[HDFS-17019] Optimize the logic for reconfigure slow peer enable for Namenode

• Type: Bug
• Status: Resolved
• Priority: Major
• Resolution: Fixed
• Affects Version/s: 3.4.0
• Fix Version/s: 3.4.0
• Component/s: namanode
• Labels: pull-request-available
• Target Version/s: 3.4.0
• Hadoop Flags: Reviewed
• Assignee: Haiyang Hu
• Reporter: Haiyang Hu
• Created: 18/May/23 10:44
• Updated: 28/Jan/24 02:16
• Resolved: 08/Jun/23 02:10

Description

The logic of Reconfigure slow peer enable for Namenode requires the following optimizations:

1.Make SlowPeerTracker slowPeerTracker volatile.

2.When starting the NameNode, if the parameter dfs.datanode.peer.stats.enabled is set to false, DatanodeManager#startSlowPeerCollector() will not call, as a result the Slow peers collection thread 'slowPeerCollectorDaemon' will not be started .

If the parameter dfs.datanode.peer.stats.enabled is dynamically refreshed to true, the current logic will not call DatanodeManager#startSlowPeerCollector(), which to thread 'slowPeerCollectorDaemon' not started as expected, so we will optimize here

Issue Links

• is related to: HDFS-16528 Reconfigure slow peer enable for Namenode
• links to: GitHub Pull Request #5671