Java JobContext類代碼示例

import org.apache.hadoop.mapreduce.JobContext; //導入依賴的package包/類
@Override
public List<InputSplit> getSplits(JobContext jobCtxt) throws IOException {
  final JobClient client =
    new JobClient(new JobConf(jobCtxt.getConfiguration()));
  ClusterStatus stat = client.getClusterStatus(true);
  final long toGen =
    jobCtxt.getConfiguration().getLong(GRIDMIX_GEN_BYTES, -1);
  if (toGen < 0) {
    throw new IOException("Invalid/missing generation bytes: " + toGen);
  }
  final int nTrackers = stat.getTaskTrackers();
  final long bytesPerTracker = toGen / nTrackers;
  final ArrayList<InputSplit> splits = new ArrayList<InputSplit>(nTrackers);
  final Pattern trackerPattern = Pattern.compile("tracker_([^:]*):.*");
  final Matcher m = trackerPattern.matcher("");
  for (String tracker : stat.getActiveTrackerNames()) {
    m.reset(tracker);
    if (!m.find()) {
      System.err.println("Skipping node: " + tracker);
      continue;
    }
    final String name = m.group(1);
    splits.add(new GenSplit(bytesPerTracker, new String[] { name }));
  }
  return splits;
}
 

import org.apache.hadoop.mapreduce.JobContext; //導入依賴的package包/類
private List<InputSplit> createSplits(JobContext jobContext, List<DynamicInputChunk> chunks) throws IOException {
  int numMaps = getNumMapTasks(jobContext.getConfiguration());

  final int nSplits = Math.min(numMaps, chunks.size());
  List<InputSplit> splits = new ArrayList<>(nSplits);

  for (int i = 0; i < nSplits; ++i) {
    TaskID taskId = new TaskID(jobContext.getJobID(), TaskType.MAP, i);
    chunks.get(i).assignTo(taskId);
    splits.add(new FileSplit(chunks.get(i).getPath(), 0,
        // Setting non-zero length for FileSplit size, to avoid a possible
        // future when 0-sized file-splits are considered "empty" and skipped
        // over.
        getMinRecordsPerChunk(jobContext.getConfiguration()), null));
  }
  ConfigurationUtil.publish(jobContext.getConfiguration(), CONF_LABEL_NUM_SPLITS, splits.size());
  return splits;
}
 

import org.apache.hadoop.mapreduce.JobContext; //導入依賴的package包/類
@Override
public List<InputSplit> getSplits(JobContext context) throws IOException {
  List<InputSplit> allSplits = new ArrayList<InputSplit>();
  Scan originalScan = getScan();

  Scan[] scans = rowKeyDistributor.getDistributedScans(originalScan);

  for (Scan scan : scans) {
    // Internally super.getSplits(...) uses scan object stored in private variable,
    // to re-use the code of super class we switch scan object with scans we
    setScan(scan);
    List<InputSplit> splits = super.getSplits(context);
    allSplits.addAll(splits);
  }

  // Setting original scan back
  setScan(originalScan);

  return allSplits;
}
 

import org.apache.hadoop.mapreduce.JobContext; //導入依賴的package包/類
private int getDesiredNumberOfMappers(JobContext jobContext) {

    int desiredNumberOfMappers =
        jobContext.getConfiguration().getInt(
            OraOopConstants.ORAOOP_DESIRED_NUMBER_OF_MAPPERS, -1);

    int minMappersAcceptedByOraOop =
        OraOopUtilities.getMinNumberOfImportMappersAcceptedByOraOop(jobContext
            .getConfiguration());

    if (desiredNumberOfMappers < minMappersAcceptedByOraOop) {
      LOG.warn(String.format("%s should not be used to perform a sqoop import "
          + "when the number of mappers is %d\n "
          + "i.e. OraOopManagerFactory.accept() should only appect jobs "
          + "where the number of mappers is at least %d",
          OraOopConstants.ORAOOP_PRODUCT_NAME, desiredNumberOfMappers,
          minMappersAcceptedByOraOop));
    }

    return desiredNumberOfMappers;
  }
 

import org.apache.hadoop.mapreduce.JobContext; //導入依賴的package包/類
public void checkOutputSpecs(JobContext job
                             ) throws FileAlreadyExistsException, IOException{
  // Ensure that the output directory is set and not already there
  Path outDir = getOutputPath(job);
  if (outDir == null) {
    throw new InvalidJobConfException("Output directory not set.");
  }

  // get delegation token for outDir's file system
  TokenCache.obtainTokensForNamenodes(job.getCredentials(),
      new Path[] { outDir }, job.getConfiguration());

  if (outDir.getFileSystem(job.getConfiguration()).exists(outDir)) {
    throw new FileAlreadyExistsException("Output directory " + outDir + 
                                         " already exists");
  }
}
 

import org.apache.hadoop.mapreduce.JobContext; //導入依賴的package包/類
@Override
/** {@inheritDoc} */
public void checkOutputSpecs(JobContext context)
    throws IOException, InterruptedException {
  Configuration conf = context.getConfiguration();
  DBConfiguration dbConf = new DBConfiguration(conf);

  // Sanity check all the configuration values we need.
  if (null == conf.get(DBConfiguration.URL_PROPERTY)) {
    throw new IOException("Database connection URL is not set.");
  } else if (null == dbConf.getOutputTableName()) {
    throw new IOException("Table name is not set for export.");
  } else if (null == dbConf.getOutputFieldNames()) {
    throw new IOException(
        "Output field names are null.");
  } else if (null == conf.get(ExportJobBase.SQOOP_EXPORT_UPDATE_COL_KEY)) {
    throw new IOException("Update key column is not set for export.");
  }
}
 

import org.apache.hadoop.mapreduce.JobContext; //導入依賴的package包/類
@Override
/** {@inheritDoc} */
public void checkOutputSpecs(JobContext context)
    throws IOException, InterruptedException {
  Configuration conf = context.getConfiguration();
  DBConfiguration dbConf = new DBConfiguration(conf);

  // Sanity check all the configuration values we need.
  if (null == conf.get(DBConfiguration.URL_PROPERTY)) {
    throw new IOException("Database connection URL is not set.");
  } else if (null == dbConf.getOutputTableName()) {
    throw new IOException("Procedure name is not set for export");
  } else if (null == dbConf.getOutputFieldNames()
      && 0 == dbConf.getOutputFieldCount()) {
    throw new IOException(
        "Output field names are null and zero output field count set.");
  }
}
 

import org.apache.hadoop.mapreduce.JobContext; //導入依賴的package包/類
/** {@inheritDoc} */
public List<InputSplit> getSplits(JobContext context) {
  //get the property values
  final int startDigit = context.getConfiguration().getInt(
      DIGIT_START_PROPERTY, 1);
  final int nDigits = context.getConfiguration().getInt(
      DIGIT_SIZE_PROPERTY, 100);
  final int nMaps = context.getConfiguration().getInt(
      DIGIT_PARTS_PROPERTY, 1);

  //create splits
  final List<InputSplit> splits = new ArrayList<InputSplit>(nMaps);
  final int[] parts = partition(startDigit - 1, nDigits, nMaps);
  for (int i = 0; i < parts.length; ++i) {
    final int k = i < parts.length - 1 ? parts[i+1]: nDigits+startDigit-1;
    splits.add(new BbpSplit(i, parts[i], k - parts[i]));
  }
  return splits;
}
 

import org.apache.hadoop.mapreduce.JobContext; //導入依賴的package包/類
@Override
/** {@inheritDoc} */
public void checkOutputSpecs(JobContext context)
    throws IOException, InterruptedException {
  Configuration conf = context.getConfiguration();
  DBConfiguration dbConf = new DBConfiguration(conf);

  // Sanity check all the configuration values we need.
  if (null == conf.get(DBConfiguration.URL_PROPERTY)) {
    throw new IOException("Database connection URL is not set.");
  } else if (null == dbConf.getOutputTableName()) {
    throw new IOException("Table name is not set for export");
  } else if (null == dbConf.getOutputFieldNames()
      && 0 == dbConf.getOutputFieldCount()) {
    throw new IOException(
        "Output field names are null and zero output field count set.");
  }
}
 

import org.apache.hadoop.mapreduce.JobContext; //導入依賴的package包/類
@Override
@Deprecated
public void cleanupJob(JobContext context) throws IOException {
  if (hasOutputPath()) {
    Path pendingJobAttemptsPath = getPendingJobAttemptsPath();
    FileSystem fs = pendingJobAttemptsPath
        .getFileSystem(context.getConfiguration());
    fs.delete(pendingJobAttemptsPath, true);
  } else {
    LOG.warn("Output Path is null in cleanupJob()");
  }
}
 

import org.apache.hadoop.mapreduce.JobContext; //導入依賴的package包/類
/**
 * Create a local map output index file name on the same volume.
 */
public Path getOutputIndexFileForWriteInVolume(Path existing) {
  Path outputDir = new Path(existing.getParent(), JOB_OUTPUT_DIR);
  Path attemptOutputDir = new Path(outputDir,
      conf.get(JobContext.TASK_ATTEMPT_ID));
  return new Path(attemptOutputDir, MAP_OUTPUT_FILENAME_STRING +
                                    MAP_OUTPUT_INDEX_SUFFIX_STRING);
}
 

import org.apache.hadoop.mapreduce.JobContext; //導入依賴的package包/類
/**
 * The job has completed so move all committed tasks to the final output dir.
 * Delete the temporary directory, including all of the work directories.
 * Create a _SUCCESS file to make it as successful.
 * @param context the job's context
 */
public void commitJob(JobContext context) throws IOException {
  if (hasOutputPath()) {
    Path finalOutput = getOutputPath();
    FileSystem fs = finalOutput.getFileSystem(context.getConfiguration());

    if (algorithmVersion == 1) {
      for (FileStatus stat: getAllCommittedTaskPaths(context)) {
        mergePaths(fs, stat, finalOutput);
      }
    }

    // delete the _temporary folder and create a _done file in the o/p folder
    cleanupJob(context);
    // True if the job requires output.dir marked on successful job.
    // Note that by default it is set to true.
    if (context.getConfiguration().getBoolean(SUCCESSFUL_JOB_OUTPUT_DIR_MARKER, true)) {
      Path markerPath = new Path(outputPath, SUCCEEDED_FILE_NAME);
      fs.create(markerPath).close();
    }
  } else {
    LOG.warn("Output Path is null in commitJob()");
  }
}
 

import org.apache.hadoop.mapreduce.JobContext; //導入依賴的package包/類
/**
 * Returns a split for each store files directory using the block location
 * of each file as locality reference.
 */
@Override
public List<InputSplit> getSplits(JobContext job) throws IOException {
  List<InputSplit> splits = new ArrayList<InputSplit>();
  List<FileStatus> files = listStatus(job);

  Text key = new Text();
  for (FileStatus file: files) {
    Path path = file.getPath();
    FileSystem fs = path.getFileSystem(job.getConfiguration());
    LineReader reader = new LineReader(fs.open(path));
    long pos = 0;
    int n;
    try {
      while ((n = reader.readLine(key)) > 0) {
        String[] hosts = getStoreDirHosts(fs, path);
        splits.add(new FileSplit(path, pos, n, hosts));
        pos += n;
      }
    } finally {
      reader.close();
    }
  }

  return splits;
}
 

import org.apache.hadoop.mapreduce.JobContext; //導入依賴的package包/類
@Test
public void testTransitionsAtFailed() throws IOException {
  Configuration conf = new Configuration();
  AsyncDispatcher dispatcher = new AsyncDispatcher();
  dispatcher.init(conf);
  dispatcher.start();

  OutputCommitter committer = mock(OutputCommitter.class);
  doThrow(new IOException("forcefail"))
    .when(committer).setupJob(any(JobContext.class));
  CommitterEventHandler commitHandler =
      createCommitterEventHandler(dispatcher, committer);
  commitHandler.init(conf);
  commitHandler.start();

  AppContext mockContext = mock(AppContext.class);
  when(mockContext.hasSuccessfullyUnregistered()).thenReturn(false);
  JobImpl job = createStubbedJob(conf, dispatcher, 2, mockContext);
  JobId jobId = job.getID();
  job.handle(new JobEvent(jobId, JobEventType.JOB_INIT));
  assertJobState(job, JobStateInternal.INITED);
  job.handle(new JobStartEvent(jobId));
  assertJobState(job, JobStateInternal.FAILED);

  job.handle(new JobEvent(jobId, JobEventType.JOB_TASK_COMPLETED));
  assertJobState(job, JobStateInternal.FAILED);
  job.handle(new JobEvent(jobId, JobEventType.JOB_TASK_ATTEMPT_COMPLETED));
  assertJobState(job, JobStateInternal.FAILED);
  job.handle(new JobEvent(jobId, JobEventType.JOB_MAP_TASK_RESCHEDULED));
  assertJobState(job, JobStateInternal.FAILED);
  job.handle(new JobEvent(jobId, JobEventType.JOB_TASK_ATTEMPT_FETCH_FAILURE));
  assertJobState(job, JobStateInternal.FAILED);
  Assert.assertEquals(JobState.RUNNING, job.getState());
  when(mockContext.hasSuccessfullyUnregistered()).thenReturn(true);
  Assert.assertEquals(JobState.FAILED, job.getState());

  dispatcher.stop();
  commitHandler.stop();
}
 

import org.apache.hadoop.mapreduce.JobContext; //導入依賴的package包/類
@Override
public List<InputSplit> getSplits(JobContext jobCtxt) throws IOException {
  // get the total data to be generated
  long toGen =
    jobCtxt.getConfiguration().getLong(GenerateData.GRIDMIX_GEN_BYTES, -1);
  if (toGen < 0) {
    throw new IOException("Invalid/missing generation bytes: " + toGen);
  }
  // get the total number of mappers configured
  int totalMappersConfigured =
    jobCtxt.getConfiguration().getInt(MRJobConfig.NUM_MAPS, -1);
  if (totalMappersConfigured < 0) {
    throw new IOException("Invalid/missing num mappers: " 
                          + totalMappersConfigured);
  }
  
  final long bytesPerTracker = toGen / totalMappersConfigured;
  final ArrayList<InputSplit> splits = 
    new ArrayList<InputSplit>(totalMappersConfigured);
  for (int i = 0; i < totalMappersConfigured; ++i) {
    splits.add(new GenSplit(bytesPerTracker, 
               new String[] { "tracker_local" }));
  }
  return splits;
}