[HDFS-10743] MiniDFSCluster test runtimes can be drastically reduce

• Type: Improvement
• Status: Patch Available
• Priority: Major
• Resolution: Unresolved
• Affects Version/s: 2.0.0-alpha
• Component/s: hdfs
• Target Version/s: 3.5.0
• Assignee: Kuhu Shukla
• Reporter: Daryn Sharp
• Created: 10/Aug/16 16:45
• Updated: 04/Jan/24 07:48

Description

MiniDFSCluster tests have excessive runtimes. The main problem appears to be the heartbeat interval. The NN may have to wait up to 3s (default value) for all DNs to heartbeat, triggering registration, so NN can go active. Tests that repeatedly restart the NN are severely affected.

Example for varying heartbeat intervals for TestFSImageWithAcl:

• 3s = ~70s – (disgusting, why I investigated)
• 1s = ~27s
• 500ms = ~17s – (had to hack DNConf for millisecond precision)

That a 4x improvement in runtime.

17s is still excessively long for what the test does. Further areas to explore when running tests:

• Reduce numerous sleeps intervals in DN's BPServiceActor.
• Ensure heartbeats and initial BR are sent immediately upon (re)registration.