| /** |
| * 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.mapred; |
| |
| import java.io.IOException; |
| import java.util.ArrayList; |
| import java.util.Collections; |
| import java.util.Comparator; |
| import java.util.HashSet; |
| import java.util.IdentityHashMap; |
| import java.util.LinkedList; |
| import java.util.List; |
| import java.util.Map; |
| import java.util.Set; |
| |
| import org.apache.commons.logging.Log; |
| import org.apache.commons.logging.LogFactory; |
| import org.apache.hadoop.fs.BlockLocation; |
| import org.apache.hadoop.fs.FileStatus; |
| import org.apache.hadoop.fs.FileSystem; |
| import org.apache.hadoop.fs.Path; |
| import org.apache.hadoop.fs.PathFilter; |
| import org.apache.hadoop.mapreduce.security.TokenCache; |
| import org.apache.hadoop.net.NetworkTopology; |
| import org.apache.hadoop.net.Node; |
| import org.apache.hadoop.net.NodeBase; |
| import org.apache.hadoop.util.ReflectionUtils; |
| import org.apache.hadoop.util.StringUtils; |
| |
| /** |
| * A base class for file-based {@link InputFormat}. |
| * |
| * <p><code>FileInputFormat</code> is the base class for all file-based |
| * <code>InputFormat</code>s. This provides a generic implementation of |
| * {@link #getSplits(JobConf, int)}. |
| * Subclasses of <code>FileInputFormat</code> can also override the |
| * {@link #isSplitable(FileSystem, Path)} method to ensure input-files are |
| * not split-up and are processed as a whole by {@link Mapper}s. |
| */ |
| public abstract class FileInputFormat<K, V> implements InputFormat<K, V> { |
| |
| public static final Log LOG = |
| LogFactory.getLog(FileInputFormat.class); |
| public static enum Counter { |
| BYTES_READ |
| } |
| |
| private static final double SPLIT_SLOP = 1.1; // 10% slop |
| |
| private long minSplitSize = 1; |
| private static final PathFilter hiddenFileFilter = new PathFilter(){ |
| public boolean accept(Path p){ |
| String name = p.getName(); |
| return !name.startsWith("_") && !name.startsWith("."); |
| } |
| }; |
| |
| static final String NUM_INPUT_FILES = "mapreduce.input.num.files"; |
| |
| protected void setMinSplitSize(long minSplitSize) { |
| this.minSplitSize = minSplitSize; |
| } |
| |
| /** |
| * Proxy PathFilter that accepts a path only if all filters given in the |
| * constructor do. Used by the listPaths() to apply the built-in |
| * hiddenFileFilter together with a user provided one (if any). |
| */ |
| private static class MultiPathFilter implements PathFilter { |
| private List<PathFilter> filters; |
| |
| public MultiPathFilter(List<PathFilter> filters) { |
| this.filters = filters; |
| } |
| |
| public boolean accept(Path path) { |
| for (PathFilter filter : filters) { |
| if (!filter.accept(path)) { |
| return false; |
| } |
| } |
| return true; |
| } |
| } |
| |
| /** |
| * Is the given filename splitable? Usually, true, but if the file is |
| * stream compressed, it will not be. |
| * |
| * <code>FileInputFormat</code> implementations can override this and return |
| * <code>false</code> to ensure that individual input files are never split-up |
| * so that {@link Mapper}s process entire files. |
| * |
| * @param fs the file system that the file is on |
| * @param filename the file name to check |
| * @return is this file splitable? |
| */ |
| protected boolean isSplitable(FileSystem fs, Path filename) { |
| return true; |
| } |
| |
| public abstract RecordReader<K, V> getRecordReader(InputSplit split, |
| JobConf job, |
| Reporter reporter) |
| throws IOException; |
| |
| /** |
| * Set a PathFilter to be applied to the input paths for the map-reduce job. |
| * |
| * @param filter the PathFilter class use for filtering the input paths. |
| */ |
| public static void setInputPathFilter(JobConf conf, |
| Class<? extends PathFilter> filter) { |
| conf.setClass("mapred.input.pathFilter.class", filter, PathFilter.class); |
| } |
| |
| /** |
| * Get a PathFilter instance of the filter set for the input paths. |
| * |
| * @return the PathFilter instance set for the job, NULL if none has been set. |
| */ |
| public static PathFilter getInputPathFilter(JobConf conf) { |
| Class<? extends PathFilter> filterClass = conf.getClass( |
| "mapred.input.pathFilter.class", null, PathFilter.class); |
| return (filterClass != null) ? |
| ReflectionUtils.newInstance(filterClass, conf) : null; |
| } |
| |
| /** List input directories. |
| * Subclasses may override to, e.g., select only files matching a regular |
| * expression. |
| * |
| * @param job the job to list input paths for |
| * @return array of FileStatus objects |
| * @throws IOException if zero items. |
| */ |
| protected FileStatus[] listStatus(JobConf job) throws IOException { |
| Path[] dirs = getInputPaths(job); |
| if (dirs.length == 0) { |
| throw new IOException("No input paths specified in job"); |
| } |
| |
| // get tokens for all the required FileSystems.. |
| TokenCache.obtainTokensForNamenodes(job.getCredentials(), dirs, job); |
| |
| List<FileStatus> result = new ArrayList<FileStatus>(); |
| List<IOException> errors = new ArrayList<IOException>(); |
| |
| // creates a MultiPathFilter with the hiddenFileFilter and the |
| // user provided one (if any). |
| List<PathFilter> filters = new ArrayList<PathFilter>(); |
| filters.add(hiddenFileFilter); |
| PathFilter jobFilter = getInputPathFilter(job); |
| if (jobFilter != null) { |
| filters.add(jobFilter); |
| } |
| PathFilter inputFilter = new MultiPathFilter(filters); |
| |
| for (Path p: dirs) { |
| FileSystem fs = p.getFileSystem(job); |
| FileStatus[] matches = fs.globStatus(p, inputFilter); |
| if (matches == null) { |
| errors.add(new IOException("Input path does not exist: " + p)); |
| } else if (matches.length == 0) { |
| errors.add(new IOException("Input Pattern " + p + " matches 0 files")); |
| } else { |
| for (FileStatus globStat: matches) { |
| if (globStat.isDir()) { |
| for(FileStatus stat: fs.listStatus(globStat.getPath(), |
| inputFilter)) { |
| result.add(stat); |
| } |
| } else { |
| result.add(globStat); |
| } |
| } |
| } |
| } |
| |
| if (!errors.isEmpty()) { |
| throw new InvalidInputException(errors); |
| } |
| LOG.info("Total input paths to process : " + result.size()); |
| return result.toArray(new FileStatus[result.size()]); |
| } |
| |
| /** Splits files returned by {@link #listStatus(JobConf)} when |
| * they're too big.*/ |
| @SuppressWarnings("deprecation") |
| public InputSplit[] getSplits(JobConf job, int numSplits) |
| throws IOException { |
| FileStatus[] files = listStatus(job); |
| |
| // Save the number of input files in the job-conf |
| job.setLong(NUM_INPUT_FILES, files.length); |
| long totalSize = 0; // compute total size |
| for (FileStatus file: files) { // check we have valid files |
| if (file.isDir()) { |
| throw new IOException("Not a file: "+ file.getPath()); |
| } |
| totalSize += file.getLen(); |
| } |
| |
| long goalSize = totalSize / (numSplits == 0 ? 1 : numSplits); |
| long minSize = Math.max(job.getLong("mapred.min.split.size", 1), |
| minSplitSize); |
| |
| // generate splits |
| ArrayList<FileSplit> splits = new ArrayList<FileSplit>(numSplits); |
| NetworkTopology clusterMap = new NetworkTopology(); |
| for (FileStatus file: files) { |
| Path path = file.getPath(); |
| FileSystem fs = path.getFileSystem(job); |
| long length = file.getLen(); |
| BlockLocation[] blkLocations = fs.getFileBlockLocations(file, 0, length); |
| if ((length != 0) && isSplitable(fs, path)) { |
| long blockSize = file.getBlockSize(); |
| long splitSize = computeSplitSize(goalSize, minSize, blockSize); |
| |
| long bytesRemaining = length; |
| while (((double) bytesRemaining)/splitSize > SPLIT_SLOP) { |
| String[] splitHosts = getSplitHosts(blkLocations, |
| length-bytesRemaining, splitSize, clusterMap); |
| splits.add(new FileSplit(path, length-bytesRemaining, splitSize, |
| splitHosts)); |
| bytesRemaining -= splitSize; |
| } |
| |
| if (bytesRemaining != 0) { |
| splits.add(new FileSplit(path, length-bytesRemaining, bytesRemaining, |
| blkLocations[blkLocations.length-1].getHosts())); |
| } |
| } else if (length != 0) { |
| String[] splitHosts = getSplitHosts(blkLocations,0,length,clusterMap); |
| splits.add(new FileSplit(path, 0, length, splitHosts)); |
| } else { |
| //Create empty hosts array for zero length files |
| splits.add(new FileSplit(path, 0, length, new String[0])); |
| } |
| } |
| LOG.debug("Total # of splits: " + splits.size()); |
| return splits.toArray(new FileSplit[splits.size()]); |
| } |
| |
| protected long computeSplitSize(long goalSize, long minSize, |
| long blockSize) { |
| return Math.max(minSize, Math.min(goalSize, blockSize)); |
| } |
| |
| protected int getBlockIndex(BlockLocation[] blkLocations, |
| long offset) { |
| for (int i = 0 ; i < blkLocations.length; i++) { |
| // is the offset inside this block? |
| if ((blkLocations[i].getOffset() <= offset) && |
| (offset < blkLocations[i].getOffset() + blkLocations[i].getLength())){ |
| return i; |
| } |
| } |
| BlockLocation last = blkLocations[blkLocations.length -1]; |
| long fileLength = last.getOffset() + last.getLength() -1; |
| throw new IllegalArgumentException("Offset " + offset + |
| " is outside of file (0.." + |
| fileLength + ")"); |
| } |
| |
| /** |
| * Sets the given comma separated paths as the list of inputs |
| * for the map-reduce job. |
| * |
| * @param conf Configuration of the job |
| * @param commaSeparatedPaths Comma separated paths to be set as |
| * the list of inputs for the map-reduce job. |
| */ |
| public static void setInputPaths(JobConf conf, String commaSeparatedPaths) { |
| setInputPaths(conf, StringUtils.stringToPath( |
| getPathStrings(commaSeparatedPaths))); |
| } |
| |
| /** |
| * Add the given comma separated paths to the list of inputs for |
| * the map-reduce job. |
| * |
| * @param conf The configuration of the job |
| * @param commaSeparatedPaths Comma separated paths to be added to |
| * the list of inputs for the map-reduce job. |
| */ |
| public static void addInputPaths(JobConf conf, String commaSeparatedPaths) { |
| for (String str : getPathStrings(commaSeparatedPaths)) { |
| addInputPath(conf, new Path(str)); |
| } |
| } |
| |
| /** |
| * Set the array of {@link Path}s as the list of inputs |
| * for the map-reduce job. |
| * |
| * @param conf Configuration of the job. |
| * @param inputPaths the {@link Path}s of the input directories/files |
| * for the map-reduce job. |
| */ |
| public static void setInputPaths(JobConf conf, Path... inputPaths) { |
| Path path = new Path(conf.getWorkingDirectory(), inputPaths[0]); |
| StringBuffer str = new StringBuffer(StringUtils.escapeString(path.toString())); |
| for(int i = 1; i < inputPaths.length;i++) { |
| str.append(StringUtils.COMMA_STR); |
| path = new Path(conf.getWorkingDirectory(), inputPaths[i]); |
| str.append(StringUtils.escapeString(path.toString())); |
| } |
| conf.set("mapred.input.dir", str.toString()); |
| } |
| |
| /** |
| * Add a {@link Path} to the list of inputs for the map-reduce job. |
| * |
| * @param conf The configuration of the job |
| * @param path {@link Path} to be added to the list of inputs for |
| * the map-reduce job. |
| */ |
| public static void addInputPath(JobConf conf, Path path ) { |
| path = new Path(conf.getWorkingDirectory(), path); |
| String dirStr = StringUtils.escapeString(path.toString()); |
| String dirs = conf.get("mapred.input.dir"); |
| conf.set("mapred.input.dir", dirs == null ? dirStr : |
| dirs + StringUtils.COMMA_STR + dirStr); |
| } |
| |
| // This method escapes commas in the glob pattern of the given paths. |
| private static String[] getPathStrings(String commaSeparatedPaths) { |
| int length = commaSeparatedPaths.length(); |
| int curlyOpen = 0; |
| int pathStart = 0; |
| boolean globPattern = false; |
| List<String> pathStrings = new ArrayList<String>(); |
| |
| for (int i=0; i<length; i++) { |
| char ch = commaSeparatedPaths.charAt(i); |
| switch(ch) { |
| case '{' : { |
| curlyOpen++; |
| if (!globPattern) { |
| globPattern = true; |
| } |
| break; |
| } |
| case '}' : { |
| curlyOpen--; |
| if (curlyOpen == 0 && globPattern) { |
| globPattern = false; |
| } |
| break; |
| } |
| case ',' : { |
| if (!globPattern) { |
| pathStrings.add(commaSeparatedPaths.substring(pathStart, i)); |
| pathStart = i + 1 ; |
| } |
| break; |
| } |
| } |
| } |
| pathStrings.add(commaSeparatedPaths.substring(pathStart, length)); |
| |
| return pathStrings.toArray(new String[0]); |
| } |
| |
| /** |
| * Get the list of input {@link Path}s for the map-reduce job. |
| * |
| * @param conf The configuration of the job |
| * @return the list of input {@link Path}s for the map-reduce job. |
| */ |
| public static Path[] getInputPaths(JobConf conf) { |
| String dirs = conf.get("mapred.input.dir", ""); |
| String [] list = StringUtils.split(dirs); |
| Path[] result = new Path[list.length]; |
| for (int i = 0; i < list.length; i++) { |
| result[i] = new Path(StringUtils.unEscapeString(list[i])); |
| } |
| return result; |
| } |
| |
| |
| private void sortInDescendingOrder(List<NodeInfo> mylist) { |
| Collections.sort(mylist, new Comparator<NodeInfo> () { |
| public int compare(NodeInfo obj1, NodeInfo obj2) { |
| |
| if (obj1 == null || obj2 == null) |
| return -1; |
| |
| if (obj1.getValue() == obj2.getValue()) { |
| return 0; |
| } |
| else { |
| return ((obj1.getValue() < obj2.getValue()) ? 1 : -1); |
| } |
| } |
| } |
| ); |
| } |
| |
| /** |
| * This function identifies and returns the hosts that contribute |
| * most for a given split. For calculating the contribution, rack |
| * locality is treated on par with host locality, so hosts from racks |
| * that contribute the most are preferred over hosts on racks that |
| * contribute less |
| * @param blkLocations The list of block locations |
| * @param offset |
| * @param splitSize |
| * @return array of hosts that contribute most to this split |
| * @throws IOException |
| */ |
| protected String[] getSplitHosts(BlockLocation[] blkLocations, |
| long offset, long splitSize, NetworkTopology clusterMap) |
| throws IOException { |
| |
| int startIndex = getBlockIndex(blkLocations, offset); |
| |
| long bytesInThisBlock = blkLocations[startIndex].getOffset() + |
| blkLocations[startIndex].getLength() - offset; |
| |
| //If this is the only block, just return |
| if (bytesInThisBlock >= splitSize) { |
| return blkLocations[startIndex].getHosts(); |
| } |
| |
| long bytesInFirstBlock = bytesInThisBlock; |
| int index = startIndex + 1; |
| splitSize -= bytesInThisBlock; |
| |
| while (splitSize > 0) { |
| bytesInThisBlock = |
| Math.min(splitSize, blkLocations[index++].getLength()); |
| splitSize -= bytesInThisBlock; |
| } |
| |
| long bytesInLastBlock = bytesInThisBlock; |
| int endIndex = index - 1; |
| |
| Map <Node,NodeInfo> hostsMap = new IdentityHashMap<Node,NodeInfo>(); |
| Map <Node,NodeInfo> racksMap = new IdentityHashMap<Node,NodeInfo>(); |
| String [] allTopos = new String[0]; |
| |
| // Build the hierarchy and aggregate the contribution of |
| // bytes at each level. See TestGetSplitHosts.java |
| |
| for (index = startIndex; index <= endIndex; index++) { |
| |
| // Establish the bytes in this block |
| if (index == startIndex) { |
| bytesInThisBlock = bytesInFirstBlock; |
| } |
| else if (index == endIndex) { |
| bytesInThisBlock = bytesInLastBlock; |
| } |
| else { |
| bytesInThisBlock = blkLocations[index].getLength(); |
| } |
| |
| allTopos = blkLocations[index].getTopologyPaths(); |
| |
| // If no topology information is available, just |
| // prefix a fakeRack |
| if (allTopos.length == 0) { |
| allTopos = fakeRacks(blkLocations, index); |
| } |
| |
| // NOTE: This code currently works only for one level of |
| // hierarchy (rack/host). However, it is relatively easy |
| // to extend this to support aggregation at different |
| // levels |
| |
| for (String topo: allTopos) { |
| |
| Node node, parentNode; |
| NodeInfo nodeInfo, parentNodeInfo; |
| |
| node = clusterMap.getNode(topo); |
| |
| if (node == null) { |
| node = new NodeBase(topo); |
| clusterMap.add(node); |
| } |
| |
| nodeInfo = hostsMap.get(node); |
| |
| if (nodeInfo == null) { |
| nodeInfo = new NodeInfo(node); |
| hostsMap.put(node,nodeInfo); |
| parentNode = node.getParent(); |
| parentNodeInfo = racksMap.get(parentNode); |
| if (parentNodeInfo == null) { |
| parentNodeInfo = new NodeInfo(parentNode); |
| racksMap.put(parentNode,parentNodeInfo); |
| } |
| parentNodeInfo.addLeaf(nodeInfo); |
| } |
| else { |
| nodeInfo = hostsMap.get(node); |
| parentNode = node.getParent(); |
| parentNodeInfo = racksMap.get(parentNode); |
| } |
| |
| nodeInfo.addValue(index, bytesInThisBlock); |
| parentNodeInfo.addValue(index, bytesInThisBlock); |
| |
| } // for all topos |
| |
| } // for all indices |
| |
| return identifyHosts(allTopos.length, racksMap); |
| } |
| |
| private String[] identifyHosts(int replicationFactor, |
| Map<Node,NodeInfo> racksMap) { |
| |
| String [] retVal = new String[replicationFactor]; |
| |
| List <NodeInfo> rackList = new LinkedList<NodeInfo>(); |
| |
| rackList.addAll(racksMap.values()); |
| |
| // Sort the racks based on their contribution to this split |
| sortInDescendingOrder(rackList); |
| |
| boolean done = false; |
| int index = 0; |
| |
| // Get the host list for all our aggregated items, sort |
| // them and return the top entries |
| for (NodeInfo ni: rackList) { |
| |
| Set<NodeInfo> hostSet = ni.getLeaves(); |
| |
| List<NodeInfo>hostList = new LinkedList<NodeInfo>(); |
| hostList.addAll(hostSet); |
| |
| // Sort the hosts in this rack based on their contribution |
| sortInDescendingOrder(hostList); |
| |
| for (NodeInfo host: hostList) { |
| // Strip out the port number from the host name |
| retVal[index++] = host.node.getName().split(":")[0]; |
| if (index == replicationFactor) { |
| done = true; |
| break; |
| } |
| } |
| |
| if (done == true) { |
| break; |
| } |
| } |
| return retVal; |
| } |
| |
| private String[] fakeRacks(BlockLocation[] blkLocations, int index) |
| throws IOException { |
| String[] allHosts = blkLocations[index].getHosts(); |
| String[] allTopos = new String[allHosts.length]; |
| for (int i = 0; i < allHosts.length; i++) { |
| allTopos[i] = NetworkTopology.DEFAULT_RACK + "/" + allHosts[i]; |
| } |
| return allTopos; |
| } |
| |
| |
| private static class NodeInfo { |
| final Node node; |
| final Set<Integer> blockIds; |
| final Set<NodeInfo> leaves; |
| |
| private long value; |
| |
| NodeInfo(Node node) { |
| this.node = node; |
| blockIds = new HashSet<Integer>(); |
| leaves = new HashSet<NodeInfo>(); |
| } |
| |
| long getValue() {return value;} |
| |
| void addValue(int blockIndex, long value) { |
| if (blockIds.add(blockIndex) == true) { |
| this.value += value; |
| } |
| } |
| |
| Set<NodeInfo> getLeaves() { return leaves;} |
| |
| void addLeaf(NodeInfo nodeInfo) { |
| leaves.add(nodeInfo); |
| } |
| } |
| } |