[HDDS-2449] Delete block command should use a thread pool

• Type: Improvement
• Status: Resolved
• Priority: Major
• Resolution: Duplicate
• Affects Version/s: 1.0.0
• Component/s: Ozone Datanode
• Labels: TriagePending
• Target Version/s: 1.4.0
• Assignee: Stephen O'Donnell
• Reporter: Stephen O'Donnell
• Created: 08/Nov/19 15:16
• Updated: 21/Dec/22 09:44
• Resolved: 21/Dec/22 09:44

Description

The datanode receives commands over the heartbeat and queues all commands on a single queue in StateContext.commandQueue. Inside DatanodeStateMachine a single thread is used to process this queue (started by initCommandHander thread) and it passes each command to a ‘handler’. Each command type has its own handler.

The delete block command immediately executes the command on the thread used to process the command queue. Therefore if the delete is slow for some reason (it must access disk, so this is possible) it could cause other commands to backup.

This should be changed to use a threadpool to queue the deleteBlock command, in a similar way to ReplicateContainerCommand.

Issue Links

• duplicates: HDDS-5360 DN failed to process all delete block commands in one heartbeat interval