[HDFS-4182] SecondaryNameNode leaks NameCache entries

• Type: Bug
• Status: Closed
• Priority: Critical
• Resolution: Fixed
• Affects Version/s: 0.23.4, 2.0.2-alpha, 3.0.0-alpha1
• Fix Version/s: 2.0.3-alpha, 0.23.5
• Component/s: namenode
• Target Version/s: 2.0.3-alpha, 0.23.5
• Assignee: Robert Joseph Evans
• Reporter: Todd Lipcon
• Created: 12/Nov/12 22:16
• Updated: 12/May/16 18:11
• Resolved: 14/Nov/12 22:20

Description

We recently saw an issue where a 2NN ran out of memory, even though it had a relatively small fsimage. When we looked at the heap dump, we saw that all of the memory had gone to entries in the NameCache.

It appears that the NameCache is staying in "initializing" mode forever, and therefore a long running 2NN leaks entries.