opensafely-core / opensafely-core/proxy

premature client disconnects

Open
#20 2 comments 0 reactions 0 assignees View on GitHub

Nobody has claimed this yet.

Dominant language
Shell
Stars
0
Forks
1
Avg merge
2d 8h
Merged PRs (30d)
1

Description

We're seeing frequent client disconnects.

The dokku2 nginx logs show premature close, e.g.

2021/09/28 13:19:27 [error] 29908#29908: *1727134 upstream prematurely closed connection while reading upstream, client: 62.253.26.158

It looks like we are seeing this with larger uploads, but not always.

I noticed that uploads were being buffered, so I turned that off in proxy nginx config, but it doesn't seem to have worked.

It may be something todo with our double nginx thing. It might be worth redesigning the proxy as just nginx config that's dropped in to dokku's nginx, rather than running a separate nginx as a dokku app

It seems elevated starting this week (27/09/2021), and there were some network changes on the 26th, so have email TPP

Contributor guide

No contributing guide indexed for this repository

First steps

  1. Read the whole issue, then the project's contributing guide.
  2. Comment on the issue to say you are picking it up — it saves two people doing the same work.
  3. Fork the repository and make your change on a branch.
  4. Open a pull request that references the issue number.

Research direction

Start with the dokku2 nginx logs and the proxy nginx configuration, focusing on the premature upstream close during larger uploads. Compare the separate proxy nginx setup with the proposed nginx configuration dropped into dokku's nginx, and review the network changes from 26/09/2021. Done means identifying the cause and preventing the observed client disconnects.

Written by the indexing model from the issue text.

Assessment

Tech stack
nginx, shell
Domain
infrastructure, networking
Issue type
Bug
Difficulty
4/5
Estimated time
3-5 days
Activity status
Stale
Clarity
Needs clarification
Newbie friendliness
25/100

Get new issues in your inbox

A short digest of beginner-friendly GitHub issues.