perf(controller): measure the presence-aware cap's effect on melo-lap-001 and tune it

[kyle-sexton]

Summary

v0.1.30 enabled the presence-aware cap (#410) on melo-lap-001 with interactiveMaximumConcurrentWorkers: 8 and interactiveIdleThreshold: 10m. Both values are judgment, and #391 never ran its paused-fleet A/B, so neither the per-job hook-latency effect nor the cap's benefit has been measured. Re-measure after about a week of traffic and tune or remove the cap.

Evidence

• perf(controller): fleet job load doubles Claude Code hook latency on dev hosts; v0.1.24 idle controller cost (melo-lap-001) #391 found about 5-7% added Claude Code hook latency per running job after controlling for sessions and activity; its lagged correlation was symmetric, so causation is unproven.
• The perf(controller): fleet job load doubles Claude Code hook latency on dev hosts; v0.1.24 idle controller cost (melo-lap-001) #391 replay estimated a fixed cap of 8 would delay about 19% of jobs (p95 about 3.3 min). The presence cap applies only while the user is at the keyboard, so the real delay should be lower, but it has not been measured.
• host status now reports observed.presence (inputIdleSeconds, interactiveCapActive) and observed.controller cost fields, so the data exists on the host.

Fix

After roughly a week on v0.1.30 (from 2026-09-28):

1. From jobs.json and the worker logs, measure the queue delay added while interactiveCapActive was true against the perf(controller): fleet job load doubles Claude Code hook latency on dev hosts; v0.1.24 idle controller cost (melo-lap-001) #391 replay estimate.
2. From the Claude Code OTEL store (C:\ProgramData\local-otel\cc-store), compare hook latency at 9-12 running jobs (idle periods, cap off) against 8 or fewer (cap on), using perf(controller): fleet job load doubles Claude Code hook latency on dev hosts; v0.1.24 idle controller cost (melo-lap-001) #391's method.
3. Decide: keep 8, move it, or turn the cap off; change hosts/melo-lap-001/ci-runner.yaml in provisioning accordingly.

Verification

A comment on this issue with both measurements and the decision, plus the provisioning PR if the value changes.

Related

• perf(controller): fleet job load doubles Claude Code hook latency on dev hosts; v0.1.24 idle controller cost (melo-lap-001) #391, feat(controller): presence-aware host concurrency cap for interactive dev hosts #410, feat(controller): presence-aware host concurrency cap #412
• melodic-software/provisioning#651

🤖 Generated with Claude Code