[HDFS-4486] Add log category for long-running DFSClient notices

• Type: Improvement
• Status: Closed
• Priority: Minor
• Resolution: Fixed
• Fix Version/s: 2.6.0
• Assignee: Zhe Zhang
• Reporter: Todd Lipcon
• Created: 08/Feb/13 21:56
• Updated: 01/Dec/14 03:07
• Resolved: 27/Aug/14 20:45

Description

There are a number of features in the DFS client which are transparent but can make a fairly big difference for performance – two in particular are short circuit reads and native checksumming. Because we don't want log spew for clients like "hadoop fs -cat" we currently log only at DEBUG level when these features are disabled. This makes it difficult to troubleshoot/verify for long-running perf-sensitive clients like HBase.

One simple solution is to add a new log category - eg o.a.h.h.DFSClient.PerformanceAdvisory - which long-running clients could enable at DEBUG level without getting the full debug spew.