Octopi + Mac + ESET = http connection issues

What is the problem?
Eset's Cyber Security Web access protection on Mac is causing problems with accessing Octoprint behind Haproxy (default Octopi configuration).

After a few hours of running fine, HTTP connections to Octopi starts to hang up indefinitely. All requests just stays open for minutes. It happens in all browsers at the same time. Disabling the Web access protection in Eset restores connectivity. A restart of my Mac does help too, but again, only temporarily.

Initially, I investigated this as an issue with Octopi, until I found out that I can still connect from a different PC. So I wrote this post across more days as I investigated it. I will try to raise this with Eset as well, but in case someone else had the same issue or had an idea what could be the reason or how to prevent it, I'm writing it here too.

What did you already try to solve it?

  • Raspberry restart
  • Manual restart of haproxy service
  • Overwriting the sd card with a fresh image - the issue manifested again.
  • Restart of my Mac
  • Disabling Eset web protection

(syslog, dmesg, ... no logs, no support)

I have no idea what should I provide here. I didn't find any error in any log. Haproxy is not even logging access and I didn't see the starving connections to make it to Octoprint. And Eset doesn't show it in a list of blocked connections either.

$ haproxy --version
HA-Proxy version 1.8.19-1+rpi1 2019/03/14
Copyright 2000-2019 Willy Tarreau <willy@haproxy.org>

The version of octoprint: happened with both 1.4.0 and 1.3.12

Eset Cyber Security version: 6.8.300.0

Additional information about your network

  • I'm using Raspberry 4B with 4 GB RAM and a fresh octopi image downloaded today (May 19th).
  • I did NOT update any package in the system. However, I did a check and haproxy is up-to-date.
  • I can ssh into the rpi, it is really only about http (and maybe on standard ports - I could connect on port 5000 if I avoided haproxy)
  • I'm connected through wifi. Signal is stable, not dropping.
  • I changed the hostname to a custom name that's resolvable by my local DNS.
  • Almost no CPU load and only 160 MB of RAM is used.
  • Router is a Mikrotik with current updates.
  • I'm connecting within a local network (192.168.x.0/24), no proxy between me and the Raspberry Pi.