What is the best solution for Lamba concurrent invocation causing ACM rate exceeded error

Hi,

the usual way to reduce recurring API calls fetching same value is to use Lambda caching: initial call will be re-used multiple times across Lambda invocations and should suppress the "ACM rate exceeded" rate error

See this post to understand how to implement it efficiently: https://aws.amazon.com/blogs/compute/caching-data-and-configuration-settings-with-aws-lambda-extensions/

Best,

Didier

You can try and increase the ACM API limit.

Another option is to read the certificate only once per each function, outside the handler. This way future invocations of the same function, will reuse the certificate.