/**
* 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.tools;
import org.apache.commons.logging.Log;
import org.apache.commons.logging.LogFactory;
import org.apache.hadoop.conf.Configuration;
import org.apache.hadoop.conf.Configured;
import org.apache.hadoop.fs.FileSystem;
import org.apache.hadoop.fs.Path;
import org.apache.hadoop.io.Text;
import org.apache.hadoop.mapreduce.Job;
import org.apache.hadoop.mapreduce.JobContext;
import org.apache.hadoop.mapreduce.JobSubmissionFiles;
import org.apache.hadoop.mapreduce.Cluster;
import org.apache.hadoop.tools.CopyListing.*;
import org.apache.hadoop.tools.mapred.CopyMapper;
import org.apache.hadoop.tools.mapred.CopyOutputFormat;
import org.apache.hadoop.tools.util.DistCpUtils;
import org.apache.hadoop.util.Tool;
import org.apache.hadoop.util.ToolRunner;
import java.io.IOException;
import java.util.Random;
/**
* DistCp is the main driver-class for DistCpV2.
* For command-line use, DistCp::main() orchestrates the parsing of command-line
* parameters and the launch of the DistCp job.
* For programmatic use, a DistCp object can be constructed by specifying
* options (in a DistCpOptions object), and DistCp::execute() may be used to
* launch the copy-job. DistCp may alternatively be sub-classed to fine-tune
* behaviour.
*/
public class DistCp extends Configured implements Tool {
private static final Log LOG = LogFactory.getLog(DistCp.class);
private DistCpOptions inputOptions;
private Path metaFolder;
private static final String PREFIX = "_distcp";
private static final String WIP_PREFIX = "._WIP_";
private static final String DISTCP_DEFAULT_XML = "distcp-default.xml";
public static final Random rand = new Random();
private boolean submitted;
private FileSystem jobFS;
/**
* Public Constructor. Creates DistCp object with specified input-parameters.
* (E.g. source-paths, target-location, etc.)
* @param inputOptions Options (indicating source-paths, target-location.)
* @param configuration The Hadoop configuration against which the Copy-mapper must run.
* @throws Exception, on failure.
*/
public DistCp(Configuration configuration, DistCpOptions inputOptions) throws Exception {
Configuration config = new Configuration(configuration);
config.addResource(DISTCP_DEFAULT_XML);
setConf(config);
this.inputOptions = inputOptions;
this.metaFolder = createMetaFolderPath();
}
/**
* To be used with the ToolRunner. Not for public consumption.
*/
private DistCp() {}
/**
* Implementation of Tool::run(). Orchestrates the copy of source file(s)
* to target location, by:
* 1. Creating a list of files to be copied to target.
* 2. Launching a Map-only job to copy the files. (Delegates to execute().)
* @param argv List of arguments passed to DistCp, from the ToolRunner.
* @return On success, it returns 0. Else, -1.
*/
public int run(String[] argv) {
try {
inputOptions = (OptionsParser.parse(argv));
LOG.info("Input Options: " + inputOptions);
} catch (Throwable e) {
LOG.error("Invalid arguments: ", e);
System.err.println("Invalid arguments: " + e.getMessage());
OptionsParser.usage();
return DistCpConstants.INVALID_ARGUMENT;
}
try {
execute();
} catch (InvalidInputException e) {
LOG.error("Invalid input: ", e);
return DistCpConstants.INVALID_ARGUMENT;
} catch (DuplicateFileException e) {
LOG.error("Duplicate files in input path: ", e);
return DistCpConstants.DUPLICATE_INPUT;
} catch (Exception e) {
LOG.error("Exception encountered ", e);
return DistCpConstants.UNKNOWN_ERROR;
}
return DistCpConstants.SUCCESS;
}
/**
* Implements the core-execution. Creates the file-list for copy,
* and launches the Hadoop-job, to do the copy.
* @return Job handle
* @throws Exception, on failure.
*/
public Job execute() throws Exception {
assert inputOptions != null;
assert getConf() != null;
Job job = null;
try {
metaFolder = createMetaFolderPath();
jobFS = metaFolder.getFileSystem(getConf());
job = createJob();
createInputFileListing(job);
job.submit();
submitted = true;
} finally {
if (!submitted) {
cleanup();
}
}
String jobID = job.getJobID().toString();
job.getConfiguration().set(DistCpConstants.CONF_LABEL_DISTCP_JOB_ID, jobID);
LOG.info("DistCp job-id: " + jobID);
if (inputOptions.shouldBlock()) {
job.waitForCompletion(true);
}
return job;
}
/**
* Create Job object for submitting it, with all the configuration
*
* @return Reference to job object.
* @throws IOException - Exception if any
*/
private Job createJob() throws IOException {
String jobName = "distcp";
String userChosenName = getConf().get(JobContext.JOB_NAME);
if (userChosenName != null)
jobName += ": " + userChosenName;
Job job = Job.getInstance(getConf());
job.setJobName(jobName);
job.setInputFormatClass(DistCpUtils.getStrategy(getConf(), inputOptions));
job.setJarByClass(CopyMapper.class);
configureOutputFormat(job);
job.setMapperClass(CopyMapper.class);
job.setNumReduceTasks(0);
job.setMapOutputKeyClass(Text.class);
job.setMapOutputValueClass(Text.class);
job.setOutputFormatClass(CopyOutputFormat.class);
job.getConfiguration().set(JobContext.MAP_SPECULATIVE, "false");
job.getConfiguration().set(JobContext.NUM_MAPS,
String.valueOf(inputOptions.getMaxMaps()));
if (inputOptions.getSslConfigurationFile() != null) {
setupSSLConfig(job);
}
inputOptions.appendToConf(job.getConfiguration());
return job;
}
/**
* Setup ssl configuration on the job configuration to enable hsftp access
* from map job. Also copy the ssl configuration file to Distributed cache
*
* @param job - Reference to job's handle
* @throws java.io.IOException - Exception if unable to locate ssl config file
*/
private void setupSSLConfig(Job job) throws IOException {
Configuration configuration = job.getConfiguration();
Path sslConfigPath = new Path(configuration.
getResource(inputOptions.getSslConfigurationFile()).toString());
addSSLFilesToDistCache(job, sslConfigPath);
configuration.set(DistCpConstants.CONF_LABEL_SSL_CONF, sslConfigPath.getName());
configuration.set(DistCpConstants.CONF_LABEL_SSL_KEYSTORE, sslConfigPath.getName());
}
/**
* Add SSL files to distributed cache. Trust store, key store and ssl config xml
*
* @param job - Job handle
* @param sslConfigPath - ssl Configuration file specified through options
* @throws IOException - If any
*/
private void addSSLFilesToDistCache(Job job,
Path sslConfigPath) throws IOException {
Configuration configuration = job.getConfiguration();
FileSystem localFS = FileSystem.getLocal(configuration);
Configuration sslConf = new Configuration(false);
sslConf.addResource(sslConfigPath);
Path localStorePath = getLocalStorePath(sslConf,
DistCpConstants.CONF_LABEL_SSL_TRUST_STORE_LOCATION);
job.addCacheFile(localStorePath.makeQualified(localFS.getUri(),
localFS.getWorkingDirectory()).toUri());
configuration.set(DistCpConstants.CONF_LABEL_SSL_TRUST_STORE_LOCATION,
localStorePath.getName());
localStorePath = getLocalStorePath(sslConf,
DistCpConstants.CONF_LABEL_SSL_KEY_STORE_LOCATION);
job.addCacheFile(localStorePath.makeQualified(localFS.getUri(),
localFS.getWorkingDirectory()).toUri());
configuration.set(DistCpConstants.CONF_LABEL_SSL_KEY_STORE_LOCATION,
localStorePath.getName());
job.addCacheFile(sslConfigPath.makeQualified(localFS.getUri(),
localFS.getWorkingDirectory()).toUri());
}
/**
* Get Local Trust store/key store path
*
* @param sslConf - Config from SSL Client xml
* @param storeKey - Key for either trust store or key store
* @return - Path where the store is present
* @throws IOException -If any
*/
private Path getLocalStorePath(Configuration sslConf, String storeKey) throws IOException {
if (sslConf.get(storeKey) != null) {
return new Path(sslConf.get(storeKey));
} else {
throw new IOException("Store for " + storeKey + " is not set in " +
inputOptions.getSslConfigurationFile());
}
}
/**
* Setup output format appropriately
*
* @param job - Job handle
* @throws IOException - Exception if any
*/
private void configureOutputFormat(Job job) throws IOException {
final Configuration configuration = job.getConfiguration();
Path targetPath = inputOptions.getTargetPath();
FileSystem targetFS = targetPath.getFileSystem(configuration);
targetPath = targetPath.makeQualified(targetFS.getUri(),
targetFS.getWorkingDirectory());
if (inputOptions.shouldAtomicCommit()) {
Path workDir = inputOptions.getAtomicWorkPath();
if (workDir == null) {
workDir = targetPath.getParent();
}
workDir = new Path(workDir, WIP_PREFIX + targetPath.getName()
+ rand.nextInt());
FileSystem workFS = workDir.getFileSystem(configuration);
if (!DistCpUtils.compareFs(targetFS, workFS)) {
throw new IllegalArgumentException("Work path " + workDir +
" and target path " + targetPath + " are in different file system");
}
CopyOutputFormat.setWorkingDirectory(job, workDir);
} else {
CopyOutputFormat.setWorkingDirectory(job, targetPath);
}
CopyOutputFormat.setCommitDirectory(job, targetPath);
Path logPath = inputOptions.getLogPath();
if (logPath == null) {
logPath = new Path(metaFolder, "_logs");
} else {
LOG.info("DistCp job log path: " + logPath);
}
CopyOutputFormat.setOutputPath(job, logPath);
}
/**
* Create input listing by invoking an appropriate copy listing
* implementation. Also add delegation tokens for each path
* to job's credential store
*
* @param job - Handle to job
* @return Returns the path where the copy listing is created
* @throws IOException - If any
*/
private Path createInputFileListing(Job job) throws IOException {
Path fileListingPath = getFileListingPath();
CopyListing copyListing = CopyListing.getCopyListing(job.getConfiguration(),
job.getCredentials(), inputOptions);
copyListing.buildListing(fileListingPath, inputOptions);
return fileListingPath;
}
/**
* Get default name of the copy listing file. Use the meta folder
* to create the copy listing file
*
* @return - Path where the copy listing file has to be saved
* @throws IOException - Exception if any
*/
private Path getFileListingPath() throws IOException {
String fileListPathStr = metaFolder + "/fileList.seq";
Path path = new Path(fileListPathStr);
return new Path(path.toUri().normalize().toString());
}
/**
* Create a default working folder for the job, under the
* job staging directory
*
* @return Returns the working folder information
* @throws Exception - EXception if any
*/
private Path createMetaFolderPath() throws Exception {
Configuration configuration = getConf();
Path stagingDir = JobSubmissionFiles.getStagingDir(
new Cluster(configuration), configuration);
Path metaFolderPath = new Path(stagingDir, PREFIX + String.valueOf(rand.nextInt()));
if (LOG.isDebugEnabled())
LOG.debug("Meta folder location: " + metaFolderPath);
configuration.set(DistCpConstants.CONF_LABEL_META_FOLDER, metaFolderPath.toString());
return metaFolderPath;
}
/**
* Main function of the DistCp program. Parses the input arguments (via OptionsParser),
* and invokes the DistCp::run() method, via the ToolRunner.
* @param argv Command-line arguments sent to DistCp.
*/
public static void main(String argv[]) {
try {
DistCp distCp = new DistCp();
Cleanup CLEANUP = new Cleanup(distCp);
Runtime.getRuntime().addShutdownHook(CLEANUP);
System.exit(ToolRunner.run(getDefaultConf(), distCp, argv));
}
catch (Exception e) {
LOG.error("Couldn't complete DistCp operation: ", e);
System.exit(DistCpConstants.UNKNOWN_ERROR);
}
}
/**
* Loads properties from distcp-default.xml into configuration
* object
* @return Configuration which includes properties from distcp-default.xml
*/
private static Configuration getDefaultConf() {
Configuration config = new Configuration();
config.addResource(DISTCP_DEFAULT_XML);
return config;
}
private synchronized void cleanup() {
try {
if (metaFolder == null) return;
jobFS.delete(metaFolder, true);
metaFolder = null;
} catch (IOException e) {
LOG.error("Unable to cleanup meta folder: " + metaFolder, e);
}
}
private boolean isSubmitted() {
return submitted;
}
private static class Cleanup extends Thread {
private final DistCp distCp;
public Cleanup(DistCp distCp) {
this.distCp = distCp;
}
@Override
public void run() {
if (distCp.isSubmitted()) return;
distCp.cleanup();
}
}
}