[KAFKA-5741] Prioritize threads in Connect distributed worker process

• Type: Improvement
• Status: Resolved
• Priority: Critical
• Resolution: Won't Fix
• Affects Version/s: 0.11.0.0
• Component/s: connect
• Assignee: Unassigned
• Reporter: Randall Hauch
• Created: 16/Aug/17 17:17
• Updated: 15/Oct/19 16:14
• Resolved: 15/Oct/19 16:14

Description

Connect's distributed worker process uses the DistributedHerder to perform all administrative operations, including: starting, stopping, pausing, resuming, reconfiguring connectors; rebalancing; etc. The DistributedHerder uses a single threaded executor service to do all this work and to do it sequentially. If this thread gets preempted for any reason (e.g., connector tasks are bogging down the process, DoS, etc.), then the herder's membership in the group may be dropped, causing a rebalance.

This herder thread should be run at a much higher priority than all of the other threads in the system.