Files
hyperframes/examples/aws-lambda
Miguel Ángel 2a14cbc924 perf(aws-lambda): size distributed renders from account concurrency limits (#5813)
* perf(aws-lambda): run chunks through a Distributed Map to lift the 40-chunk cap

The inline Map runs at most 40 chunk renders at once. Both state machine
definitions (CDK and SAM) now use a Distributed Map with STANDARD child
executions, capped at the function's reserved concurrency so chunks past it
queue instead of being throttled. Progress reads each chunk's child
execution history so frames, cost and chunk errors still show up.

* fix(aws-lambda): retry Lambda throttles for minutes and stop on oversized chunks

A throttled task used to burn its four catch-all retries in about 30 s.
It now gets its own jittered backoff of several minutes, because another
render on the same function can still hold the reserved slots. Plan
treats CHUNK_EXCEEDS_WORKER_TIMEOUT as terminal in both definitions.

* chore(aws-lambda): trim stack comments to keep the comment share flat

* fix(aws-lambda): keep render --wait working at hundreds of chunks

Progress polls read the chunk Map Run's counts (one DescribeMapRun) instead of
every child execution's history, take exact chunk frames and cost from the Map
output once it exits, and read failed children only when the counts show a
failure. The SDK client retries throttled calls up to 8 times with backoff.

* feat(aws-lambda): size each render's concurrency to the account instead of a fixed 8

* fix(lambda): keep the concurrency SDK external in published modules

* fix(cli): keep an existing stack's reserved concurrency on redeploy

Redeploying without --concurrency sent ReservedConcurrency=-1, which
removed the cap of 8 that earlier CLI versions reserved by default and
stopped recording it in the state file. The override is now left out
when the flag is omitted, so SAM keeps the stack's current value (a new
stack still gets the template's unreserved default). The state file
records the deployed value, and deploy prints the kept reservation.

* fix(aws-lambda): keep progress working for callers without DescribeMapRun

Callers whose IAM policy came from an earlier `lambda policies user`
lack states:DescribeMapRun, so reading a running Distributed Map threw
AccessDeniedException out of `lambda progress` and `render --wait`
while the render itself went on to succeed. getRenderProgress now
catches only that error around the map-run read, returns the parent
snapshot (status, plan and assemble progress) and adds a warning to
re-apply the policy, which both commands print. Other errors still
throw.

* fix(cli): let the documented deploy policy drop a reserved concurrency

When a redeploy removes a function's reserved concurrency, CloudFormation
calls lambda:DeleteFunctionConcurrency. The policy printed by
`lambda policies role|user` granted only PutFunctionConcurrency, so the
update failed and rolled back. Grant it, and pin it with
states:DescribeMapRun in the required-actions test.

* fix(aws-lambda): read smoke chunk hashes from the Distributed Map output

With chunks in a Distributed Map, their task results live in child
executions, so the smoke gate's chunk-hash check found 0 chunks in the
parent history and failed every v1/v2 comparison. Read Chunks[] from the
RenderChunks / RenderChunksV2 MapStateExited output instead, as
getRenderProgress does. The stack this script deploys only has the
Distributed Map, so the inline-Map path is gone.

* fix(producer): cap a pinned chunk size at the worker concurrency, not 16

With --chunk-size or --target-chunk-frames and no --max-parallel-chunks,
the plan still capped the render at 16 chunks however many workers the
account allowed, so --chunk-size 30 on a 60 s render gave 16 chunks of
113 frames. The cap is now one wave across the worker concurrency, as
the --max-parallel-chunks docs say; 16 remains when the concurrency is
unknown.

* feat(cli): remove a stack's reserved concurrency with --concurrency=none

Since an omitted --concurrency now keeps the stack's reservation, there
was no CLI way back to the unreserved default. --concurrency=none sends
ReservedConcurrency=-1, the state file records the stack as unreserved
and deploy says the reservation was removed. Positive N and an omitted
flag behave as before; any other value is rejected instead of being
silently ignored.

* chore(aws-lambda): raise the package size budget for account-sized concurrency

Measured with pnpm@10.17.1 pack after rebasing on main with the S3 assembly change: 67,763 packed / 244,685 unpacked; the budget is the check's own 5% headroom over that.
2026-10-19 00:57:30 +00:00
..

AWS Lambda + Step Functions deployment

Reference SAM template for deploying HyperFrames distributed rendering on AWS. One Lambda function, three roles (Plan / RenderChunk / Assemble), choreographed by a Step Functions standard workflow with a Map state for parallel chunk rendering.

See packages/aws-lambda/README.md for the Lambda handler architecture.

Prerequisites

  • AWS account with IAM permissions to deploy CloudFormation stacks containing Lambda, Step Functions, S3, IAM, and CloudWatch resources.
  • sam CLI installed (≥ 1.100).
  • bun installed (≥ 1.3) to build the handler ZIP.

One-shot deploy

# 1. Build the handler ZIP that `template.yaml`'s CodeUri points at.
bun install                                       # at repo root
bun run --cwd packages/aws-lambda build:zip

# 2. Deploy. First time: `--guided` to set stack name + region.
cd examples/aws-lambda
sam deploy --guided --resolve-s3

--resolve-s3 lets SAM pick (or create) a per-account bucket to host the uploaded ZIP. After the first deploy, subsequent updates can omit --guided and --resolve-s3 — SAM remembers your choices in samconfig.toml.

What gets created

Resource Purpose
Render Lambda Single function, handler handler.handler. Dispatches on event.Action.
Render State Machine Step Functions standard workflow. Plan → Map(N) RenderChunk → Assemble.
Render Bucket S3 bucket for plan tarballs, chunk outputs, and final mp4. renders/ prefix expires after 7 days.
IAM role for the state machine Invokes the Lambda; writes CloudWatch logs; X-Ray traces.
IAM role for the Lambda (managed by SAM) S3 CRUD on the render bucket; CloudWatch logs.
Runaway-invocation alarm Fires if RenderChunk runs more than ChunkInvocationAlarmThreshold times in an hour.

Running a render

Upload your project as a zip to the render bucket, then start a Step Functions execution:

STACK_NAME=hyperframes-render          # whatever you picked at deploy
RENDER_BUCKET=$(aws cloudformation describe-stacks \
  --stack-name "$STACK_NAME" \
  --query 'Stacks[0].Outputs[?OutputKey==`RenderBucketName`].OutputValue' \
  --output text)
STATE_MACHINE_ARN=$(aws cloudformation describe-stacks \
  --stack-name "$STACK_NAME" \
  --query 'Stacks[0].Outputs[?OutputKey==`RenderStateMachineArn`].OutputValue' \
  --output text)

# Tar + upload the project directory. The handler uses `tar` (not
# `unzip`, which Lambda's base image doesn't ship), so the on-the-wire
# archive format is `.tar.gz`.
tar -czf my-project.tar.gz -C ./my-project .
aws s3 cp my-project.tar.gz "s3://${RENDER_BUCKET}/projects/my-project.tar.gz"

# Start the execution. The input JSON tells the state machine where to
# read inputs and write outputs.
aws stepfunctions start-execution \
  --state-machine-arn "$STATE_MACHINE_ARN" \
  --input "$(cat <<EOF
{
  "ProjectS3Uri": "s3://${RENDER_BUCKET}/projects/my-project.tar.gz",
  "PlanOutputS3Prefix": "s3://${RENDER_BUCKET}/renders/$(date +%s)/",
  "OutputS3Uri": "s3://${RENDER_BUCKET}/output.mp4",
  "Config": {
    "fps": 30,
    "width": 1920,
    "height": 1080,
    "format": "mp4",
    "chunkSize": 240,
    "maxParallelChunks": 8,
    "runtimeCap": "lambda"
  }
}
EOF
)"

The Step Functions execution kicks off Plan, fans out RenderChunk via the Map state, and finally Assemble. Final mp4 lands at OutputS3Uri. Plan v2 is the default when PlanProtocol is absent. V2 uses separate manifest and content-addressed artifact locators throughout the workflow and never places a v2 object in PlanS3Uri. The deprecated v1 transport remains available by sending "PlanProtocol": "v1" explicitly.

Upgrading an existing stack

Pause new renders and let active Step Functions executions drain before the upgrade. Redeploy the Lambda handler and this state machine (or the matching CDK construct) from the same package version before upgrading the application that calls renderToLambda. The new SDK sends explicit v2 by default, while older infrastructure may default omission to v1 or lack v2 support. Keep passing planProtocol: "v1" until the infrastructure redeploy completes if you need a staged migration.

Local invocation

You can test the Lambda handler without deploying anything via SAM local:

# Build the ZIP first.
bun run --cwd packages/aws-lambda build:zip

# Launch a local Lambda runtime emulator and run a sample plan event.
cd examples/aws-lambda
sam validate
sam local invoke RenderFunction --event sample-events/plan.json

The sample-events/ directory ships three tiers for each action: *.json demonstrates default v2 with PlanProtocol omitted, *-v1.json demonstrates deprecated explicit-v1 compatibility, and *-v2.json demonstrates callers that stamp v2 explicitly. They reference fake S3 URIs — useful for sanity-checking the handler's dispatch logic; not for full end-to-end testing (real S3 calls require credentials and a project zip to actually exist).

End-to-end smoke + benchmark

For full end-to-end validation against real AWS — the gate that proves the architecture works on a deployed Lambda — use the local smoke script:

# Defaults use Plan v2 and the fixture's meta.json minPsnr (30 dB for mp4-h264-sdr).
./scripts/smoke.sh

# Customised:
./scripts/smoke.sh \
  --fixture mp4-h264-sdr \
  --chunk-counts 2,4,8,16 \
  --plan-protocol both \
  --psnr-threshold 40 \
  --reserved-concurrency 8

# Keep the stack alive for inspection afterward:
./scripts/smoke.sh --keep-stack

# Show all flags including cost notes:
./scripts/smoke.sh --help

The script builds the handler ZIP, deploys this template under a per-run stack name, renders the fixture at each chunk count via the Step Functions state machine, PSNR-compares against the in-process baseline (which is git-LFS tracked under packages/producer/tests/distributed/<fixture>/output/), captures per-execution Step Functions history, and tears the stack down. Use --plan-protocol both to run v1 and v2 through the same deployed Lambda package and baseline. Each v1/v2 pair is also gated directly on per-chunk hashes from Step Functions history, normalized decoded RGBA frame hashes, decoded 48 kHz stereo s16le PCM hashes and byte counts, normalized stream metadata, and duration. Encoded MP4 SHA equality is reported but is informational unless --require-encoded-sha-equal is set. The script assigns unique function/state-machine names, uses a dedicated temporary SAM artifact bucket, and removes render objects, retained buckets, the implicit Lambda log group, and deployment artifacts on teardown. Suspended-version buckets are purged in 1,000-entry batches, including concrete versions, null versions, and delete markers. It then verifies that the stack, both buckets, Lambda, state-machine, and both log groups are absent; an otherwise-successful run fails if cleanup cannot be proven.

Wall-clock methodology caveat (eval.sh only). eval.sh reports a local-vs-Lambda "speedup" column. The local timing includes bun + tsx + harness scaffolding (not just renderer-internal time); the Lambda timing measures Step Functions execution only. This biases the speedup against Lambda on tiny fixtures and in favour of Lambda on larger ones. Treat the number as "end-to-end CLI experience," not as a renderer-vs-renderer benchmark. Cold-start variance is ±5-10s per chunk; run with --iterations 3+ to report medians.

Cost per pass. Each eval.sh invocation runs SAM deploy (~$0.01 in CFN operations) plus N fixtures × ITERATIONS × CHUNK_COUNT Lambda invocations at MemorySize (default 10 GiB) × per-chunk wall clock. With defaults (4 fixtures, 1 iteration, chunk-count 4) the Lambda spend is roughly $0.10-$0.20 per pass before S3 transfer. Lower --reserved-concurrency for cost-conscious accounts; higher --iterations improves median stability at proportional cost.

Outputs land under <repo-root>/lambda-smoke-artifacts/:

  • results.json — planProtocol × chunkCount × wallClockMs × psnrAvgDb
  • semantic-comparisons.json — direct v1/v2 semantic gate results
  • renders/<protocol>-N<N>-output.mp4 — each rendered variant
  • renders/<protocol>-N<N>-history.json — full Step Functions execution history
  • renders/v1-v2-N<N>.* — normalized frame hashes, ffprobe metadata, and comparison JSON

Prerequisites: aws (v2), sam (≥ 1.100), bun (≥ 1.3), ffmpeg, jq, zip. AWS credentials come from the standard resolution chain (env vars → ~/.aws/credentials → SSO → IMDS). Pin a specific profile with --profile <name> or AWS_PROFILE=<name>.

Parameters

Parameter Default Notes
ProjectName hyperframes Prefix for created resource names.
LambdaMemoryMb 10240 Lambda memory; Lambda allocates CPU proportionally. 10 GB recommended for 1080p.
LambdaTimeoutSec 900 Per-invocation timeout. 15 min is Lambda's hard ceiling.
ReservedConcurrency -1 Hard cap on simultaneous Lambda invocations. -1 = unreserved. Set to e.g. 50 to bound cost.
ChromeSource sparticuz Must match the --source= flag passed to build-zip.ts.
ChunkInvocationAlarmThreshold 1000 CloudWatch alarm threshold (RenderChunk invocations per hour).

Cleanup

sam delete --stack-name hyperframes-render

S3 buckets are Retained on delete to protect rendered artifacts. Empty + delete the bucket manually after sam delete if you want to fully tear down.

Cost model

Service Driver Approximate cost
Lambda Per-invocation billed duration × memory ≈ $0.0000167/GB-s; a 10 GB function running 5 min costs ~$0.50
Step Functions Standard Per state transition $0.025/1k transitions
S3 Storage + GET/PUT Dominated by mp4 storage; plan tarballs expire in 7 days
CloudWatch Logs Ingestion + storage Logs are not throttled; set retention manually if cost matters

A 60-second 1080p30 composition at default chunkSize=240 (8 chunks) typically costs ~$0.04 in Lambda time + ~$0.001 in Step Functions. The eval script under scripts/eval.sh produces real per-fixture cost numbers when you run it against your own AWS account.

Troubleshooting

  • "Chrome failed to launch" — the ZIP was likely built with the wrong --source. Match ChromeSource to the build flag.
  • "PLAN_HASH_MISMATCH" — non-retryable. The plan tarball was written by a different version of the producer than the chunk worker is running. Re-plan from scratch.
  • "BROWSER_GPU_NOT_SOFTWARE" — Chromium fell back to a hardware GL backend. Should not happen in Lambda (no GPU); file an issue.
  • CloudWatch alarm firing on runaway-chunk-invocations — check the state machine execution history for an unintended Map fan-out, or raise the threshold if your workload genuinely exceeds it.

What's NOT in this directory

  • CDK construct shipping the same topology programmatically — follow-up.
  • hyperframes lambda deploy / render / progress / destroy CLI — follow-up.
  • Migration guide — follow-up.
  • Lambda RIE local smoke harness mode — follow-up.