[HADOOP-3970] Counters written to the job history cannot be recovered back

• Type: Bug
• Status: Closed
• Priority: Major
• Resolution: Fixed
• Fix Version/s: 0.19.0
• Hadoop Flags: Reviewed
• Release Note: Added getEscapedCompactString() and fromEscapedCompactString() to Counters.java to represent counters as Strings and to reconstruct the counters from the Strings.
• Assignee: Amar Kamat
• Reporter: Amar Kamat
• Created: 19/Aug/08 09:43
• Updated: 02/May/13 02:29
• Resolved: 09/Sep/08 07:04

Description

Counters that are written to the JobHistory are stringified using Counters.makeCompactString(). The format in which this api converts the counter into a string is groupname.countername:value. The problem is that groupname and countername can contain a '.' and hence recovering the counter becomes difficult. Since JobHistory can be used for various purposes, reconstructing the counter object back might be useful. One such usecase is HADOOP-3245. There should be some way to recover the counter object back from its string representation and also to keep the string version readable.

Issue Links

• is depended upon by: HADOOP-3245 Provide ability to persist running jobs (extend HADOOP-1876)