How to debug a 503 service unavailable error

I was doing some work, making some calls against my service, with no change to code or deployment. The service was running for past 24 hours with lots of calls against it and no problems. I somehow found myself in a situation where any GET request to an entity now fails with a 503:

HTTP/2 503

upstream connect error or disconnect/reset before headers. reset reason: remote refused stream reset

There is no information in any logs to help me here. How should one proceed with debugging?

Could you send me a DM with the service name, your project UUID, your user UUID, and an estimate on when it occurred? If there’s nothing in the logs, I’ll ask our Ops team to check it out. You can get the project and user UUID by running

akkasls project list

The project UUID will be listed under the column ID and your user UUID will be listed under the column Owner.