ilkerandClaude Opus 5
dc38dd6096
CI / test (push) Successful in 48s
Inserted between quota checks and scheduling: admission answers when a request may proceed, the scheduler still answers where it goes. Keeping them apart is the point — an engine queue is FIFO and knows nothing about tenants, so once a batch job is in it, no endpoint selection rescues the request behind it. - saturation detector: one number per pool, the worse of queue depth and KV occupancy, since either alone misleads. - priority bands with per-band saturation ceilings, so the cluster degrades from the bottom up. - tenant round-robin within a band: one caller sending a thousand requests takes one slot in the rotation, not a thousand. - bounded queues with capacity (503) and TTL (504); cancelled requests leave the queue instead of holding capacity. - metrics for queue depth, wait time, rejections and pool saturation. Exit criterion, measured in test/e2e: with 500 concurrent bronze requests running continuously, interactive p99 in the platinum band stays at 1.04-1.24x idle against a 1.5x budget. With admission off the same load pushes it to 55-60x. Both directions are asserted, so the test fails if admission regresses and also if the load generator stops being a real load. Two lags had to be closed, and they needed different answers. Engine metrics are scraped and lag an interval; router inflight does not, but it counts running requests, and treating those as queue makes a healthy engine look overloaded every interval. What is actually queued is inflight minus batch capacity, and capacity is not in the metric contract, so it is learned as the high-water mark of observed running. Separately, between admission granting a request and the router dispatching it the request is invisible everywhere, so a simultaneous burst passed the check en masse; the controller now counts its own outstanding leases against dispatched inflight. One plan correction: a saturation ceiling of 1.0 was documented as "never held back". It is not — it means "flow up to the healthy limit". A band that must never wait needs a ceiling above 1. Plan §7.2.2 updated. Co-Authored-By: Claude Opus 5 (1M context) <noreply@anthropic.com>