[MAPREDUCE-5723] MR AM container log can be truncated or empty

• Type: Bug
• Status: Closed
• Priority: Blocker
• Resolution: Fixed
• Affects Version/s: 2.2.0
• Fix Version/s: 2.3.0
• Component/s: applicationmaster
• Hadoop Flags: Reviewed
• Assignee: Mohammad Islam
• Reporter: Mohammad Islam
• Created: 14/Jan/14 22:43
• Updated: 24/Feb/14 20:56
• Resolved: 23/Jan/14 06:09

Description

It occurs when the property "mapreduce.task.userlog.limit.kb" is set non-zero in mapped-site.xml.
AM container syslog remains empty if any exception occurs.

Bug details:
In MRAppMaster.java, the following code snippets show the bug.

    } catch (Throwable t) {
       LOG.fatal("Error starting MRAppMaster", t);
      System.exit(1);
    }finally {
       LogManager.shutdown();
    }

In the catch block, we are exiting the JVM. So finally block (therefore LogManager.shutdown()) is never executed.

Possible fix:
Make sure LogManager.shutdown() is executed in all cases.

Issue Links

• relates to: MAPREDUCE-5730 AM log is truncated