Investigate frequently triggered alert "0+ rate of growth of update queue length over 5 minutes for 2h0m0s"

Created by: indradhanush

The alert has started getting triggered for the last few days. And although processing of sync jobs appears to remain unaffected, we need to dig into the root cause of this.

• Add debug logs for resetting counter #30103
• Feature flag jitter in repo update interval #30154