[MAPREDUCE-3289] Make use of fadvise in the NM's shuffle handler

• Type: Improvement
• Status: Closed
• Priority: Major
• Resolution: Fixed
• Affects Version/s: 0.23.0
• Fix Version/s: 1.1.0, 2.0.2-alpha
• Component/s: mrv2, nodemanager, performance
• Target Version/s: 2.0.0-alpha
• Hadoop Flags: Reviewed
• Assignee: Todd Lipcon
• Reporter: Todd Lipcon
• Created: 28/Oct/11 00:07
• Updated: 11/Oct/12 17:48
• Resolved: 02/Aug/12 22:00

Description

Using the new NativeIO fadvise functions, we can make the NodeManager prefetch map output before it's send over the socket, and drop it out of the fs cache once it's been sent (since it's very rare for an output to have to be re-sent). This improves IO efficiency and reduces cache pollution.

Issue Links

• is part of: HADOOP-7714 Umbrella for usage of native calls to manage OS cache and readahead