[MAPREDUCE-2340] optimize JobInProgress.initTasks()

• Type: Improvement
• Status: Patch Available
• Priority: Major
• Resolution: Unresolved
• Affects Version/s: 0.20.1, 0.21.0
• Component/s: jobtracker
• Labels: BB2015-05-TBR critical-0.22.0
• Target Version/s: 0.22.0, 1.3.0
• Assignee: Unassigned
• Reporter: Kang Xiao
• Created: 21/Feb/11 04:56
• Updated: 08/May/15 19:16

Description

JobTracker's hostnameToNodeMap cache can speed up JobInProgress.initTasks() and JobInProgress.createCache() significantly. A test for 1 job with 100000 maps on a 2400 cluster shows nearly 10 and 50 times speed up for initTasks() and createCache().