Example usage for org.apache.hadoop.mapred JobConf setInputFormat

List of usage examples for org.apache.hadoop.mapred JobConf setInputFormat

Introduction

In this page you can find the example usage for org.apache.hadoop.mapred JobConf setInputFormat.

Prototype

public void setInputFormat(Class<? extends InputFormat> theClass) 

Source Link

Document

Set the InputFormat implementation for the map-reduce job.

Usage

From source file:edu.umd.cloud9.webgraph.driver.BuildIndexableAnchorCollection.java

License:Apache License

/**
 * Runs this tool./*  w w w  .jav  a  2 s.c o m*/
 */
public int run(String[] args) throws Exception {
    if (args.length < 5) {
        printUsage();
        return -1;
    }

    JobConf conf = new JobConf(getConf());
    FileSystem fs = FileSystem.get(conf);

    String collectionPath = DriverUtil.argValue(args, DriverUtil.CL_INPUT);
    String outputPath = DriverUtil.argValue(args, DriverUtil.CL_OUTPUT);
    String docnoMappingClass = DriverUtil.argValue(args, DriverUtil.CL_DOCNO_MAPPING_CLASS);
    String docnoMapping = DriverUtil.argValue(args, DriverUtil.CL_DOCNO_MAPPING);
    int numReducers = Integer.parseInt(DriverUtil.argValue(args, DriverUtil.CL_NUMBER_OF_REDUCERS));
    if (DriverUtil.argExists(args, DriverUtil.CL_MAX_LENGTH)) {
        conf.setInt("Cloud9.maxContentLength",
                Integer.parseInt(DriverUtil.argValue(args, DriverUtil.CL_MAX_LENGTH)));
    }
    conf.set("Cloud9.DocnoMappingClass", docnoMappingClass);

    LOG.info("Tool name: BuildAnchorTextForwardIndex");
    LOG.info(" - collection path: " + collectionPath);
    LOG.info(" - output path: " + outputPath);
    LOG.info(" - docno-mapping class: " + docnoMappingClass);
    LOG.info(" - docno-mapping file: " + docnoMapping);
    if (args.length == 6) {
        LOG.info(" - maximum content length: " + conf.getInt("Cloud9.maxContentLength", 0));
    }

    conf.set("mapred.child.java.opts", "-Xmx2048m");
    conf.setJobName("BuildIndexableAnchorCollection");
    conf.setJarByClass(BuildIndexableAnchorCollection.class);

    conf.setNumMapTasks(100);
    conf.setNumReduceTasks(numReducers);
    DistributedCache.addCacheFile(new URI(docnoMapping), conf);

    conf.setInputFormat(SequenceFileInputFormat.class);
    conf.setOutputFormat(SequenceFileOutputFormat.class);
    SequenceFileOutputFormat.setCompressOutput(conf, true);
    SequenceFileOutputFormat.setOutputCompressionType(conf, SequenceFile.CompressionType.BLOCK);
    SequenceFileInputFormat.setInputPaths(conf, new Path(collectionPath));
    SequenceFileOutputFormat.setOutputPath(conf, new Path(outputPath));

    conf.setOutputKeyClass(IntWritable.class);
    conf.setOutputValueClass(IndexableAnchorText.class);

    conf.setMapperClass(MyMapper.class);
    conf.setReducerClass(IdentityReducer.class);

    // delete the output directory if it exists already
    fs.delete(new Path(outputPath), true);
    RunningJob job = JobClient.runJob(conf);

    return 0;
}

From source file:edu.umd.cloud9.webgraph.driver.ClueWebAnchorTextForwardIndexHttpServer.java

License:Apache License

public static void main(String[] args) throws Exception {
    Configuration conf = new Configuration();
    String[] otherArgs = new GenericOptionsParser(conf, args).getRemainingArgs();

    if (otherArgs.length != 3) {
        System.out.println("usage: [index-file] [docno-mapping-data-files] [clue-forward-index-root]");
        //[clue-forward-index-root: /shared/ClueWeb09/collection.compressed.block/
        System.exit(-1);//from   w  ww  .  ja  v  a 2  s .co m
    }

    String indexFile = otherArgs[0];
    String mappingFile = otherArgs[1];
    String clueIndexRoot = otherArgs[2].endsWith("/") ? otherArgs[2] : otherArgs[2] + "/";

    String cluewebForwardIndex = "";
    for (int i = 1; i < 10; i++)
        cluewebForwardIndex += clueIndexRoot + "findex.en.0" + i + ".dat" + SEPARATOR + " ";
    cluewebForwardIndex += clueIndexRoot + "findex.en.10.dat";

    LOG.info("Launching DocumentForwardIndexHttpServer");
    LOG.info(" - index file: " + indexFile);
    LOG.info(" - docno mapping data file: " + mappingFile);
    LOG.info(" - ClueWeb09 index root:" + clueIndexRoot);

    FileSystem fs = FileSystem.get(conf);

    Random rand = new Random();
    int r = rand.nextInt();

    // this tmp file as a rendezvous point
    Path tmpPath = new Path("/tmp/" + r);

    if (fs.exists(tmpPath)) {
        fs.delete(tmpPath, true);
    }

    JobConf job = new JobConf(conf, ClueWebAnchorTextForwardIndexHttpServer.class);

    job.setJobName("ForwardIndexServer:" + indexFile);

    job.set("mapred.child.java.opts", "-Xmx2048m");

    job.setNumMapTasks(1);
    job.setNumReduceTasks(0);

    job.setInputFormat(NullInputFormat.class);
    job.setOutputFormat(NullOutputFormat.class);
    job.setMapperClass(ServerMapper.class);

    job.set("IndexFile", indexFile);
    job.set("DocnoMappingDataFile", mappingFile);
    job.set("TmpPath", tmpPath.toString());
    job.set("ClueWebIndexFiles", cluewebForwardIndex);

    JobClient client = new JobClient(job);
    client.submitJob(job);

    LOG.info("Waiting for server to start up...");

    while (!fs.exists(tmpPath)) {
        Thread.sleep(50000);
        LOG.info("...");
    }

    FSDataInputStream in = fs.open(tmpPath);
    String host = in.readUTF();
    in.close();

    LOG.info("host: " + host);
    LOG.info("port: 8888");
}

From source file:edu.umd.cloud9.webgraph.driver.GenerateTabDelimitedWebGraph.java

License:Apache License

public int run(String[] args) throws Exception {
    if (args.length < 4) {
        printUsage();//from  ww  w.  j a v  a 2 s . c o  m
        return -1;
    }

    JobConf conf = new JobConf(getConf(), GenerateTabDelimitedWebGraph.class);
    FileSystem fs = FileSystem.get(conf);

    String inPath = DriverUtil.argValue(args, "-webgraph") + "/" + DriverUtil.OUTPUT_WEBGRAPH;
    String outPath = DriverUtil.argValue(args, "-output");

    Path inputPath = new Path(inPath);
    Path outputPath = new Path(outPath);

    if (fs.exists(outputPath)) {
        fs.delete(outputPath);
    }

    conf.setJobName("TabDelimWebGraph");
    conf.set("mapred.child.java.opts", "-Xmx2048m");
    conf.set("mapreduce.map.memory.mb", "2048");
    conf.set("mapreduce.map.java.opts", "-Xmx2048m");
    conf.set("mapreduce.reduce.memory.mb", "2048");
    conf.set("mapreduce.reduce.java.opts", "-Xmx2048m");
    conf.set("mapreduce.task.timeout", "60000000");

    conf.setNumMapTasks(1);
    conf.setNumReduceTasks(0);

    FileInputFormat.setInputPaths(conf, inputPath);
    FileOutputFormat.setOutputPath(conf, outputPath);

    conf.setInputFormat(SequenceFileInputFormat.class);
    conf.setOutputFormat(TextOutputFormat.class);
    conf.setOutputKeyClass(IntWritable.class);
    conf.setOutputValueClass(Text.class);
    conf.setMapperClass(MyMapper.class);

    JobClient.runJob(conf);
    return 0;
}

From source file:edu.umd.cloud9.webgraph.driver.SortWebGraph.java

License:Apache License

public int run(String[] args) throws Exception {
    if (args.length != 4) {
        printUsage();/*from   ww  w  .ja  v  a2 s.  c o  m*/
        return -1;
    }

    JobConf conf = new JobConf(getConf(), SortWebGraph.class);
    FileSystem fs = FileSystem.get(conf);

    String inputPath = args[0];
    String outputPath = args[1];
    int numberOfDocuments = Integer.parseInt(args[2]);
    int numMappers = 1;
    int numReducers = Integer.parseInt(args[3]);

    conf.setJobName("SortWebGraph");
    conf.set("mapred.child.java.opts", "-Xmx2048m");
    conf.setInt("mapred.task.timeout", 60000000);
    conf.set("mapreduce.map.memory.mb", "2048");
    conf.set("mapreduce.map.java.opts", "-Xmx2048m");
    conf.set("mapreduce.reduce.memory.mb", "2048");
    conf.set("mapreduce.reduce.java.opts", "-Xmx2048m");
    conf.set("mapreduce.task.timeout", "60000000");

    if (numberOfDocuments == 0) {
        numberOfDocuments = DEFAULT_NUMBER_OF_DOCUMENTS;
    }
    conf.setInt("Cloud9.NumberOfDocuments", numberOfDocuments);
    conf.setNumMapTasks(numMappers);
    conf.setNumReduceTasks(numReducers);
    conf.setMapperClass(IdentityMapper.class);
    conf.setPartitionerClass(Partition.class);
    conf.setReducerClass(IdentityReducer.class);
    conf.setOutputKeyClass(IntWritable.class);
    conf.setOutputValueClass(ArrayListWritable.class);
    conf.setMapOutputKeyClass(IntWritable.class);
    conf.setMapOutputValueClass(ArrayListWritable.class);
    conf.setInputFormat(SequenceFileInputFormat.class);
    conf.setOutputFormat(SequenceFileOutputFormat.class);
    SequenceFileOutputFormat.setCompressOutput(conf, true);
    SequenceFileOutputFormat.setOutputCompressionType(conf, SequenceFile.CompressionType.BLOCK);
    SequenceFileInputFormat.setInputPaths(conf, inputPath);
    FileOutputFormat.setOutputPath(conf, new Path(outputPath));

    LOG.info("SortAnchorText");
    LOG.info(" - input path: " + inputPath);
    LOG.info(" - output path: " + outputPath);
    LOG.info(" - number of documents: " + conf.getInt("Cloud9.NumberOfDocuments", DEFAULT_NUMBER_OF_DOCUMENTS));
    fs.delete(new Path(outputPath));
    JobClient.runJob(conf);
    return 0;
}

From source file:edu.umd.cloud9.webgraph.ExtractLinks.java

License:Apache License

public int runTool() throws Exception {

    JobConf conf = new JobConf(getConf(), ExtractLinks.class);
    FileSystem fs = FileSystem.get(conf);

    int numMappers = conf.getInt("Cloud9.Mappers", 1);
    int numReducers = conf.getInt("Cloud9.Reducers", 200);

    String inputPath = conf.get("Cloud9.InputPath");
    String outputPath = conf.get("Cloud9.OutputPath");
    String mappingFile = conf.get("Cloud9.DocnoMappingFile");

    if (!fs.exists(new Path(mappingFile)))
        throw new RuntimeException("Error: Docno mapping data file " + mappingFile + " doesn't exist!");

    DistributedCache.addCacheFile(new URI(mappingFile), conf);

    conf.setJobName("ExtractLinks");
    conf.set("mapred.child.java.opts", "-Xmx2048m");
    conf.setInt("mapred.task.timeout", 60000000);

    conf.setNumMapTasks(numMappers);// w  w  w  .  j a va 2 s .co m
    conf.setNumReduceTasks(numReducers);

    conf.setMapperClass(Map.class);
    conf.setCombinerClass(Reduce.class);
    conf.setReducerClass(Reduce.class);

    conf.setOutputKeyClass(Text.class);
    conf.setOutputValueClass(ArrayListWritable.class);

    conf.setInputFormat(SequenceFileInputFormat.class);
    conf.setOutputFormat(SequenceFileOutputFormat.class);

    SequenceFileOutputFormat.setCompressOutput(conf, true);
    SequenceFileOutputFormat.setOutputCompressionType(conf, SequenceFile.CompressionType.BLOCK);

    SequenceFileInputFormat.setInputPaths(conf, inputPath);

    FileOutputFormat.setOutputPath(conf, new Path(outputPath));

    LOG.info("ExtractLinks");
    LOG.info(" - input path: " + inputPath);
    LOG.info(" - output path: " + outputPath);
    LOG.info(" - mapping file: " + mappingFile);
    LOG.info(" - include internal links? " + conf.getBoolean("Cloud9.IncludeInternalLinks", false));

    if (!fs.exists(new Path(outputPath))) {
        JobClient.runJob(conf);
    } else {
        LOG.info(outputPath + " already exists! Skipping this step...");
    }

    return 0;
}

From source file:edu.umn.cs.spatialHadoop.nasa.DistributedAggregateSpatioTemporalIndexer.java

License:Open Source License

/**
 * Build a bunch of AggregateQuadTrees using a Map-Reduce job
 * //from   ww w.j  a v a  2  s  . c  o  m
 * @param inputPathsDictionaryPath
 * @param params
 * @throws IOException
 */
public static void aggregateQuadTreeMapReduce(Path inputPathsDictionaryPath, OperationsParams params)
        throws IOException {

    // configure a map-reduce job
    JobConf job = new JobConf(params, DistributedAggregateSpatioTemporalIndexer.class);

    Path outputPath;
    String outputPathPrefix = "aggQuadTree_";
    FileSystem outFs = FileSystem.get(job);
    do {
        outputPath = new Path(outputPathPrefix + (int) (Math.random() * 1000000));
    } while (outFs.exists(outputPath));

    job.setJobName("AggregateQuadTree");
    job.setMapOutputKeyClass(Text.class);
    job.setMapOutputValueClass(Text.class);
    job.setMapperClass(AggregateQuadTreeMaper.class);
    job.set(HDFSIndexPath, hdfsIndexPath.toString());

    ClusterStatus clusterStatus = new JobClient(job).getClusterStatus();
    job.setNumMapTasks(clusterStatus.getMaxMapTasks() * 5);
    job.setInputFormat(TextInputFormat.class);
    job.setOutputFormat(TextOutputFormat.class);

    TextInputFormat.setInputPaths(job, inputPathsDictionaryPath);
    TextOutputFormat.setOutputPath(job, outputPath);

    if (job.getBoolean("local", false)) {
        // Enforce local execution if explicitly set by user or for small
        // files
        job.set("mapred.job.tracker", "local");
        // Use multithreading too
        job.setInt(LocalJobRunner.LOCAL_MAX_MAPS, 16);
    }
    job.setNumReduceTasks(0);

    // Submit the job
    JobClient.runJob(job);

    outFs.delete(outputPath, true);
}

From source file:edu.umn.cs.spatialHadoop.operations.Aggregate.java

License:Open Source License

/**
 * Counts the exact number of lines in a file by issuing a MapReduce job
 * that does the thing/*from  w  ww .jav  a  2 s .  com*/
 * @param files
 * @param params
 * @return
 * @throws IOException
 */
public static MinMax aggregateMapReduce(Path[] files, OperationsParams params) throws IOException {
    Shape plotRange = params.getShape("rect");
    JobConf job = new JobConf(params, Aggregate.class);

    Path outputPath;
    FileSystem outFs = FileSystem.get(job);
    do {
        outputPath = new Path("agg_" + (int) (Math.random() * 1000000));
    } while (outFs.exists(outputPath));

    job.setJobName("Aggregate");
    job.setMapOutputKeyClass(NullWritable.class);
    job.setMapOutputValueClass(MinMax.class);

    job.setMapperClass(Map.class);
    job.setCombinerClass(Reduce.class);
    job.setReducerClass(Reduce.class);
    ClusterStatus clusterStatus = new JobClient(job).getClusterStatus();
    job.setNumMapTasks(clusterStatus.getMaxMapTasks() * 5);

    job.setInputFormat(ShapeInputFormat.class);
    job.setClass("shape", NASAPoint.class, Shape.class);
    if (plotRange != null) {
        job.setClass(SpatialSite.FilterClass, RangeFilter.class, BlockFilter.class);
    }

    job.setOutputFormat(TextOutputFormat.class);

    ShapeInputFormat.setInputPaths(job, files);
    TextOutputFormat.setOutputPath(job, outputPath);

    // Submit the job
    JobClient.runJob(job);

    // Read job result
    FileStatus[] results = outFs.listStatus(outputPath);
    MinMax minMax = new MinMax();
    for (FileStatus status : results) {
        if (status.getLen() > 0 && status.getPath().getName().startsWith("part-")) {
            BufferedReader reader = new BufferedReader(new InputStreamReader(outFs.open(status.getPath())));
            String line;
            MinMax value = new MinMax();
            while ((line = reader.readLine()) != null) {
                value.fromText(new Text(line));
                minMax.expand(value);
            }
            reader.close();
        }
    }

    outFs.delete(outputPath, true);

    return minMax;
}

From source file:edu.umn.cs.spatialHadoop.operations.CatUnion.java

License:Open Source License

/**
 * Calculates the union of a set of shapes categorized by some user defined
 * category./*from www.  j  av  a 2 s.c  o m*/
 * @param shapeFile - Input file that contains shapes
 * @param categoryFile - Category file that contains the category of each
 *  shape.Shapes not appearing in this file are not generated in output.
 * @param output - An output file that contains each category and the union
 *  of all shapes in it. Each line contains the category, then a comma,
 *   then the union represented as text.
 * @throws IOException
 */
public static void unionMapReduce(Path shapeFile, Path categoryFile, Path output, OperationsParams params)
        throws IOException {

    JobConf job = new JobConf(params, CatUnion.class);
    job.setJobName("Union");

    // Check output file existence
    FileSystem outFs = output.getFileSystem(job);
    if (outFs.exists(output)) {
        if (params.getBoolean("overwrite", false)) {
            outFs.delete(output, true);
        } else {
            throw new RuntimeException("Output path already exists and -overwrite flag is not set");
        }
    }

    // Set map and reduce
    ClusterStatus clusterStatus = new JobClient(job).getClusterStatus();
    job.setNumMapTasks(clusterStatus.getMaxMapTasks() * 5);
    job.setNumReduceTasks(Math.max(1, clusterStatus.getMaxReduceTasks() * 9 / 10));

    job.setMapperClass(UnionMapper.class);
    job.setCombinerClass(UnionReducer.class);
    job.setReducerClass(UnionReducer.class);

    job.setMapOutputKeyClass(IntWritable.class);
    job.setMapOutputValueClass(Text.class);

    // Set input and output
    job.setInputFormat(ShapeLineInputFormat.class);
    TextInputFormat.addInputPath(job, shapeFile);
    DistributedCache.addCacheFile(categoryFile.toUri(), job);

    job.setOutputFormat(TextOutputFormat.class);
    TextOutputFormat.setOutputPath(job, output);

    // Start job
    JobClient.runJob(job);
}

From source file:edu.umn.cs.spatialHadoop.operations.ClosestPairHadoop.java

License:Open Source License

/**
 * Counts the exact number of lines in a file by issuing a MapReduce job
 * that does the thing// w w w  .j  a  va2  s.com
 * @param conf
 * @param fs
 * @param file
 * @return
 * @throws IOException 
 */
public static <S extends Shape> void cloesetPair(Path file, OperationsParams params) throws IOException {
    // Try to get file MBR from the MBRs of blocks
    JobConf job = new JobConf(params, ClosestPairHadoop.class);

    Path outputPath;
    FileSystem outFs = FileSystem.get(job);
    do {
        outputPath = new Path(file.getName() + ".closest_pair_" + (int) (Math.random() * 1000000));
    } while (outFs.exists(outputPath));
    outFs.delete(outputPath, true);

    job.setJobName("ClosestPair");
    job.setMapOutputKeyClass(IntWritable.class);
    job.setMapOutputValueClass(Point.class);

    job.setMapperClass(Map0.class);
    job.setReducerClass(Reduce0.class);
    ClusterStatus clusterStatus = new JobClient(job).getClusterStatus();
    job.setNumMapTasks(clusterStatus.getMaxMapTasks() * 5);

    job.setInputFormat(ShapeArrayInputFormat.class);
    //      job.setInputFormat(ShapeInputFormat.class);
    ShapeInputFormat.setInputPaths(job, file);

    job.setOutputFormat(TextOutputFormat.class);
    TextOutputFormat.setOutputPath(job, outputPath);

    // Submit the job
    JobClient.runJob(job);
    //////////////////////////////////////////////////////////////////////////

    System.out.println("Begin second round!");
    // 2nd Round
    job = new JobConf(params, ClosestPairHadoop.class);
    job.setJobName("Second Round");
    job.setOutputKeyClass(NullWritable.class);
    job.setMapOutputValueClass(Point.class);

    job.setMapperClass(Map1.class);
    job.setReducerClass(Reduce1.class);
    clusterStatus = new JobClient(job).getClusterStatus();
    job.setNumMapTasks(clusterStatus.getMaxMapTasks() * 5);

    job.setInputFormat(ShapeArrayInputFormat.class);
    //      job.setInputFormat(ShapeInputFormat.class);
    ShapeInputFormat.setInputPaths(job, outputPath); // The previous output is the current input

    Path newPath = new Path(outputPath.getName() + "_result");
    job.setOutputFormat(TextOutputFormat.class);
    TextOutputFormat.setOutputPath(job, newPath);

    JobClient.runJob(job);
}

From source file:edu.umn.cs.spatialHadoop.operations.Contains.java

License:Open Source License

public static <S extends Shape> long contains(Path[] inFiles, Path userOutputPath, OperationsParams params)
        throws IOException, InterruptedException {
    JobConf job = new JobConf(params, Contains.class);

    LOG.info("Contains journey starts ....");
    FileSystem inFs = inFiles[0].getFileSystem(job);
    Path outputPath = userOutputPath;
    if (outputPath == null) {
        FileSystem outFs = FileSystem.get(job);
        do {/* w ww.  ja v  a2  s  .c o m*/
            outputPath = new Path(inFiles[0].getName() + ".sjmr_" + (int) (Math.random() * 1000000));
        } while (outFs.exists(outputPath));
    }
    FileSystem outFs = outputPath.getFileSystem(job);

    ClusterStatus clusterStatus = new JobClient(job).getClusterStatus();
    job.setJobName("Within");
    job.setMapperClass(ContainsMap.class);
    job.setMapOutputKeyClass(IntWritable.class);
    job.setMapOutputValueClass(IndexedText.class);
    job.setNumMapTasks(5 * Math.max(1, clusterStatus.getMaxMapTasks()));
    job.setLong("mapred.min.split.size", Math.max(inFs.getFileStatus(inFiles[0]).getBlockSize(),
            inFs.getFileStatus(inFiles[1]).getBlockSize()));

    job.setReducerClass(ContainsReduce.class);
    job.setNumReduceTasks(Math.max(1, clusterStatus.getMaxReduceTasks()));

    job.setInputFormat(ShapeLineInputFormat.class);
    if (job.getBoolean("output", true))
        job.setOutputFormat(TextOutputFormat.class);
    else
        job.setOutputFormat(NullOutputFormat.class);
    ShapeLineInputFormat.setInputPaths(job, inFiles);

    // Calculate and set the dimensions of the grid to use in the map phase
    long total_size = 0;
    Rectangle mbr = new Rectangle(Double.MAX_VALUE, Double.MAX_VALUE, -Double.MAX_VALUE, -Double.MAX_VALUE);
    for (Path file : inFiles) {
        FileSystem fs = file.getFileSystem(params);
        Rectangle file_mbr = FileMBR.fileMBR(file, params);
        mbr.expand(file_mbr);
        total_size += FileUtil.getPathSize(fs, file);
    }
    // If the largest file is globally indexed, use its partitions
    total_size += total_size * job.getFloat(SpatialSite.INDEXING_OVERHEAD, 0.2f);
    int sjmrPartitioningGridFactor = params.getInt(PartitioiningFactor, 20);
    int num_cells = (int) Math.max(1,
            total_size * sjmrPartitioningGridFactor / outFs.getDefaultBlockSize(outputPath));
    LOG.info("Number of cells is configured to be " + num_cells);

    OperationsParams.setInactiveModeFlag(job, InactiveMode, isReduceInactive);
    OperationsParams.setJoiningThresholdPerOnce(job, JoiningThresholdPerOnce, joiningThresholdPerOnce);
    OperationsParams.setFilterOnlyModeFlag(job, isFilterOnlyMode, isFilterOnly);

    GridInfo gridInfo = new GridInfo(mbr.x1, mbr.y1, mbr.x2, mbr.y2);
    gridInfo.calculateCellDimensions(num_cells);
    OperationsParams.setShape(job, PartitionGrid, gridInfo);

    TextOutputFormat.setOutputPath(job, outputPath);

    if (OperationsParams.isLocal(job, inFiles)) {
        // Enforce local execution if explicitly set by user or for small files
        job.set("mapred.job.tracker", "local");
    }

    // Start the job
    RunningJob runningJob = JobClient.runJob(job);
    Counters counters = runningJob.getCounters();
    Counter outputRecordCounter = counters.findCounter(Task.Counter.REDUCE_OUTPUT_RECORDS);
    final long resultCount = outputRecordCounter.getValue();

    return resultCount;
}