Getting "Connection to ...azure.com timed out. (connect timeout=300)" when doing many calls to begin_analyze_document

Question

We are trying out azure document intelligence from python. In particular we are using client.begin_analyze_document() with model id prebuilt-read. When we are doing a load test, a large amount of requests continuously for several minutes, we are getting a timeout error. From the docs we were expecting a 429 error, instead of a timeout, see here. This is problematic because instead of a failure which could be used to control the requests rate and do retries, the calls just take a long time delaying the entire process.

Do we have wrong expectations of getting a 429 error? Or are we misconfiguring something which is why we get the timeout behavior?

We have tried both azure-ai-formrecognizer and the new azure-ai-documentintelligence which both produce the timeouts. And the stack trace we get is attached.

stacktrace-formrecognizer.txt

stacktrace-documentintelligence.txt

Thanks!