## Summary
Speeds up webapp test jobs by balancing measured work across runners,
reducing repeated container setup, and ensuring test workers release
shutdown resources promptly. Unit tests run across 24 duration-aware
shards, while E2E tests run across two balanced shards.
## Design
`RunEngine` shutdown now closes processing resources before support
resources, continues cleanup if one close fails, and reuses one shutdown
promise for concurrent callers. Redis workers clear completed shutdown
deadlines so finished tests no longer wait on idle timers.
Container-heavy suites are split only where it improves parallelism, and
repeated replication and engine fixtures are consolidated where one
end-to-end case provides coverage. Timing weights are refreshed for all
affected files.
Dependency installation overlaps container pulls, and both workflows use
WarpBuild's Node setup action.
The SDK discovers an external deployment id at runtime (explicit
TRIGGER_EXTERNAL_DEPLOYMENT_ID always; platform commit-SHA variables and
generic fallbacks when TRIGGER_AUTOMATIC_SKEW_VERSION_PROTECTION=1) and
sends it alongside lockToVersion; the server resolves precedence
(version > external id > current). An id held by a deployed deployment
pins the run to that worker; an in-flight or unknown id parks the run in
PENDING_VERSION with the id in TaskRun.annotations, wakes it pinned when
a deployment carrying the id finalizes (ClickHouse candidates, Postgres
authoritative), and expires it after a deadline that re-checks Postgres
before acting. Parking outranks delaying and preserves delayUntil. The
id is projected to ClickHouse task_runs_v2.external_deployment_id during
replication. Redis cache for id-to-worker resolution, guarded
version-aware writes.
Ids are not unique. Several deployments can hold one id - a --force
rebuild is the ordinary way to get there - so resolution always picks
the highest version among the candidates, never the newest by timestamp.
The rule is applied identically on both paths that can bind a run to a
worker: resolveExternalDeployment at trigger time, and
PendingVersionSystem when a landing deployment wakes a parked run.
Version comparison is numeric on the counter half, so 20260807.10
outranks 20260807.9.
A run whose id never lands expires at the deadline with
EXTERNAL_DEPLOYMENT_NOT_FOUND and an error naming the id it waited for,
which is what a failed build or a typo looks like from the caller.
Default deadline is one hour (EXTERNAL_DEPLOYMENT_PARK_DEADLINE_MS).
Debounce registration happens in both the parked and the delayed branch
through one helper, so a debounced run that parks still binds its
debounce key; without it every later trigger for the same key created
another parked run, and all of them executed when the deployment landed.
The two DELAYED-only status checks in DebounceSystem also accept
PENDING_VERSION, without which the lock-contention fallback would
rethrow a 5xx the SDK retries and amplifies, and the fast path would
push every trigger on a parked key through the redlock.
Resolution is skipped in development. A dev environment cannot hold a
WorkerDeployment - trigger dev registers a BackgroundWorker with nothing
behind it, and deploy --env refuses dev - so an external deployment id
there could only ever park, and the parked run then expired against the
dev TTL while a connected dev worker sat idle. The id is still annotated
so the dashboard shows what the app sent (TRI-13000).
Chris Arderne