I'm considering to use step functions for scenarios like retrieving data from a few sources, composing a mail with it and sending that mail - with appropriate retries. The step function is triggered from API Gateway, so by calling "StartExecution".
It works great, but I notice that the soft limit for StartExecution is set to 2 executions/second, with a bucket size of 100. I'm expecting tens or maybe hundreds of requests per second...
Am I right to understand that every call to the API counts towards that Start Execution soft limit? Does this low default limit indicate that Step Functions may not be the right tool for the job?
Eventually I contacted AWS Support, asking
Can we assume that a future Service Limit request to increase the bucket or refill size, e.g. first to 100 executions/second, later to maybe 500 executions/second, will be fulfilled? Would there be any concerns?
The answer:
Yes we do support 500 executions/s, however since the load profile of different types of executions vary so widely it's hard to be specific about this customers executions. Furthermore, as Step Functions grows and each customer has less impact on the larger service it will be easier to increase limits.
So we're good :)