Does Canvas REST API automatically restricting IP?

lang1

Our application has a very robust integration with Canvas for the last 15yrs. However, we started seeing certain servers are no longer access the Canvas API. It keeps getting null response on OAUTH authentication. Same integration moved to another server with the same Canvas LMS account and it works fine.

siekmang

I'm wondering if the servers that are having issues have triggered the dynamic throttling and somewhere along the path, whether it's security measures or error handling in the code, instead of delivering the 429 error, you're getting a null response. Alternatively, could it be a stale environment issue(e.x. outdated DNS cache or an old hosts file?)