Saadi Myftija
002b8458d5
### Problem Firestarter's `didWarmStart: true` means the response was written to a long-poll socket — not that the runner received it. A silently dead poller (no FIN, e.g. a VM torn down mid-poll) leaves the dispatched run stuck in `PENDING_EXECUTING` until the run engine's heartbeat redrive, and each redrive burns a queue redelivery toward `TASK_RUN_DEQUEUED_MAX_RETRIES`. ### Change After a warm-start hit, the supervisor retains the `DequeuedMessage` (TimerWheel, default 10s), then probes the existing `getLatestSnapshot` API. If the run is still on the exact dequeued snapshot, no runner ever acted — it falls through to the regular cold-create path. Recovery: ~10s + cold start, no new APIs, no CLI changes. - **Double-start safe**: `startRunAttempt` runs under a per-run lock and 409s stale snapshot ids, so a reviving runner and the fallback workload can't both execute; the loser exits before running anything. - **Probe errors → do nothing**: healthy runners legitimately act late during platform brownouts (nested attempt-start retries), so falling back on uncertainty would stampede duplicates. The heartbeat redrive stays as the backstop (also covers supervisor restarts dropping timers). - **Off by default**: `TRIGGER_WARM_START_VERIFY_ENABLED` (+ `TRIGGER_WARM_START_VERIFY_DELAY_MS`, 1–60s, default 10s). Disabled = complete no-op. Works for all workload managers (compute/k8s/docker) since it hooks the shared dequeue path. - Emits `warmstart.verify` wide events (`outcome: delivered | fallback | probe_error`), making the silent-loss rate directly measurable.
Server Changes
This directory tracks changes to server-only components (webapp, supervisor, coordinator, etc.) that are not captured by changesets. Changesets only track published npm packages — server changes would otherwise go undocumented.
When to add a file
Server-only PRs: If your PR only changes apps/webapp/, apps/supervisor/, apps/coordinator/, or other server components (and does NOT change anything in packages/), add a .server-changes/ file.
Mixed PRs (both packages and server): Just add a changeset as usual. No .server-changes/ file needed — the changeset covers it.
Package-only PRs: Just add a changeset as usual.
File format
Create a markdown file with a descriptive name:
.server-changes/fix-batch-queue-stalls.md
With this format:
---
area: webapp
type: fix
---
Speed up batch queue processing by removing stalls and fixing retry race
Fields
- area (required):
webapp|supervisor|coordinator|kubernetes-provider|docker-provider - type (required):
feature|fix|improvement|breaking
Description
The body text (below the frontmatter) is a one-line description of the change. Keep it concise — it will appear in release notes.
Writing guidance
These entries are public-facing - they ship verbatim in user-visible release notes. A few rules to keep them clean:
- One sentence is usually enough. The body is the bullet in the changelog. If you need a paragraph, you're probably describing the implementation rather than the change.
- Describe behavior, not implementation. Skip internal scopes, middleware names, library specifics, framework internals. Users care about what's different for them, not how it's wired.
- Never name internal tools or infra. Observability stacks, internal services, infra components, monitoring backends, CI surfaces, AWS specifics - none of these belong in user-facing notes.
Lifecycle
- Engineer adds a
.server-changes/file in their PR - Files accumulate on
mainas PRs merge - The changeset release PR includes these in its summary
- After the release merges, CI cleans up the consumed files
Examples
New feature:
---
area: webapp
type: feature
---
TRQL query language and the Query page
Bug fix:
---
area: webapp
type: fix
---
Fix schedule limit counting for orgs with custom limits
Improvement:
---
area: webapp
type: improvement
---
Use the replica for API auth queries to reduce primary load