A Lambda function consumes an SQS queue.
Limit concurrent invocations so that connections to a downstream database remain within capacity.
Which setting is most appropriate?
Set Maximum concurrency on the event source mapping to cap SQS-triggered Lambda concurrency.
Detailed explanation
DNS TTL does not change the number of parallel event-source invocations.
DNS TTL does not change the number of parallel event-source invocations.
The event-source limit caps concurrent SQS-triggered invocations and protects the downstream database.
The event-source limit caps concurrent SQS-triggered invocations and protects the downstream database.
Immediate timeouts cause failures and do not control event-source parallelism.
Immediate timeouts cause failures and do not control event-source parallelism.
S3 object lifecycle management does not control Lambda event-source concurrency.
S3 object lifecycle management does not control Lambda event-source concurrency.
Check official documentation
Compare the following points with the official documentation.
Lambda event source mapping maximum concurrencyの公式説明を確認する。
What to confirm
関数全体の同時実行とイベントソース単位の並列度を区別できる。
Key points
- Event source mapping
- Maximum concurrency
- SQS-Lambda
Notes
- Environment: AWS公式SOA-C03試験ガイドとAWS公式ドキュメントの確認
- Confirm current AWS service behavior in the official documentation.
Foundation review
Boundary-specific control
Event-source concurrency protects one source without necessarily limiting every invocation path.
Back-pressure
A bound on parallel work prevents queue-driven bursts from overwhelming a dependency.