## Problem
The item-streaming endpoint of the two-phase batch API (`POST
/api/v3/batches/:batchId/items`) processed streamed items strictly
sequentially. For a batch of many large payloads, each offloaded to
object storage inline, this serialized N object-store round-trips inside
a single request and could exceed Node's default `server.requestTimeout`
(300s). The webapp then returned `408`, which the SDK reads as `408
terminated` and retries up to 5 times, turning a slow ingest into a
failure that takes tens of minutes to surface.
## Fix
Ingest now runs through `p-map` over the NDJSON async iterable with
bounded concurrency (`STREAMING_BATCH_INGEST_CONCURRENCY`, default 10):
- `p-map` pulls lazily from the stream, so at most `concurrency` items
are read and in-flight at once. Peak memory stays bounded to roughly
`concurrency × STREAMING_BATCH_ITEM_MAXIMUM_SIZE` and request-body
backpressure is preserved.
- Set the env to `1` for fully sequential ingestion (escape hatch).
## Why this is safe (ordering and idempotency unchanged)
- Ordering derives from each item's index (enqueue `timestamp =
batch.createdAt + index`), not enqueue order.
- Dedup is atomic per index in `enqueueBatchItem`.
- The NDJSON parser now stamps oversized-item markers with their emit
position, removing the consumer's sequential `lastIndex` assumption (the
only order-dependent bit).
- The count-check and conditional-seal path is untouched.
## Scope
This speeds up every batch ingested through the streaming endpoint, not
just large-payload batches. Each item does a per-item Redis enqueue
regardless of size, and those now overlap. Large payloads benefit most
because they add an object-store offload round-trip on top of the
enqueue.
## Verification
Added an integration test (`streamBatchItems.test.ts`) that drives the
real service against Postgres + Redis + RunEngine and times a 150-item
batch at increasing concurrency. Object-store offload is modelled as a
fixed per-item latency (local round-trips are too small to compare
meaningfully):
```
runCount=150
large payloads (10ms/item offload):
concurrency=1 1739ms
concurrency=10 192ms (9.1x faster)
concurrency=50 57ms (30.7x faster)
small payloads (Redis enqueue only, no offload):
concurrency=1 90ms
concurrency=10 24ms (3.7x faster)
```
The test asserts correctness at every concurrency (all items accepted,
sealed, enqueued exactly once), that parallel ingest beats the
sequential floor, and that the small-payload case is strictly faster
than sequential, so the win is not specific to large payloads.
Also exercised end-to-end over real HTTP against a local server: a
20-item batch (12MB body) ingests and seals, a re-stream of the sealed
batch returns `sealed: true` with zero re-accepted items (idempotent
retry), and an oversized item still seals at its correct index.
Existing coverage stays green: concurrent ingest of a 100-item batch,
in-flight processing never exceeding the configured concurrency,
concurrent dedup on streaming retry, and emit-position marker indexing.
## Follow-ups (not in this PR)
- SDK pre-offload of large item payloads (send `application/store` refs
instead of raw blobs) to remove object-store work from the request hot
path and shrink the request body.
- Optional `server.requestTimeout` bump as a safety net.
## CI fix
Added `.github/workflows/codeql.yml` to replace GitHub's automatic
("dynamic") CodeQL scanning. The dynamic setup was failing to upload
SARIF results because the auto-generated `GITHUB_TOKEN` lacked the
`security-events: write` permission. The explicit workflow grants that
permission at the job level and pins all actions to commit SHAs,
consistent with the repo's security conventions.
## ✅ Checklist
- [ ] I have followed every step in the [contributing
guide](https://github.com/triggerdotdev/trigger.dev/blob/main/CONTRIBUTING.md)
- [ ] The PR title follows the convention.
- [ ] I ran and tested the code works
---
## Testing
- Integration test (`streamBatchItems.test.ts`) validates correctness
and performance at concurrency 1, 10, and 50 for both large and small
payloads.
- End-to-end verified over real HTTP: 20-item/12MB batch ingests and
seals, idempotent retry returns `sealed: true`, oversized item seals at
correct index.
---
## Changelog
Streaming batch ingest now processes items with bounded concurrency
instead of one at a time, so batches of many large payloads ingest far
faster and no longer time out. Concurrency is configurable via
`STREAMING_BATCH_INGEST_CONCURRENCY` (default 10); set it to 1 for fully
sequential ingestion.
---
## Screenshots
_[Screenshots]_
💯
---------
Co-authored-by: Claude Opus 4.8 <noreply@anthropic.com>
Matt Aitken
f48c89752c
