[HADOOP-5728] FSEditLog.printStatistics may cause IndexOutOfBoundsException

• Type: Bug
• Status: Closed
• Priority: Major
• Resolution: Fixed
• Affects Version/s: 0.19.1
• Fix Version/s: 0.19.2

Environment

jdk 1.6, centOS 5.2 and hadoop 0.19.1

• Hadoop Flags: Reviewed
• Assignee: Wang Xu
• Reporter: Wang Xu
• Created: 23/Apr/09 13:50
• Updated: 03/Aug/09 12:59
• Resolved: 22/May/09 16:17

Description

We met IndexOutOfBoundsException exception when did logSync or rollEditlog,
the direct reason is the printStatistics of FSEditLog used the first element of
StringArray editStreams, but does not check whether editStreams is empty when
it is not null. As below:

if (editStreams == null )

{ return; }

.....[snipped]....
buf.append(" Number of syncs: " + editStreams.get(0).getNumSync());

the simple solution is to check whether it is empty.