API calls to my server fail randomly [FastAPI]

Question

My usual response time is <50ms. Here's my tech:

Web Server: FastAPI+uvicorn
Proxy: nginx
DB: Postgres on VM
DB API: sqlalchemy+pg8000

There are two docker containers (~1GB) running on the VM.

However, the request wouldn't reach the server, and would timeout with 404 with the following exception (not reproducible):

sqlalchemy.exc.InterfaceError: (pg8000.exceptions.InterfaceError) network error

All servers are Azure D series VMs and in the same VNET.

I've had this issue previously, which I was able to solve by having only one docker on that VM. However, in this case both images are lightweight.

Impossible to answer without more details, [the error seems to imply a network issue though](https://pybrary.net/pg8000/errors.html) — Hedde van der Heide, Dec 29 '22 at 11:12
yes, I also feel it has less to do with code -- how do we solve network errors? I assumed having the same VNET with premium VM will do that. — ScriptKiddieOnAComputer, Dec 29 '22 at 12:06
Try using version 1.29.5 as this fixes a bug which would give the error you're seeing. — Tony Locke, May 29 '23 at 07:41
@TonyLocke thanks for replying. Can you please send any related links (I tried to look up) that explains this bug. Thank you. — ScriptKiddieOnAComputer, May 29 '23 at 14:08

score 1 · Accepted Answer · answered May 29 '23 at 19:01

There was a recent bug fix in pg8000 version 1.29.5 that may fix the problem you're seeing. Looking at the release notes the relevant bit is:

Fixed bug where pg8000 didn’t handle the case when the number of bytes received from a socket was fewer than requested. This was being interpreted as a network error, but in fact we just needed to wait until more bytes were available.

and the commit itself may be helpful.

API calls to my server fail randomly [FastAPI]

1 Answers1