What happens if the number of API calls for a SQS fifo queue exceeds the quota?

Question

The document says:
> Without batching, FIFO queues support up to 300 API calls per second, per API method (SendMessage, ReceiveMessage, or DeleteMessage).

https://docs.aws.amazon.com/AWSSimpleQueueService/latest/SQSDeveloperGuide/quotas-messages.html

- What happens if I call the API at a higher rate than 300 calls per second?
  - Do I get any exceptions in the client side?
  - Are those messages sent while the limit is reached gonna be ignored, or do they just wait to be processed until the next time window?

Answer

The client trying to send the messages will get an error and it is up to the client to retry. If the client doesn't retry the message, it will be ignored.

Answer

If you exceed the limit then you'll receive a HTTP `429` error ('Rate Exceeded'). It's up to the client to retry those messages (as they haven't been received as they are above the rate limit).

What happens if the number of API calls for a SQS fifo queue exceeds the quota?

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