[HADOOP-3961] resource estimation works badly in some cases

• Type: Bug
• Status: Closed
• Priority: Blocker
• Resolution: Fixed
• Affects Version/s: 0.19.0
• Fix Version/s: 0.19.0
• Hadoop Flags: Reviewed
• Assignee: Ariel Shemaiah Rabkin
• Reporter: Ariel Shemaiah Rabkin
• Created: 15/Aug/08 21:39
• Updated: 08/Jul/09 16:52
• Resolved: 27/Aug/08 06:40

Description

The disk space estimation introduced in HADOOP-657 performs badly under some circumstances. In particular, if maps have very small output, the initial estimate of output size equals input size throws everything off.

Fix is to use a smaller initial estimate, and to update it appropriately.