code: String[][] findPartitionInfo(String hostName, String userDir, String libertyServerName, String executorIdentifier) throws Exception {
          PartitionRecord criteria = new PartitionRecord(false);
          if (hostName != null)
              criteria.setHostName(hostName);
          if (userDir != null)
              criteria.setUserDir(userDir);
          if (libertyServerName != null)
              criteria.setLibertyServer(libertyServerName);
          if (executorIdentifier != null)
              criteria.setExecutor(executorIdentifier);
  
          List<PartitionRecord> records = null;
          TransactionController tranController = new TransactionController();
          try {
              tranController.preInvoke();
              records = taskStore.find(criteria);
          } catch (Throwable x) {
              tranController.setFailure(x);
          } finally {
              Exception x = tranController.postInvoke(Exception.class);
              if (x != null)
                  throw x;
          }
  
          String[][] partitionInfo = new String[records == null ? 0 : records.size()][5];
          if (records != null) // guard against impossible null value to make FindBugs stop complaining
              for (int i = 0; i < records.size(); i++) {
                  PartitionRecord record = records.get(i);
                  partitionInfo[i][0] = Long.toString(record.getId());
                  partitionInfo[i][1] = record.getHostName();
                  partitionInfo[i][2] = record.getUserDir();
                  partitionInfo[i][3] = record.getLibertyServer();
                  partitionInfo[i][4] = record.getExecutor();
              }
          return partitionInfo;
      }
docs: Finds partition information in the persistent store. All of the parameters are optional.
  If a parameter is specified, only entries that match it are retrieved from the persistent store.
  
  This method is for the mbean only.
  
  @param hostName the host name.
  @param userDir wlp.user.dir
  @param libertyServerName name of the Liberty server.
  @param executorIdentifier config.displayId of the persistent executor.
  @return a list of partition information. Each entry in the list consists of
  (partitionId, hostName, userDir, libertyServerName, executorIdentifier)
  @throws Exception if an error occurs.