I am not aware of a limit on concurrent temporary credentials for any usage. You can refresh credentials as often as you want (which generates new credentials). A temporary credential is valid (settable) from 900 seconds to 12 hours. Typical refresh logic will refresh at 50% of time or a set value such as 5 minutes. The correct value depends on the service - S3 put needs a longer time than an EC2 instance listing.
The only limitation that I am aware of is API rate limiting (i.e. API calls per second). For this, the error is ThrottlingException
/ HTTP Status Code 400.
If you do hit ThrottlingException
then implement expotential backoff
and try again.
Error Retries and Exponential Backoff in AWS