What is the maximum number of event source mappings per AWS Lambda?

Viewed 5421

I cannot find this limitation listed anywhere in the AWS Documentation for maximum number of event sources to trigger one Lambda.

I have a Lambda which will be triggered by an indefinitely growing number of S3 Buckets. Obviously this will only work if the maximum number of buckets exceeds the maximum number of triggers. Is there a maximium? If so, what is it, and can it be increased?

3 Answers

I just ran into a limit. I added 60 CloudWatch triggers to a Lambda function and when I tried adding one more trigger, I got an error saying:

"The final policy size (20643) is bigger than the limit (20480). (Service: AWSLambda; Status Code: 400; Error Code: PolicyLengthExceededException;"

This is still very high in search results, which led me here. I was able to create 6500 event source mappings for an MQ Event Source. The Web Console maxes out at 1000 displayed event source mappings. I did not verify that all 6500 event source mappings worked.

Related