Java tutorial
package com.pinterest.hdfsbackup.distcp; /** * 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. */ import org.apache.commons.logging.Log; import org.apache.commons.logging.LogFactory; import org.apache.hadoop.conf.Configuration; import org.apache.hadoop.fs.*; import org.apache.hadoop.fs.FileSystem; import org.apache.hadoop.fs.permission.FsPermission; import org.apache.hadoop.hdfs.protocol.QuotaExceededException; import org.apache.hadoop.io.*; import org.apache.hadoop.ipc.RemoteException; import org.apache.hadoop.mapred.*; import org.apache.hadoop.security.AccessControlException; import org.apache.hadoop.util.StringUtils; import org.apache.hadoop.util.Tool; import org.apache.hadoop.util.ToolRunner; import java.io.*; import java.util.*; /** * A Map-reduce program to recursively copy directories between * different file-systems. */ public class DistCp implements Tool { public static final Log LOG = LogFactory.getLog(DistCp.class); private static final String NAME = "distcp"; private static final String usage = NAME + " [OPTIONS] <srcurl>* <desturl>" + "\n\nOPTIONS:" + "\n-p[rbugp] Preserve status" + "\n r: replication number" + "\n b: block size" + "\n u: user" + "\n g: group" + "\n p: permission" + "\n -p alone is equivalent to -prbugp" + "\n-i Ignore failures" + "\n-log <logdir> Write logs to <logdir>" + "\n-m <num_maps> Maximum number of simultaneous copies" + "\n-overwrite Overwrite destination" + "\n-update Overwrite if src size different from dst size" + "\n-f <urilist_uri> Use list at <urilist_uri> as src list" + "\n-filelimit <n> Limit the total number of files to be <= n" + "\n-sizelimit <n> Limit the total size to be <= n bytes" + "\n-delete Delete the files existing in the dst but not in src" + "\n-mapredSslConf <f> Filename of SSL configuration for mapper task" + "\n\nNOTE 1: if -overwrite or -update are set, each source URI is " + "\n interpreted as an isomorphic update to an existing directory." + "\nFor example:" + "\nhadoop " + NAME + " -p -update \"hdfs://A:8020/user/foo/bar\" " + "\"hdfs://B:8020/user/foo/baz\"\n" + "\n would update all descendants of 'baz' also in 'bar'; it would " + "\n *not* update /user/foo/baz/bar" + "\n\nNOTE 2: The parameter <n> in -filelimit and -sizelimit can be " + "\n specified with symbolic representation. For examples," + "\n 1230k = 1230 * 1024 = 1259520" + "\n 891g = 891 * 1024^3 = 956703965184" + "\n"; private static final long BYTES_PER_MAP = 256 * 1024 * 1024; private static final int MAX_MAPS_PER_NODE = 20; private static final int SYNC_FILE_MAX = 10; static enum Counter { COPY, SKIP, FAIL, BYTESCOPIED, BYTESEXPECTED } static enum Options { DELETE("-delete", NAME + ".delete"), FILE_LIMIT("-filelimit", NAME + ".limit.file"), SIZE_LIMIT( "-sizelimit", NAME + ".limit.size"), IGNORE_READ_FAILURES("-i", NAME + ".ignore.read.failures"), PRESERVE_STATUS( "-p", NAME + ".preserve.status"), OVERWRITE("-overwrite", NAME + ".overwrite.always"), UPDATE("-update", NAME + ".overwrite.ifnewer"); final String cmd, propertyname; private Options(String cmd, String propertyname) { this.cmd = cmd; this.propertyname = propertyname; } private long parseLong(String[] args, int offset) { if (offset == args.length) { throw new IllegalArgumentException("<n> not specified in " + cmd); } long n = StringUtils.TraditionalBinaryPrefix.string2long(args[offset]); if (n <= 0) { throw new IllegalArgumentException("n = " + n + " <= 0 in " + cmd); } return n; } } static enum FileAttribute { BLOCK_SIZE, REPLICATION, USER, GROUP, PERMISSION; final char symbol; private FileAttribute() { symbol = toString().toLowerCase().charAt(0); } static EnumSet<FileAttribute> parse(String s) { if (s == null || s.length() == 0) { return EnumSet.allOf(FileAttribute.class); } EnumSet<FileAttribute> set = EnumSet.noneOf(FileAttribute.class); FileAttribute[] attributes = values(); for (char c : s.toCharArray()) { int i = 0; for (; i < attributes.length && c != attributes[i].symbol; i++) ; if (i < attributes.length) { if (!set.contains(attributes[i])) { set.add(attributes[i]); } else { throw new IllegalArgumentException( "There are more than one '" + attributes[i].symbol + "' in " + s); } } else { throw new IllegalArgumentException("'" + c + "' in " + s + " is undefined."); } } return set; } } static final String TMP_DIR_LABEL = NAME + ".tmp.dir"; static final String DST_DIR_LABEL = NAME + ".dest.path"; static final String JOB_DIR_LABEL = NAME + ".job.dir"; static final String MAX_MAPS_LABEL = NAME + ".max.map.tasks"; static final String SRC_LIST_LABEL = NAME + ".src.list"; static final String SRC_COUNT_LABEL = NAME + ".src.count"; static final String TOTAL_SIZE_LABEL = NAME + ".total.size"; static final String DST_DIR_LIST_LABEL = NAME + ".dst.dir.list"; static final String BYTES_PER_MAP_LABEL = NAME + ".bytes.per.map"; static final String PRESERVE_STATUS_LABEL = Options.PRESERVE_STATUS.propertyname + ".value"; private JobConf conf; public void setConf(Configuration conf) { if (conf instanceof JobConf) { this.conf = (JobConf) conf; } else { this.conf = new JobConf(conf); } } public Configuration getConf() { return conf; } public DistCp(Configuration conf) { setConf(conf); } /** * An input/output pair of filenames. */ static class FilePair implements Writable { FileStatus input = new FileStatus(); String output; FilePair() { } FilePair(FileStatus input, String output) { this.input = input; this.output = output; } public void readFields(DataInput in) throws IOException { input.readFields(in); output = Text.readString(in); } public void write(DataOutput out) throws IOException { input.write(out); Text.writeString(out, output); } public String toString() { return input + " : " + output; } } /** * InputFormat of a distcp job responsible for generating splits of the src * file list. */ static class CopyInputFormat implements InputFormat<Text, Text> { /** * Produce splits such that each is no greater than the quotient of the * total size and the number of splits requested. * @param job The handle to the JobConf object * @param numSplits Number of splits requested */ public InputSplit[] getSplits(JobConf job, int numSplits) throws IOException { int cnfiles = job.getInt(SRC_COUNT_LABEL, -1); long cbsize = job.getLong(TOTAL_SIZE_LABEL, -1); String srcfilelist = job.get(SRC_LIST_LABEL, ""); if (cnfiles < 0 || cbsize < 0 || "".equals(srcfilelist)) { throw new RuntimeException("Invalid metadata: #files(" + cnfiles + ") total_size(" + cbsize + ") listuri(" + srcfilelist + ")"); } Path src = new Path(srcfilelist); FileSystem fs = src.getFileSystem(job); FileStatus srcst = fs.getFileStatus(src); ArrayList<FileSplit> splits = new ArrayList<FileSplit>(numSplits); LongWritable key = new LongWritable(); FilePair value = new FilePair(); final long targetsize = cbsize / numSplits; long pos = 0L; long last = 0L; long acc = 0L; long cbrem = srcst.getLen(); SequenceFile.Reader sl = null; try { sl = new SequenceFile.Reader(fs, src, job); for (; sl.next(key, value); last = sl.getPosition()) { // if adding this split would put this split past the target size, // cut the last split and put this next file in the next split. if (acc + key.get() > targetsize && acc != 0) { long splitsize = last - pos; splits.add(new FileSplit(src, pos, splitsize, (String[]) null)); cbrem -= splitsize; pos = last; acc = 0L; } acc += key.get(); } } finally { checkAndClose(sl); } if (cbrem != 0) { splits.add(new FileSplit(src, pos, cbrem, (String[]) null)); } return splits.toArray(new FileSplit[splits.size()]); } /** * Returns a reader for this split of the src file list. */ public RecordReader<Text, Text> getRecordReader(InputSplit split, JobConf job, Reporter reporter) throws IOException { return new SequenceFileRecordReader<Text, Text>(job, (FileSplit) split); } } /** * FSCopyFilesMapper: The mapper for copying files between FileSystems. */ static class CopyFilesMapper implements Mapper<LongWritable, FilePair, WritableComparable<?>, Text> { // config private int sizeBuf = 128 * 1024; private FileSystem destFileSys = null; private boolean ignoreReadFailures; private boolean preserve_status; private EnumSet<FileAttribute> preseved; private boolean overwrite; private boolean update; private Path destPath = null; private byte[] buffer = null; private JobConf job; // stats private int failcount = 0; private int skipcount = 0; private int copycount = 0; private String getCountString() { return "Copied: " + copycount + " Skipped: " + skipcount + " Failed: " + failcount; } private void updateStatus(Reporter reporter) { reporter.setStatus(getCountString()); } /** * Return true if dst should be replaced by src and the update flag is set. * Right now, this merely checks that the src and dst len are not equal. * This should be improved on once modification times, CRCs, etc. can * be meaningful in this context. * @throws IOException */ private boolean needsUpdate(FileStatus srcstatus, FileSystem dstfs, Path dstpath) throws IOException { return update && !sameFile(srcstatus.getPath().getFileSystem(job), srcstatus, dstfs, dstpath); } private FSDataOutputStream create(Path f, Reporter reporter, FileStatus srcstat) throws IOException { if (destFileSys.exists(f)) { destFileSys.delete(f, false); } if (!preserve_status) { return destFileSys.create(f, true, sizeBuf, reporter); } FsPermission permission = preseved.contains(FileAttribute.PERMISSION) ? srcstat.getPermission() : null; short replication = preseved.contains(FileAttribute.REPLICATION) ? srcstat.getReplication() : destFileSys.getDefaultReplication(); long blockSize = preseved.contains(FileAttribute.BLOCK_SIZE) ? srcstat.getBlockSize() : destFileSys.getDefaultBlockSize(); return destFileSys.create(f, permission, true, sizeBuf, replication, blockSize, reporter); } /** * Copy a file to a destination. * @param srcstat src path and metadata * @param dstpath dst path * @param reporter */ private void copy(FileStatus srcstat, Path relativedst, OutputCollector<WritableComparable<?>, Text> outc, Reporter reporter) throws IOException { Path absdst = new Path(destPath, relativedst); int totfiles = job.getInt(SRC_COUNT_LABEL, -1); assert totfiles >= 0 : "Invalid file count " + totfiles; // if a directory, ensure created even if empty if (srcstat.isDir()) { if (destFileSys.exists(absdst)) { if (!destFileSys.getFileStatus(absdst).isDir()) { throw new IOException("Failed to mkdirs: " + absdst + " is a file."); } } else if (!destFileSys.mkdirs(absdst)) { throw new IOException("Failed to mkdirs " + absdst); } // TODO: when modification times can be set, directories should be // emitted to reducers so they might be preserved. Also, mkdirs does // not currently return an error when the directory already exists; // if this changes, all directory work might as well be done in reduce return; } if (destFileSys.exists(absdst) && !overwrite && !needsUpdate(srcstat, destFileSys, absdst)) { outc.collect(null, new Text("SKIP: " + srcstat.getPath())); ++skipcount; reporter.incrCounter(Counter.SKIP, 1); updateStatus(reporter); return; } Path tmpfile = new Path(job.get(TMP_DIR_LABEL), relativedst); long cbcopied = 0L; FSDataInputStream in = null; FSDataOutputStream out = null; try { // open src file try { in = srcstat.getPath().getFileSystem(job).open(srcstat.getPath()); } catch (IOException e) { LOG.error("Failed to open src file " + srcstat.getPath() + ", ignore and return"); in = null; return; } reporter.incrCounter(Counter.BYTESEXPECTED, srcstat.getLen()); // open tmp file out = create(tmpfile, reporter, srcstat); // copy file for (int cbread; (cbread = in.read(buffer)) >= 0;) { out.write(buffer, 0, cbread); cbcopied += cbread; reporter.setStatus(String.format("%.2f ", cbcopied * 100.0 / srcstat.getLen()) + absdst + " [ " + StringUtils.humanReadableInt(cbcopied) + " / " + StringUtils.humanReadableInt(srcstat.getLen()) + " ]"); } } finally { checkAndClose(in); checkAndClose(out); } if (cbcopied != srcstat.getLen()) { if (srcstat.getLen() == 0 && cbcopied > 0) { LOG.info("most likely see a WAL file corruption: " + srcstat.getPath()); } else { throw new IOException("File size not matched: copied " + bytesString(cbcopied) + " to tmpfile (=" + tmpfile + ") but expected " + bytesString(srcstat.getLen()) + " from " + srcstat.getPath()); } } else { if (totfiles == 1) { // Copying a single file; use dst path provided by user as destination // rather than destination directory, if a file Path dstparent = absdst.getParent(); if (!(destFileSys.exists(dstparent) && destFileSys.getFileStatus(dstparent).isDir())) { absdst = dstparent; } } if (destFileSys.exists(absdst) && destFileSys.getFileStatus(absdst).isDir()) { throw new IOException(absdst + " is a directory"); } if (!destFileSys.mkdirs(absdst.getParent())) { throw new IOException("Failed to craete parent dir: " + absdst.getParent()); } rename(tmpfile, absdst); FileStatus dststat = destFileSys.getFileStatus(absdst); if (dststat.getLen() != srcstat.getLen()) { destFileSys.delete(absdst, false); throw new IOException("File size not matched: copied " + bytesString(dststat.getLen()) + " to dst (=" + absdst + ") but expected " + bytesString(srcstat.getLen()) + " from " + srcstat.getPath()); } updatePermissions(srcstat, dststat); } // report at least once for each file ++copycount; reporter.incrCounter(Counter.BYTESCOPIED, cbcopied); reporter.incrCounter(Counter.COPY, 1); updateStatus(reporter); } /** rename tmp to dst, delete dst if already exists */ private void rename(Path tmp, Path dst) throws IOException { try { if (destFileSys.exists(dst)) { destFileSys.delete(dst, true); } if (!destFileSys.rename(tmp, dst)) { throw new IOException(); } } catch (IOException cause) { throw (IOException) new IOException( "Fail to rename tmp file (=" + tmp + ") to destination file (=" + dst + ")") .initCause(cause); } } private void updatePermissions(FileStatus src, FileStatus dst) throws IOException { if (preserve_status) { DistCp.updatePermissions(src, dst, preseved, destFileSys); } } static String bytesString(long b) { return b + " bytes (" + StringUtils.humanReadableInt(b) + ")"; } /** Mapper configuration. * Extracts source and destination file system, as well as * top-level paths on source and destination directories. * Gets the named file systems, to be used later in map. */ public void configure(JobConf job) { destPath = new Path(job.get(DST_DIR_LABEL, "/")); try { destFileSys = destPath.getFileSystem(job); } catch (IOException ex) { throw new RuntimeException("Unable to get the named file system.", ex); } sizeBuf = job.getInt("copy.buf.size", 128 * 1024); buffer = new byte[sizeBuf]; ignoreReadFailures = job.getBoolean(Options.IGNORE_READ_FAILURES.propertyname, false); preserve_status = job.getBoolean(Options.PRESERVE_STATUS.propertyname, false); if (preserve_status) { preseved = FileAttribute.parse(job.get(PRESERVE_STATUS_LABEL)); } update = job.getBoolean(Options.UPDATE.propertyname, false); overwrite = !update && job.getBoolean(Options.OVERWRITE.propertyname, false); this.job = job; } /** Map method. Copies one file from source file system to destination. * @param key src len * @param value FilePair (FileStatus src, Path dst) * @param out Log of failed copies * @param reporter */ public void map(LongWritable key, FilePair value, OutputCollector<WritableComparable<?>, Text> out, Reporter reporter) throws IOException { final FileStatus srcstat = value.input; final Path relativedst = new Path(value.output); try { copy(srcstat, relativedst, out, reporter); } catch (IOException e) { ++failcount; reporter.incrCounter(Counter.FAIL, 1); updateStatus(reporter); final String sfailure = "FAIL " + relativedst + " : " + StringUtils.stringifyException(e); out.collect(null, new Text(sfailure)); LOG.info(sfailure); try { for (int i = 0; i < 3; ++i) { try { final Path tmp = new Path(job.get(TMP_DIR_LABEL), relativedst); if (destFileSys.delete(tmp, true)) break; } catch (Throwable ex) { // ignore, we are just cleaning up LOG.debug("Ignoring cleanup exception", ex); } // update status, so we don't get timed out updateStatus(reporter); Thread.sleep(3 * 1000); } } catch (InterruptedException inte) { throw (IOException) new IOException().initCause(inte); } } finally { updateStatus(reporter); } } public void close() throws IOException { if (0 == failcount || ignoreReadFailures) { return; } throw new IOException(getCountString()); } } private static List<Path> fetchFileList(Configuration conf, Path srcList) throws IOException { List<Path> result = new ArrayList<Path>(); FileSystem fs = srcList.getFileSystem(conf); BufferedReader input = null; try { input = new BufferedReader(new InputStreamReader(fs.open(srcList))); String line = input.readLine(); while (line != null) { result.add(new Path(line)); line = input.readLine(); } } finally { checkAndClose(input); } return result; } @Deprecated public static void copy(Configuration conf, String srcPath, String destPath, Path logPath, boolean srcAsList, boolean ignoreReadFailures) throws IOException { final Path src = new Path(srcPath); List<Path> tmp = new ArrayList<Path>(); if (srcAsList) { tmp.addAll(fetchFileList(conf, src)); } else { tmp.add(src); } EnumSet<Options> flags = ignoreReadFailures ? EnumSet.of(Options.IGNORE_READ_FAILURES) : EnumSet.noneOf(Options.class); final Path dst = new Path(destPath); copy(conf, new Arguments(tmp, dst, logPath, flags, null, Long.MAX_VALUE, Long.MAX_VALUE, null)); } /** Sanity check for srcPath */ private static void checkSrcPath(Configuration conf, List<Path> srcPaths) throws IOException { List<IOException> rslt = new ArrayList<IOException>(); for (Path p : srcPaths) { FileSystem fs = p.getFileSystem(conf); if (!fs.exists(p)) { rslt.add(new IOException("Input source " + p + " does not exist.")); } } if (!rslt.isEmpty()) { throw new InvalidInputException(rslt); } } /** * Driver to copy srcPath to destPath depending on required protocol. * @param args arguments */ static void copy(final Configuration conf, final Arguments args) throws IOException { LOG.info("srcPaths=" + args.srcs); LOG.info("destPath=" + args.dst); checkSrcPath(conf, args.srcs); JobConf job = createJobConf(conf); if (args.preservedAttributes != null) { job.set(PRESERVE_STATUS_LABEL, args.preservedAttributes); } if (args.mapredSslConf != null) { job.set("dfs.https.client.keystore.resource", args.mapredSslConf); } //Initialize the mapper try { setup(conf, job, args); JobClient.runJob(job); finalize(conf, job, args.dst, args.preservedAttributes); } finally { //delete tmp fullyDelete(job.get(TMP_DIR_LABEL), job); //delete jobDirectory fullyDelete(job.get(JOB_DIR_LABEL), job); } } private static void updatePermissions(FileStatus src, FileStatus dst, EnumSet<FileAttribute> preseved, FileSystem destFileSys) throws IOException { String owner = null; String group = null; if (preseved.contains(FileAttribute.USER) && !src.getOwner().equals(dst.getOwner())) { owner = src.getOwner(); } if (preseved.contains(FileAttribute.GROUP) && !src.getGroup().equals(dst.getGroup())) { group = src.getGroup(); } if (owner != null || group != null) { destFileSys.setOwner(dst.getPath(), owner, group); } if (preseved.contains(FileAttribute.PERMISSION) && !src.getPermission().equals(dst.getPermission())) { destFileSys.setPermission(dst.getPath(), src.getPermission()); } } static private void finalize(Configuration conf, JobConf jobconf, final Path destPath, String presevedAttributes) throws IOException { if (presevedAttributes == null) { return; } EnumSet<FileAttribute> preseved = FileAttribute.parse(presevedAttributes); if (!preseved.contains(FileAttribute.USER) && !preseved.contains(FileAttribute.GROUP) && !preseved.contains(FileAttribute.PERMISSION)) { return; } FileSystem dstfs = destPath.getFileSystem(conf); Path dstdirlist = new Path(jobconf.get(DST_DIR_LIST_LABEL)); SequenceFile.Reader in = null; try { in = new SequenceFile.Reader(dstdirlist.getFileSystem(jobconf), dstdirlist, jobconf); Text dsttext = new Text(); FilePair pair = new FilePair(); for (; in.next(dsttext, pair);) { Path absdst = new Path(destPath, pair.output); updatePermissions(pair.input, dstfs.getFileStatus(absdst), preseved, dstfs); } } finally { checkAndClose(in); } } static private class Arguments { final List<Path> srcs; final Path dst; final Path log; final EnumSet<Options> flags; final String preservedAttributes; final long filelimit; final long sizelimit; final String mapredSslConf; /** * Arguments for distcp * @param srcs List of source paths * @param dst Destination path * @param log Log output directory * @param flags Command-line flags * @param preservedAttributes Preserved attributes * @param filelimit File limit * @param sizelimit Size limit */ Arguments(List<Path> srcs, Path dst, Path log, EnumSet<Options> flags, String preservedAttributes, long filelimit, long sizelimit, String mapredSslConf) { this.srcs = srcs; this.dst = dst; this.log = log; this.flags = flags; this.preservedAttributes = preservedAttributes; this.filelimit = filelimit; this.sizelimit = sizelimit; this.mapredSslConf = mapredSslConf; if (LOG.isTraceEnabled()) { LOG.trace("this = " + this); } } static Arguments valueOf(String[] args, Configuration conf) throws IOException { List<Path> srcs = new ArrayList<Path>(); Path dst = null; Path log = null; EnumSet<Options> flags = EnumSet.noneOf(Options.class); String presevedAttributes = null; String mapredSslConf = null; long filelimit = Long.MAX_VALUE; long sizelimit = Long.MAX_VALUE; for (int idx = 0; idx < args.length; idx++) { Options[] opt = Options.values(); int i = 0; for (; i < opt.length && !args[idx].startsWith(opt[i].cmd); i++) ; if (i < opt.length) { flags.add(opt[i]); if (opt[i] == Options.PRESERVE_STATUS) { presevedAttributes = args[idx].substring(2); FileAttribute.parse(presevedAttributes); //validation } else if (opt[i] == Options.FILE_LIMIT) { filelimit = Options.FILE_LIMIT.parseLong(args, ++idx); } else if (opt[i] == Options.SIZE_LIMIT) { sizelimit = Options.SIZE_LIMIT.parseLong(args, ++idx); } } else if ("-f".equals(args[idx])) { if (++idx == args.length) { throw new IllegalArgumentException("urilist_uri not specified in -f"); } srcs.addAll(fetchFileList(conf, new Path(args[idx]))); } else if ("-log".equals(args[idx])) { if (++idx == args.length) { throw new IllegalArgumentException("logdir not specified in -log"); } log = new Path(args[idx]); } else if ("-mapredSslConf".equals(args[idx])) { if (++idx == args.length) { throw new IllegalArgumentException("ssl conf file not specified in -mapredSslConf"); } mapredSslConf = args[idx]; } else if ("-m".equals(args[idx])) { if (++idx == args.length) { throw new IllegalArgumentException("num_maps not specified in -m"); } try { conf.setInt(MAX_MAPS_LABEL, Integer.valueOf(args[idx])); } catch (NumberFormatException e) { throw new IllegalArgumentException("Invalid argument to -m: " + args[idx]); } } else if ('-' == args[idx].codePointAt(0)) { throw new IllegalArgumentException("Invalid switch " + args[idx]); } else if (idx == args.length - 1) { dst = new Path(args[idx]); } else { srcs.add(new Path(args[idx])); } } // mandatory command-line parameters if (srcs.isEmpty() || dst == null) { throw new IllegalArgumentException("Missing " + (dst == null ? "dst path" : "src")); } // incompatible command-line flags final boolean isOverwrite = flags.contains(Options.OVERWRITE); final boolean isUpdate = flags.contains(Options.UPDATE); final boolean isDelete = flags.contains(Options.DELETE); if (isOverwrite && isUpdate) { throw new IllegalArgumentException("Conflicting overwrite policies"); } if (isDelete && !isOverwrite && !isUpdate) { throw new IllegalArgumentException(Options.DELETE.cmd + " must be specified with " + Options.OVERWRITE + " or " + Options.UPDATE + "."); } return new Arguments(srcs, dst, log, flags, presevedAttributes, filelimit, sizelimit, mapredSslConf); } /** {@inheritDoc} */ public String toString() { return getClass().getName() + "{" + "\n srcs = " + srcs + "\n dst = " + dst + "\n log = " + log + "\n flags = " + flags + "\n preservedAttributes = " + preservedAttributes + "\n filelimit = " + filelimit + "\n sizelimit = " + sizelimit + "\n mapredSslConf = " + mapredSslConf + "\n}"; } } /** * This is the main driver for recursively copying directories * across file systems. It takes at least two cmdline parameters. A source * URL and a destination URL. It then essentially does an "ls -lR" on the * source URL, and writes the output in a round-robin manner to all the map * input files. The mapper actually copies the files allotted to it. The * reduce is empty. */ public int run(String[] args) { try { copy(conf, Arguments.valueOf(args, conf)); return 0; } catch (IllegalArgumentException e) { System.err.println(StringUtils.stringifyException(e) + "\n" + usage); ToolRunner.printGenericCommandUsage(System.err); return -1; } catch (DuplicationException e) { System.err.println(StringUtils.stringifyException(e)); return DuplicationException.ERROR_CODE; } catch (RemoteException e) { final IOException unwrapped = e.unwrapRemoteException(FileNotFoundException.class, AccessControlException.class, QuotaExceededException.class); System.err.println(StringUtils.stringifyException(unwrapped)); return -3; } catch (Exception e) { System.err.println("With failures, global counters are inaccurate; " + "consider running with -i"); System.err.println("Copy failed: " + StringUtils.stringifyException(e)); return -999; } } public static void main(String[] args) throws Exception { JobConf job = new JobConf(DistCp.class); DistCp distcp = new DistCp(job); int res = ToolRunner.run(distcp, args); System.exit(res); } /** * Make a path relative with respect to a root path. * absPath is always assumed to descend from root. * Otherwise returned path is null. */ static String makeRelative(Path root, Path absPath) { if (!absPath.isAbsolute()) { throw new IllegalArgumentException("!absPath.isAbsolute(), absPath=" + absPath); } String p = absPath.toUri().getPath(); StringTokenizer pathTokens = new StringTokenizer(p, "/"); for (StringTokenizer rootTokens = new StringTokenizer(root.toUri().getPath(), "/"); rootTokens .hasMoreTokens();) { if (!rootTokens.nextToken().equals(pathTokens.nextToken())) { return null; } } StringBuilder sb = new StringBuilder(); for (; pathTokens.hasMoreTokens();) { sb.append(pathTokens.nextToken()); if (pathTokens.hasMoreTokens()) { sb.append(Path.SEPARATOR); } } return sb.length() == 0 ? "." : sb.toString(); } /** * Calculate how many maps to run. * Number of maps is bounded by a minimum of the cumulative size of the * copy / (distcp.bytes.per.map, default BYTES_PER_MAP or -m on the * command line) and at most (distcp.max.map.tasks, default * MAX_MAPS_PER_NODE * nodes in the cluster). * @param totalBytes Count of total bytes for job * @param job The job to configure * @return Count of maps to run. */ private static void setMapCount(long totalBytes, JobConf job) throws IOException { int numMaps = (int) (totalBytes / job.getLong(BYTES_PER_MAP_LABEL, BYTES_PER_MAP)); numMaps = Math.min(numMaps, job.getInt(MAX_MAPS_LABEL, MAX_MAPS_PER_NODE * new JobClient(job).getClusterStatus().getTaskTrackers())); job.setNumMapTasks(Math.max(numMaps, 1)); } /** Fully delete dir */ static void fullyDelete(String dir, Configuration conf) throws IOException { if (dir != null) { Path tmp = new Path(dir); tmp.getFileSystem(conf).delete(tmp, true); } } //Job configuration private static JobConf createJobConf(Configuration conf) { JobConf jobconf = new JobConf(conf, DistCp.class); jobconf.setJobName(NAME); // turn off speculative execution, because DFS doesn't handle // multiple writers to the same file. jobconf.setMapSpeculativeExecution(false); jobconf.setInputFormat(CopyInputFormat.class); jobconf.setOutputKeyClass(Text.class); jobconf.setOutputValueClass(Text.class); jobconf.setMapperClass(CopyFilesMapper.class); jobconf.setNumReduceTasks(0); return jobconf; } private static final Random RANDOM = new Random(); public static String getRandomId() { return Integer.toString(RANDOM.nextInt(Integer.MAX_VALUE), 36); } /** * Initialize DFSCopyFileMapper specific job-configuration. * @param conf : The dfs/mapred configuration. * @param jobConf : The handle to the jobConf object to be initialized. * @param args Arguments */ private static void setup(Configuration conf, JobConf jobConf, final Arguments args) throws IOException { jobConf.set(DST_DIR_LABEL, args.dst.toUri().toString()); //set boolean values final boolean update = args.flags.contains(Options.UPDATE); final boolean overwrite = !update && args.flags.contains(Options.OVERWRITE); jobConf.setBoolean(Options.UPDATE.propertyname, update); jobConf.setBoolean(Options.OVERWRITE.propertyname, overwrite); jobConf.setBoolean(Options.IGNORE_READ_FAILURES.propertyname, args.flags.contains(Options.IGNORE_READ_FAILURES)); jobConf.setBoolean(Options.PRESERVE_STATUS.propertyname, args.flags.contains(Options.PRESERVE_STATUS)); final String randomId = getRandomId(); JobClient jClient = new JobClient(jobConf); Path jobDirectory = new Path(jClient.getSystemDir(), NAME + "_" + randomId); jobConf.set(JOB_DIR_LABEL, jobDirectory.toString()); FileSystem dstfs = args.dst.getFileSystem(conf); boolean dstExists = dstfs.exists(args.dst); boolean dstIsDir = false; if (dstExists) { dstIsDir = dstfs.getFileStatus(args.dst).isDir(); } // default logPath Path logPath = args.log; if (logPath == null) { String filename = "_distcp_logs_" + randomId; if (!dstExists || !dstIsDir) { Path parent = args.dst.getParent(); if (!dstfs.exists(parent)) { dstfs.mkdirs(parent); } logPath = new Path(parent, filename); } else { logPath = new Path(args.dst, filename); } } FileOutputFormat.setOutputPath(jobConf, logPath); // create src list, dst list FileSystem jobfs = jobDirectory.getFileSystem(jobConf); Path srcfilelist = new Path(jobDirectory, "_distcp_src_files"); jobConf.set(SRC_LIST_LABEL, srcfilelist.toString()); SequenceFile.Writer src_writer = SequenceFile.createWriter(jobfs, jobConf, srcfilelist, LongWritable.class, FilePair.class, SequenceFile.CompressionType.NONE); Path dstfilelist = new Path(jobDirectory, "_distcp_dst_files"); SequenceFile.Writer dst_writer = SequenceFile.createWriter(jobfs, jobConf, dstfilelist, Text.class, Text.class, SequenceFile.CompressionType.NONE); Path dstdirlist = new Path(jobDirectory, "_distcp_dst_dirs"); jobConf.set(DST_DIR_LIST_LABEL, dstdirlist.toString()); SequenceFile.Writer dir_writer = SequenceFile.createWriter(jobfs, jobConf, dstdirlist, Text.class, FilePair.class, SequenceFile.CompressionType.NONE); // handle the case where the destination directory doesn't exist // and we've only a single src directory OR we're updating/overwriting // the contents of the destination directory. final boolean special = (args.srcs.size() == 1 && !dstExists) || update || overwrite; int srcCount = 0, cnsyncf = 0, dirsyn = 0; long fileCount = 0L, byteCount = 0L, cbsyncs = 0L; try { for (Iterator<Path> srcItr = args.srcs.iterator(); srcItr.hasNext();) { final Path src = srcItr.next(); FileSystem srcfs = src.getFileSystem(conf); FileStatus srcfilestat = srcfs.getFileStatus(src); Path root = special && srcfilestat.isDir() ? src : src.getParent(); if (srcfilestat.isDir()) { ++srcCount; } Stack<FileStatus> pathstack = new Stack<FileStatus>(); for (pathstack.push(srcfilestat); !pathstack.empty();) { FileStatus cur = pathstack.pop(); FileStatus[] children = srcfs.listStatus(cur.getPath()); for (int i = 0; i < children.length; i++) { boolean skipfile = false; final FileStatus child = children[i]; final String dst = makeRelative(root, child.getPath()); ++srcCount; if (child.isDir()) { pathstack.push(child); } else { //skip file if the src and the dst files are the same. skipfile = update && sameFile(srcfs, child, dstfs, new Path(args.dst, dst)); //skip file if it exceed file limit or size limit skipfile |= fileCount == args.filelimit || byteCount + child.getLen() > args.sizelimit; if (!skipfile) { ++fileCount; byteCount += child.getLen(); if (LOG.isTraceEnabled()) { LOG.trace("adding file " + child.getPath()); } ++cnsyncf; cbsyncs += child.getLen(); if (cnsyncf > SYNC_FILE_MAX || cbsyncs > BYTES_PER_MAP) { src_writer.sync(); dst_writer.sync(); cnsyncf = 0; cbsyncs = 0L; } } } if (!skipfile) { src_writer.append(new LongWritable(child.isDir() ? 0 : child.getLen()), new FilePair(child, dst)); } dst_writer.append(new Text(dst), new Text(child.getPath().toString())); } if (cur.isDir()) { String dst = makeRelative(root, cur.getPath()); dir_writer.append(new Text(dst), new FilePair(cur, dst)); if (++dirsyn > SYNC_FILE_MAX) { dirsyn = 0; dir_writer.sync(); } } } } } finally { checkAndClose(src_writer); checkAndClose(dst_writer); checkAndClose(dir_writer); } FileStatus dststatus = null; try { dststatus = dstfs.getFileStatus(args.dst); } catch (FileNotFoundException fnfe) { LOG.info(args.dst + " does not exist."); } // create dest path dir if copying > 1 file if (dststatus == null) { if (srcCount > 1 && !dstfs.mkdirs(args.dst)) { throw new IOException("Failed to create" + args.dst); } } final Path sorted = new Path(jobDirectory, "_distcp_sorted"); checkDuplication(jobfs, dstfilelist, sorted, conf); if (dststatus != null && args.flags.contains(Options.DELETE)) { deleteNonexisting(dstfs, dststatus, sorted, jobfs, jobDirectory, jobConf, conf); } Path tmpDir = new Path( (dstExists && !dstIsDir) || (!dstExists && srcCount == 1) ? args.dst.getParent() : args.dst, "_distcp_tmp_" + randomId); jobConf.set(TMP_DIR_LABEL, tmpDir.toUri().toString()); LOG.info("srcCount=" + srcCount); jobConf.setInt(SRC_COUNT_LABEL, srcCount); jobConf.setLong(TOTAL_SIZE_LABEL, byteCount); setMapCount(byteCount, jobConf); } /** * Check whether the contents of src and dst are the same. * * Return false if dstpath does not exist * * If the files have different sizes, return false. * * If the files have the same sizes, the file checksums will be compared. * * When file checksum is not supported in any of file systems, * two files are considered as the same if they have the same size. */ static private boolean sameFile(FileSystem srcfs, FileStatus srcstatus, FileSystem dstfs, Path dstpath) throws IOException { FileStatus dststatus; try { dststatus = dstfs.getFileStatus(dstpath); } catch (FileNotFoundException fnfe) { return false; } //same length? if (srcstatus.getLen() != dststatus.getLen()) { return false; } //compare checksums try { final FileChecksum srccs = srcfs.getFileChecksum(srcstatus.getPath()); final FileChecksum dstcs = dstfs.getFileChecksum(dststatus.getPath()); //return true if checksum is not supported //(i.e. some of the checksums is null) return srccs == null || dstcs == null || srccs.equals(dstcs); } catch (FileNotFoundException fnfe) { return false; } } /** Delete the dst files/dirs which do not exist in src */ static private void deleteNonexisting(FileSystem dstfs, FileStatus dstroot, Path dstsorted, FileSystem jobfs, Path jobdir, JobConf jobconf, Configuration conf) throws IOException { if (!dstroot.isDir()) { throw new IOException("dst must be a directory when option " + Options.DELETE.cmd + " is set, but dst (= " + dstroot.getPath() + ") is not a directory."); } //write dst lsr results final Path dstlsr = new Path(jobdir, "_distcp_dst_lsr"); final SequenceFile.Writer writer = SequenceFile.createWriter(jobfs, jobconf, dstlsr, Text.class, FileStatus.class, SequenceFile.CompressionType.NONE); try { //do lsr to get all file statuses in dstroot final Stack<FileStatus> lsrstack = new Stack<FileStatus>(); for (lsrstack.push(dstroot); !lsrstack.isEmpty();) { final FileStatus status = lsrstack.pop(); if (status.isDir()) { for (FileStatus child : dstfs.listStatus(status.getPath())) { String relative = makeRelative(dstroot.getPath(), child.getPath()); writer.append(new Text(relative), child); lsrstack.push(child); } } } } finally { checkAndClose(writer); } //sort lsr results final Path sortedlsr = new Path(jobdir, "_distcp_dst_lsr_sorted"); SequenceFile.Sorter sorter = new SequenceFile.Sorter(jobfs, new Text.Comparator(), Text.class, FileStatus.class, jobconf); sorter.sort(dstlsr, sortedlsr); //compare lsr list and dst list SequenceFile.Reader lsrin = null; SequenceFile.Reader dstin = null; try { lsrin = new SequenceFile.Reader(jobfs, sortedlsr, jobconf); dstin = new SequenceFile.Reader(jobfs, dstsorted, jobconf); //compare sorted lsr list and sorted dst list final Text lsrpath = new Text(); final FileStatus lsrstatus = new FileStatus(); final Text dstpath = new Text(); final Text dstfrom = new Text(); final FsShell shell = new FsShell(conf); final String[] shellargs = { "-rmr", null }; boolean hasnext = dstin.next(dstpath, dstfrom); for (; lsrin.next(lsrpath, lsrstatus);) { int dst_cmp_lsr = dstpath.compareTo(lsrpath); for (; hasnext && dst_cmp_lsr < 0;) { hasnext = dstin.next(dstpath, dstfrom); dst_cmp_lsr = dstpath.compareTo(lsrpath); } if (dst_cmp_lsr == 0) { //lsrpath exists in dst, skip it hasnext = dstin.next(dstpath, dstfrom); } else { //lsrpath does not exist, delete it String s = new Path(dstroot.getPath(), lsrpath.toString()).toString(); if (shellargs[1] == null || !isAncestorPath(shellargs[1], s)) { shellargs[1] = s; int r = 0; try { r = shell.run(shellargs); } catch (Exception e) { throw new IOException("Exception from shell.", e); } if (r != 0) { throw new IOException( "\"" + shellargs[0] + " " + shellargs[1] + "\" returns non-zero value " + r); } } } } } finally { checkAndClose(lsrin); checkAndClose(dstin); } } //is x an ancestor path of y? static private boolean isAncestorPath(String x, String y) { if (!y.startsWith(x)) { return false; } final int len = x.length(); return y.length() == len || y.charAt(len) == Path.SEPARATOR_CHAR; } /** Check whether the file list have duplication. */ static private void checkDuplication(FileSystem fs, Path file, Path sorted, Configuration conf) throws IOException { SequenceFile.Reader in = null; try { SequenceFile.Sorter sorter = new SequenceFile.Sorter(fs, new Text.Comparator(), Text.class, Text.class, conf); sorter.sort(file, sorted); in = new SequenceFile.Reader(fs, sorted, conf); Text prevdst = null, curdst = new Text(); Text prevsrc = null, cursrc = new Text(); for (; in.next(curdst, cursrc);) { if (prevdst != null && curdst.equals(prevdst)) { throw new DuplicationException( "Invalid input, there are duplicated files in the sources: " + prevsrc + ", " + cursrc); } prevdst = curdst; curdst = new Text(); prevsrc = cursrc; cursrc = new Text(); } } finally { checkAndClose(in); } } static boolean checkAndClose(java.io.Closeable io) { if (io != null) { try { io.close(); } catch (IOException ioe) { LOG.warn(StringUtils.stringifyException(ioe)); return false; } } return true; } /** An exception class for duplicated source files. */ public static class DuplicationException extends IOException { private static final long serialVersionUID = 1L; /** Error code for this exception */ public static final int ERROR_CODE = -2; DuplicationException(String message) { super(message); } } }