[MAPREDUCE-1423] Improve performance of CombineFileInputFormat when multiple pools are configured

• Type: Improvement
• Status: Closed
• Priority: Major
• Resolution: Fixed
• Fix Version/s: 0.21.0
• Component/s: client
• Hadoop Flags: Reviewed

Release Note

MAPREDUCE-1423. Improve performance of CombineFileInputFormat when multiple pools are configured. (Dhruba Borthakur via zshao)

• Tags: combinefileinputformat
• Assignee: Dhruba Borthakur
• Reporter: Dhruba Borthakur
• Created: 28/Jan/10 08:45
• Updated: 24/Aug/10 21:20
• Resolved: 03/Mar/10 08:17

Description

I have a map-reduce job that is using CombineFileInputFormat. It has configured 10000 pools and 30000 files. The time to create the splits takes more than an hour. The reaosn being that CombineFileInputFormat.getSplits() converts the same path from String to Path object multiple times, one for each instance of a pool. Similarly, it calls Path.toUri(0 multiple times. This code can be optimized.