[HBASE-8367] LoadIncrementalHFiles does not return an error code nor throw Exception when failures occur due to timeouts

• Type: Improvement
• Status: Closed
• Priority: Minor
• Resolution: Fixed
• Affects Version/s: 0.92.1, 0.92.2
• Fix Version/s: 0.98.0, 0.94.8, 0.95.1
• Component/s: mapreduce

Environment

Red Hat 6.2
Java 1.6.0_26
Hadoop 2.0.0-mr1-cdh4.1.1
HBase 0.92.1-cdh4.1.1

• Hadoop Flags: Reviewed
• Assignee: Brian Dougan
• Reporter: Brian Dougan
• Created: 17/Apr/13 21:06
• Updated: 04/Jun/13 00:06
• Resolved: 13/May/13 22:09

Description

The LoadIncrementalHFiles (completebulkload) command will exit with a success code (or lack of Exception) when one or more of the HFiles fail to be imported through a few ways (mainly when timeouts occur). Instead, it simply logs error messages to the log which makes it difficult to automate the import of HFiles programmatically.

The heart of the LoadIncrementalHFiles class (doBulkLoad) returns void and has essentially the following structure.

LoadIncrementalHFiles.java

try {
      ...
 
    } finally {
      pool.shutdown();
      if (queue != null && !queue.isEmpty()) {
        StringBuilder err = new StringBuilder();
        err.append("-------------------------------------------------\n");
        err.append("Bulk load aborted with some files not yet loaded:\n");
        err.append("-------------------------------------------------\n");
        for (LoadQueueItem q : queue) {
          err.append("  ").append(q.hfilePath).append('\n');
        }
        LOG.error(err);
      }
    }

As you can see, instead of returning an error code, a success indicator, or simply throwing an Exception, an error message is sent to the log. This results in something like the following in the logs.

Bulk load aborted with some files not yet loaded:
-------------------------------------------------
hdfs://prmdprod/user/userxxx/hfile/TABLE-1365721885510/record/_tmp/TABLE,2.bottom
hdfs://prmdprod/user/userxxx/hfile/TABLE-1365721885510/record/_tmp/TABLE,2.top
hdfs://prmdprod/user/userxxx/hfile/TABLE-1365721885510/record/_tmp/TABLE,1.bottom
hdfs://prmdprod/user/userxxx/hfile/TABLE-1365721885510/record/_tmp/TABLE,1.top

Without some sort of indication, it's not currently possible to chain this command to another or to programmatically consume this class and be certain of a successful import.

This class should be enhanced to return non-success in whatever way makes sense to the community. I don't really have a strong preference, but one of the following should work fine (at least for my needs).

• boolean return value on doBulkLoad (non-zero on run method)
• Response object on doBulkLoad detailing the files that failed (non-zero on run method)
• throw Exception in the finally block when files failed after the error is written to the log (should automatically cause non-zero on run method)

It would also be nice to get this to the 0.94.x stream so it get included in the next Cloudera release. Thanks!