[HDFS-7603] The background replication queue initialization may not let others run

• Type: Bug
• Status: Closed
• Priority: Critical
• Resolution: Fixed
• Fix Version/s: 2.7.0
• Component/s: rolling upgrades
• Target Version/s: 2.7.0
• Hadoop Flags: Reviewed
• Assignee: Kihwal Lee
• Reporter: Kihwal Lee
• Created: 12/Jan/15 16:43
• Updated: 10/Apr/15 20:30
• Resolved: 29/Jan/15 18:38

Description

The background replication queue initialization processes configured number of blocks at a time and releases the namesystem write lock. This was to let namenode start serving right after a standby to active transition or leaving safe mode. However, this does not allow others to run much if the lock fairness is set to "unfair" for the higher throughput.

I propose adding a delay between unlocking and locking in the async repl queue init thread.