When a paused DBQuery resumes, it opens a fresh read transaction and reconstructs the cursor from a saved levId checkpoint. If writes landed during the pause, the B-tree page layout will have changed, forcing a cold cursor seek rather than continuing a warm one.
Under high write concurrency with many subscriptions resuming simultaneously, this could produce a measurable latency spike.
Plan:
Stress with benchmarking harness at high EVENT + REQ concurrency
Capture per-thread flamegraphs during write bursts
Correlate p99 latency spikes with cursor resume timing
Are you working on it?
Yes
When a paused DBQuery resumes, it opens a fresh read transaction and reconstructs the cursor from a saved levId checkpoint. If writes landed during the pause, the B-tree page layout will have changed, forcing a cold cursor seek rather than continuing a warm one.
Under high write concurrency with many subscriptions resuming simultaneously, this could produce a measurable latency spike.
Plan:
Stress with benchmarking harness at high EVENT + REQ concurrency
Capture per-thread flamegraphs during write bursts
Correlate p99 latency spikes with cursor resume timing
Are you working on it?
Yes