I'm trying to debug an issue in my app and looking for suggestions or troubleshooting tips.
My app consists of a mobile app submitting data over HTTPS to apache (which is using mod_proxy to forward onto a django server). However, I've added logging at the django layer and it seems to indicate that the 400 is coming directly from Apache and not getting forwarded at all.
Also this only happens for a very small subset of POSTs. Due to the infrequency of the problem and the fact that it has been coming from phones that I don't have access to it has been difficult to reproduce and debug.
What types of things should I be looking at to troubleshoot this? I had found this post but I am already on Apache 2.2.22 so that doesn't appear to be the issue.
Because of the volume of requests I'm hesitant to add full logging to every request (though maybe I can do some conditional logging?).
Looking for suggestions on:
- What the root problem could be. E.g. what types of problems introduce intermittent 400s like this
- How to get more information on the server side to help diagnose, given that I can't get access to the client data.