fix(lifecycle): raise axum body limit to 6 MB for large Lambda payloads#1044
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fix(lifecycle): raise axum body limit to 6 MB for large Lambda payloads#1044litianningdatadog wants to merge 2 commits intomainfrom
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axum 0.7+ applies a 2 MB default body limit globally, causing the /lambda/start-invocation endpoint to reject payloads larger than 2 MB with "length limit exceeded". Raises the limit to 6 MB to match Lambda's maximum synchronous invocation payload size. Fixes #1041
duncanista
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Feb 24, 2026
duncanista
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Feb 26, 2026
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| // Lambda's maximum synchronous invocation payload size | ||
| // reference: https://docs.aws.amazon.com/lambda/latest/api/API_Invoke.html | ||
| const LAMBDA_INVOCATION_MAX_PAYLOAD: usize = 6 * 1024 * 1024; |
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Wondering how would this look like with streaming lambda payload... do we have guards to not send the payload if it goes over the limit?
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Because in streaming the max is 200MB
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I mean good for now, but we might want to leave a comment about streaming
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https://datadoghq.atlassian.net/browse/SVLS-8609
Issue reported: #1041
Summary
/lambda/start-invocationendpoint was rejecting payloads larger than 2 MB withlength limit exceededDefaultBodyLimit::max(6 * 1024 * 1024)) to match Lambda's maximum synchronous invocation payload sizeTest plan
bash local_tests/repro-large-payload.shwhich sets up the local test env and sends a 3 MB payload to/lambda/start-invocationand verifies HTTP 200 with nolength limit exceedederror{"level":"ERROR","message":"DD_EXTENSION | ERROR | Failed to extract request body: Failed to buffer the request body: length limit exceeded"}{"level":"DEBUG","message":"DD_EXTENSION | DEBUG | Received start invocation request from headers:{\"datadog-meta-lang\": \"java\", \"user-agent\": \"curl/8.3.0\", \"host\": \"localhost:8124\", \"lambda-runtime-aws-request-id\": \"test-large-payload-request\", \"expect\": \"100-continue\", \"accept\": \"*/*\", \"content-length\": \"3200074\", \"content-type\": \"application/json\"}"}