups
* alternating the direction.
*/
static List<List<Path>> getBalancedSplits(final List<Pair<Path, Long>> files, int ngroups) {
// Sort files by size, from small to big
Collections.sort(files, new Comparator<Pair<Path, Long>>() {
public int compare(Pair<Path, Long> a, Pair<Path, Long> b) {
long r = a.getSecond() - b.getSecond();
return (r < 0) ? -1 : ((r > 0) ? 1 : 0);
}
});
// create balanced groups
List<List<Path>> fileGroups = new LinkedList<List<Path>>();
long[] sizeGroups = new long[ngroups];
int hi = files.size() - 1;
int lo = 0;
List<Path> group;
int dir = 1;
int g = 0;
while (hi >= lo) {
if (g == fileGroups.size()) {
group = new LinkedList<Path>();
fileGroups.add(group);
} else {
group = fileGroups.get(g);
}
Pair<Path, Long> fileInfo = files.get(hi--);
// add the hi one
sizeGroups[g] += fileInfo.getSecond();
group.add(fileInfo.getFirst());
// change direction when at the end or the beginning
g += dir;
if (g == ngroups) {
dir = -1;
g = ngroups - 1;
} else if (g < 0) {
dir = 1;
g = 0;
}
}
if (LOG.isDebugEnabled()) {
for (int i = 0; i < sizeGroups.length; ++i) {
LOG.debug("export split=" + i + " size=" + StringUtils.humanReadableInt(sizeGroups[i]));
}
}
return fileGroups;
}
private static Path getInputFolderPath(final FileSystem fs, final Configuration conf)
throws IOException, InterruptedException {
String stagingName = "exportSnapshot-" + EnvironmentEdgeManager.currentTimeMillis();
Path stagingDir = new Path(conf.get(CONF_STAGING_ROOT, fs.getWorkingDirectory().toString())
, stagingName);
fs.mkdirs(stagingDir);
return new Path(stagingDir, INPUT_FOLDER_PREFIX +
String.valueOf(EnvironmentEdgeManager.currentTimeMillis()));
}
/**
* Create the input files, with the path to copy, for the MR job.
* Each input files contains n files, and each input file has a similar amount data to copy.
* The number of input files created are based on the number of mappers provided as argument
* and the number of the files to copy.
*/
private static Path[] createInputFiles(final Configuration conf,
final List<Pair<Path, Long>> snapshotFiles, int mappers)
throws IOException, InterruptedException {
FileSystem fs = FileSystem.get(conf);
Path inputFolderPath = getInputFolderPath(fs, conf);
LOG.debug("Input folder location: " + inputFolderPath);
List<List<Path>> splits = getBalancedSplits(snapshotFiles, mappers);
Path[] inputFiles = new Path[splits.size()];
Text key = new Text();
for (int i = 0; i < inputFiles.length; i++) {
List<Path> files = splits.get(i);
inputFiles[i] = new Path(inputFolderPath, String.format("export-%d.seq", i));
SequenceFile.Writer writer = SequenceFile.createWriter(fs, conf, inputFiles[i],
Text.class, NullWritable.class);
LOG.debug("Input split: " + i);
try {
for (Path file: files) {
LOG.debug(file.toString());
key.set(file.toString());
writer.append(key, NullWritable.get());
}
} finally {
writer.close();
}
}
return inputFiles;
}
/**
* Run Map-Reduce Job to perform the files copy.
*/
private boolean runCopyJob(final Path inputRoot, final Path outputRoot,
final List<Pair<Path, Long>> snapshotFiles, final boolean verifyChecksum,
final String filesUser, final String filesGroup, final int filesMode,
final int mappers) throws IOException, InterruptedException, ClassNotFoundException {
Configuration conf = getConf();
if (filesGroup != null) conf.set(CONF_FILES_GROUP, filesGroup);
if (filesUser != null) conf.set(CONF_FILES_USER, filesUser);
conf.setInt(CONF_FILES_MODE, filesMode);
conf.setBoolean(CONF_CHECKSUM_VERIFY, verifyChecksum);
conf.set(CONF_OUTPUT_ROOT, outputRoot.toString());
conf.set(CONF_INPUT_ROOT, inputRoot.toString());
conf.setInt("mapreduce.job.maps", mappers);
// job.setMapSpeculativeExecution(false)
conf.setBoolean("mapreduce.map.speculative", false);
conf.setBoolean("mapreduce.reduce.speculative", false);
conf.setBoolean("mapred.map.tasks.speculative.execution", false);
conf.setBoolean("mapred.reduce.tasks.speculative.execution", false);
Job job = new Job(conf);
job.setJobName("ExportSnapshot");
job.setJarByClass(ExportSnapshot.class);
job.setMapperClass(ExportMapper.class);
job.setInputFormatClass(SequenceFileInputFormat.class);
job.setOutputFormatClass(NullOutputFormat.class);
job.setNumReduceTasks(0);
for (Path path: createInputFiles(conf, snapshotFiles, mappers)) {
LOG.debug("Add Input Path=" + path);
SequenceFileInputFormat.addInputPath(job, path);
}
return job.waitForCompletion(true);
}
/**
* Execute the export snapshot by copying the snapshot metadata, hfiles and hlogs.
* @return 0 on success, and != 0 upon failure.
*/
@Override
public int run(String[] args) throws Exception {
boolean verifyChecksum = true;
String snapshotName = null;
String filesGroup = null;
String filesUser = null;
Path outputRoot = null;
int filesMode = 0;
int mappers = getConf().getInt("mapreduce.job.maps", 1);
// Process command line args
for (int i = 0; i < args.length; i++) {
String cmd = args[i];
try {
if (cmd.equals("-snapshot")) {
snapshotName = args[++i];
} else if (cmd.equals("-copy-to")) {
outputRoot = new Path(args[++i]);
} else if (cmd.equals("-no-checksum-verify")) {
verifyChecksum = false;
} else if (cmd.equals("-mappers")) {
mappers = Integer.parseInt(args[++i]);
} else if (cmd.equals("-chuser")) {
filesUser = args[++i];
} else if (cmd.equals("-chgroup")) {
filesGroup = args[++i];
} else if (cmd.equals("-chmod")) {
filesMode = Integer.parseInt(args[++i], 8);
} else if (cmd.equals("-h") || cmd.equals("--help")) {
printUsageAndExit();
} else {
System.err.println("UNEXPECTED: " + cmd);
printUsageAndExit();
}
} catch (Exception e) {
printUsageAndExit();
}
}
// Check user options
if (snapshotName == null) {
System.err.println("Snapshot name not provided.");
printUsageAndExit();
}
if (outputRoot == null) {
System.err.println("Destination file-system not provided.");
printUsageAndExit();
}
Configuration conf = getConf();
Path inputRoot = FSUtils.getRootDir(conf);
FileSystem inputFs = FileSystem.get(conf);
FileSystem outputFs = FileSystem.get(outputRoot.toUri(), conf);
Path snapshotDir = SnapshotDescriptionUtils.getCompletedSnapshotDir(snapshotName, inputRoot);
Path snapshotTmpDir = SnapshotDescriptionUtils.getWorkingSnapshotDir(snapshotName, outputRoot);
Path outputSnapshotDir = SnapshotDescriptionUtils.getCompletedSnapshotDir(snapshotName, outputRoot);
// Check if the snapshot already exists
if (outputFs.exists(outputSnapshotDir)) {
System.err.println("The snapshot '" + snapshotName +
"' already exists in the destination: " + outputSnapshotDir);
return 1;
}
// Check if the snapshot already in-progress
if (outputFs.exists(snapshotTmpDir)) {
System.err.println("A snapshot with the same name '" + snapshotName + "' may be in-progress");
System.err.println("Please check " + snapshotTmpDir + ". If the snapshot has completed, ");
System.err.println("consider removing " + snapshotTmpDir + " before retrying export");
return 1;
}
// Step 0 - Extract snapshot files to copy
final List<Pair<Path, Long>> files = getSnapshotFiles(inputFs, snapshotDir);
// Step 1 - Copy fs1:/.snapshot/<snapshot> to fs2:/.snapshot/.tmp/<snapshot>
// The snapshot references must be copied before the hfiles otherwise the cleaner
// will remove them because they are unreferenced.
try {
FileUtil.copy(inputFs, snapshotDir, outputFs, snapshotTmpDir, false, false, conf);
} catch (IOException e) {
System.err.println("Failed to copy the snapshot directory: from=" + snapshotDir +
" to=" + snapshotTmpDir);
e.printStackTrace(System.err);
return 1;
}
// Step 2 - Start MR Job to copy files
// The snapshot references must be copied before the files otherwise the files gets removed
// by the HFileArchiver, since they have no references.
try {
if (files.size() == 0) {
LOG.warn("There are 0 store file to be copied. There may be no data in the table.");
} else {
if (!runCopyJob(inputRoot, outputRoot, files, verifyChecksum,
filesUser, filesGroup, filesMode, mappers)) {
throw new ExportSnapshotException("Snapshot export failed!");
}
}
// Step 3 - Rename fs2:/.snapshot/.tmp/<snapshot> fs2:/.snapshot/<snapshot>
if (!outputFs.rename(snapshotTmpDir, outputSnapshotDir)) {
System.err.println("Snapshot export failed!");
System.err.println("Unable to rename snapshot directory from=" +
snapshotTmpDir + " to=" + outputSnapshotDir);
return 1;
}
return 0;
} catch (Exception e) {
System.err.println("Snapshot export failed!");
e.printStackTrace(System.err);
outputFs.delete(outputSnapshotDir, true);
return 1;
}
}
// ExportSnapshot
private void printUsageAndExit() {
System.err.printf("Usage: bin/hbase %s [options]%n", getClass().getName());
System.err.println(" where [options] are:");
System.err.println(" -h|-help Show this help and exit.");
System.err.println(" -snapshot NAME Snapshot to restore.");
System.err.println(" -copy-to NAME Remote destination hdfs://");
System.err.println(" -no-checksum-verify Do not verify checksum.");
System.err.println(" -chuser USERNAME Change the owner of the files to the specified one.");
System.err.println(" -chgroup GROUP Change the group of the files to the specified one.");
System.err.println(" -chmod MODE Change the permission of the files to the specified one.");
System.err.println(" -mappers Number of mappers to use during the copy (mapreduce.job.maps).");
System.err.println();
System.err.println("Examples:");
System.err.println(" hbase " + getClass() + " \\");
System.err.println(" -snapshot MySnapshot -copy-to hdfs:///srv2:8082/hbase \\");
System.err.println(" -chuser MyUser -chgroup MyGroup -chmod 700 -mappers 16");
System.exit(1);
}
/**
* The guts of the {@link #main} method.
* Call this method to avoid the {@link #main(String[])} System.exit.
* @param args
* @return errCode
* @throws Exception
*/
static int innerMain(final Configuration conf, final String [] args) throws Exception {
return ToolRunner.run(conf, new ExportSnapshot(), args);
}
public static void main(String[] args) throws Exception {
System.exit(innerMain(HBaseConfiguration.create(), args));
}
}