I’ve been prototyping an app with Fly.io using node. I have an endpoint where users can POST a file to be uploaded into a s3 bucket.
When trying this out locally, upload latencies were reasonable in the sub ~100ms range. However, the same service when deployed to Fly results in uploads of over 3 seconds for files that are larger than ~30KB. For smaller files the latencies are within the same ballpark as local dev, which makes this even more puzzling.
I’ve tried scaling up to 2x dedicated CPU but that resulted in no changes to the upload latencies. The S3 bucket is located in us-west-1 and my Fly app is in sjc, so that should rule out physical distance as a cause as well.
Any ideas what could be the issue? Happy to provide more details over DM to help with the investigation (my prototype doesn’t have auth at the moment haha…).