public static JobInfo getJobInfo(HttpServletRequest request, FileSystem fs)
    throws IOException {
  String jobid = request.getParameter("jobid");
  String logFile = request.getParameter("logFile");
  synchronized(jobHistoryCache) {
    JobInfo jobInfo = jobHistoryCache.remove(jobid);
    if (jobInfo == null) {
      jobInfo = new JobHistory.JobInfo(jobid);
      LOG.info("Loading Job History file "+jobid + ".   Cache size is " +
          jobHistoryCache.size());
      DefaultJobHistoryParser.parseJobTasks( logFile, jobInfo, fs) ;
    }
    jobHistoryCache.put(jobid, jobInfo);
    if (jobHistoryCache.size() > CACHE_SIZE) {
      Iterator<Map.Entry<String, JobInfo>> it =
        jobHistoryCache.entrySet().iterator();
      String removeJobId = it.next().getKey();
      it.remove();
      LOG.info("Job History file removed form cache "+removeJobId);
    }
    return jobInfo;
  }
}
 

/**
 * @param jobConfFile - URL pointing to job configuration (job_conf.xml) file
 * @param jobHistoryLogFile - URL pointing to job history log file  
 * @param testsConfFile - file path for test configuration file (optional). 
 * If not specified default path is:$HADOOP_HOME/contrib/vaidya/pxpd_tests_config.xml
 * @param reportFile - file path for storing report (optional)
 */
public PostExPerformanceDiagnoser (String jobConfFile, String jobHistoryFile, InputStream testsConfFileIs,
              String reportFile) throws Exception {
  
  this._jobHistoryFile = jobHistoryFile;
  this._testsConfFileIs = testsConfFileIs;
  this._reportFile = reportFile;
  this._jobConfFile = jobConfFile;
  
  /*
   * Read the job information necessary for post performance analysis
   */
  JobConf jobConf = new JobConf();
  JobInfo jobInfo = new JobInfo("");
  readJobInformation(jobConf, jobInfo);
  this._jobExecutionStatistics = new JobStatistics(jobConf, jobInfo);
}
 

/**
 * read and populate job statistics information.
 */
private void readJobInformation(JobConf jobConf, JobInfo jobInfo) throws Exception {

  /*
   * Convert the input strings to URL
   */
  URL jobConfFileUrl = new URL(this._jobConfFile);
  URL jobHistoryFileUrl = new URL (this._jobHistoryFile);
  
  /*
   * Read the Job Configuration from the jobConfFile url
   */  
  jobConf.addResource(jobConfFileUrl);
  
  /* 
   * Read JobHistoryFile and build job counters to evaluate diagnostic rules
   */
  if (jobHistoryFileUrl.getProtocol().equals("hdfs")) {
    DefaultJobHistoryParser.parseJobTasks (jobHistoryFileUrl.getPath(), jobInfo, FileSystem.get(jobConf));
  } else if (jobHistoryFileUrl.getProtocol().equals("file")) {
    DefaultJobHistoryParser.parseJobTasks (jobHistoryFileUrl.getPath(), jobInfo, FileSystem.getLocal(jobConf));
  } else {
    throw new Exception("Malformed URL. Protocol: "+jobHistoryFileUrl.getProtocol());
  }
}
 

/**
 * @param jobConfFile - URL pointing to job configuration (job_conf.xml) file
 * @param jobHistoryLogFile - URL pointing to job history log file  
 * @param testsConfFile - file path for test configuration file (optional). 
 * If not specified default path is:$HADOOP_HOME/contrib/vaidya/pxpd_tests_config.xml
 * @param reportFile - file path for storing report (optional)
 */
public PostExPerformanceDiagnoser (String jobConfFile, String jobHistoryFile, InputStream testsConfFileIs,
              String reportFile) throws Exception {
  
  this._jobHistoryFile = jobHistoryFile;
  this._testsConfFileIs = testsConfFileIs;
  this._reportFile = reportFile;
  this._jobConfFile = jobConfFile;
  
  /*
   * Read the job information necessary for post performance analysis
   */
  JobConf jobConf = new JobConf();
  JobInfo jobInfo = new JobInfo("");
  readJobInformation(jobConf, jobInfo);
  this._jobExecutionStatistics = new JobStatistics(jobConf, jobInfo);
}
 

/**
 * read and populate job statistics information.
 */
private void readJobInformation(JobConf jobConf, JobInfo jobInfo) throws Exception {

  /*
   * Convert the input strings to URL
   */
  URL jobConfFileUrl = new URL(this._jobConfFile);
  URL jobHistoryFileUrl = new URL (this._jobHistoryFile);
  
  /*
   * Read the Job Configuration from the jobConfFile url
   */  
  jobConf.addResource(jobConfFileUrl);
  
  /* 
   * Read JobHistoryFile and build job counters to evaluate diagnostic rules
   */
  if (jobHistoryFileUrl.getProtocol().equals("hdfs")) {
    DefaultJobHistoryParser.parseJobTasks (jobHistoryFileUrl.getPath(), jobInfo, FileSystem.get(jobConf));
  } else if (jobHistoryFileUrl.getProtocol().equals("file")) {
    DefaultJobHistoryParser.parseJobTasks (jobHistoryFileUrl.getPath(), jobInfo, FileSystem.getLocal(jobConf));
  } else {
    throw new Exception("Malformed URL. Protocol: "+jobHistoryFileUrl.getProtocol());
  }
}
 

public static void parseJobHistory(Configuration jobConf, JobInfo jobInfo, MRJobInfo value) {
    value.job.clear();
    populateJob(jobInfo.getValues(), value.job);
    value.mapTask.clear();
    value.reduceTask.clear();
    populateMapReduceTaskLists(value, jobInfo.getAllTasks());
}
 

/**
 * Tests the JobHistory parser with different versions of job history files
 */
public void testJobHistoryVersion() throws IOException {
  // If new job history version comes up, the modified parser may fail for
  // the history file created by writeHistoryFile().
  for (long version = 0; version <= JobHistory.VERSION; version++) {
    JobConf conf = new JobConf();
    FileSystem fs = FileSystem.getLocal(conf);
  
    // cleanup
    fs.delete(TEST_DIR, true);
  
    Path historyPath = new Path(TEST_DIR + "/_logs/history/" +
                                FILENAME + version);
  
    fs.delete(historyPath, false);
  
    FSDataOutputStream out = fs.create(historyPath);
    writeHistoryFile(out, version);
    out.close();
  
    JobInfo job = new JobHistory.JobInfo(JOB); 
    DefaultJobHistoryParser.parseJobTasks(historyPath.toString(), job, fs);
  
    assertTrue("Failed to parse jobhistory files of version " + version,
               job.getAllTasks().size() > 0);
  
    // cleanup
    fs.delete(TEST_DIR, true);
  }
}
 

public JobStatistics (JobConf jobConf, JobInfo jobInfo) throws ParseException {
  this._jobConf = jobConf;
  this._jobInfo = jobInfo;
  this._job = new Hashtable<Enum, String>();
  populate_Job(this._job, this._jobInfo.getValues());  
  populate_MapReduceTaskLists(this._mapTaskList, this._reduceTaskList, this._jobInfo.getAllTasks());

  // Add the Job Type: MAP_REDUCE, MAP_ONLY
  if (getLongValue(JobKeys.TOTAL_REDUCES) == 0) {
    this._job.put(JobKeys.JOBTYPE,"MAP_ONLY");
  } else {
    this._job.put(JobKeys.JOBTYPE,"MAP_REDUCE");
  }
}
 

/**
 * Tests the JobHistory parser with different versions of job history files
 */
public void testJobHistoryVersion() throws IOException {
  // If new job history version comes up, the modified parser may fail for
  // the history file created by writeHistoryFile().
  for (long version = 0; version <= JobHistory.VERSION; version++) {
    JobConf conf = new JobConf();
    FileSystem fs = FileSystem.getLocal(conf);
  
    // cleanup
    fs.delete(TEST_DIR, true);
  
    Path historyPath = new Path(TEST_DIR + "/_logs/history/" +
                                FILENAME + version);
  
    fs.delete(historyPath, false);
  
    FSDataOutputStream out = fs.create(historyPath);
    writeHistoryFile(out, version);
    out.close();
  
    JobInfo job = new JobHistory.JobInfo(JOB); 
    DefaultJobHistoryParser.parseJobTasks(historyPath.toString(), job, fs);
  
    assertTrue("Failed to parse jobhistory files of version " + version,
               job.getAllTasks().size() > 0);
  
    // cleanup
    fs.delete(TEST_DIR, true);
  }
}
 

public JobStatistics (JobConf jobConf, JobInfo jobInfo) throws ParseException {
  this._jobConf = jobConf;
  this._jobInfo = jobInfo;
  this._job = new Hashtable<Enum, String>();
  populate_Job(this._job, this._jobInfo.getValues());
  populate_MapReduceTaskLists(this._mapTaskList, this._reduceTaskList, this._jobInfo.getAllTasks());
}
 

@Override
public boolean nextKeyValue() throws IOException, InterruptedException {
    if (location != null) {
        LOG.info("load: " + location);  
        Path full = new Path(location);  
        String[] jobDetails = 
            JobInfo.decodeJobHistoryFileName(full.getName()).split("_");
        String jobId = jobDetails[2] + "_" + jobDetails[3] + "_"
                + jobDetails[4];
        JobHistory.JobInfo job = new JobHistory.JobInfo(jobId); 
 
        value = new MRJobInfo();
                                    
        FileSystem fs = full.getFileSystem(conf);
        FileStatus fstat = fs.getFileStatus(full);
        
        LOG.info("file size: " + fstat.getLen());
        DefaultJobHistoryParser.parseJobTasks(location, job,
                full.getFileSystem(conf)); 
        LOG.info("job history parsed sucessfully");
        HadoopJobHistoryLoader.parseJobHistory(conf, job, value);
        LOG.info("get parsed job history");
        
        // parse Hadoop job xml file
        Path parent = full.getParent();
        String jobXml = jobDetails[0] + "_" + jobDetails[1] + "_" + jobDetails[2] + "_conf.xml";
        Path p = new Path(parent, jobXml);  
     
        FSDataInputStream fileIn = fs.open(p);
        Map<String, String> val = HadoopJobHistoryLoader
                .parseJobXML(fileIn);
        for (String key : val.keySet()) {
            value.job.put(key, val.get(key));
        }
        
        location = null;
        return true;
    }          
    value = null;
    return false;
}