## Summary Three issues in one PR. Implements Cache-Augmented Generation (CAG) support in the api-gw. --- ### #44 — Memory ServiceAdapter: standing-context resource - Code-registers `memory` adapter with `standing-context` resource (`POST /memory/standing-context`) - Fixes dispatcher bug: method-level `Auth.Capability` override now respected (was always using verb-derived capability) - Auth: `memory:read` required via method-level override; `memory:write` for ingest - `MEMORY_UPSTREAM_URL` env configures upstream ### #45 — Continuous batching: warmup deprioritisation + per-backend semaphore - In-memory bounded queue per backend: `VLLM_MAX_QUEUE_DEPTH` slots (default 20) - Concurrency limiter: `VLLM_MAX_NUM_SEQS` slots (default 4) - `X-Poimen-Warmup: true` → sleep `WARMUP_DELAY_MS` (default 500ms) before queue entry, strip header, add `X-Priority: low` - Queue full → 503 immediately, no goroutine pile-up - Metrics: `warmup_requests_delayed_total`, `queue_full_requests_total` at `/metrics` ### #46 — Cache-aware routing: rendezvous hash + prefix cache hit logging - `addresses: [...]` YAML field for multi-backend models (backward-compat with `address`) - `X-Poimen-Cache-Key` header → rendezvous-hash backend selection (same key = same GPU) - No cache key → round-robin - Failed backend excluded 30s; next-highest-score fallback - `vllm-num-cached-tokens` response header captured → `vllm_prefix_cache_hit_tokens_total` counter + structured log --- ## Verification ``` go build ./... ✅ go vet ./... ✅ go test -race ./... ✅ (all packages, 0 races) ``` ## Reviewer verdicts - reviewer-sre: SIGN-OFF - reviewer-quality: SIGN-OFF ## Non-blocking findings (🟡🔵 only) - `getOrCreateTransport` not goroutine-safe by design; pre-population invariant documented - `time.Sleep(warmupDelay)` holds goroutine; context-cancel alternative left as TODO - OTel trace_id not propagated into CAG log events (existing gap) Closes #44 Closes #45 Closes #46 --------- Co-authored-by: Admin Bot <[email protected]> Reviewed-on: #47
Time-to-First-Token (TTFT) and Inter-Token Latency (ITL) metrics for LLM inference observability Metrics: llm_ttft_seconds, llm_itl_seconds, llm_tokens_total Closes #31 #32 #33 --------- Co-authored-by: poimen <[email protected]> Reviewed-on: #28