Subj : Re: CPU Hog
To   : Tracker1
From : deon
Date : Mon Aug 08 2022 09:54:45

  Re: Re: CPU Hog
  By: Tracker1 to deon on Sat Aug 06 2022 06:20 pm

 > What did your RAM usage look like? I've seen a similar issue a couple
 > times, where I couldn't connect on the mail service port... I don't know
 > what part of Synchronet was causing the issue... there was definitely
 > some kind of memory leak as I was getting a lot of out of memory errors.

Yeah, I am confident RAM wasnt the issue.

I've been running the same container config for 2+ years now, with the only different being an image update every now and again. (I can see from docker stats, that its happy with 168MB of 2G available to it.)

The problem started when I switched to a new ISP, that uses PPPoE. As a result all of my IPv6 traffic was affected by the lower MTU, and while I addressed that for my server LAN, I'm assuming it is affecting the docker lan (havent definitively confirmed that yet, but it seems likely).

Resetting the host (and the container) saw the CPU get back to 100% after a short while (with my fido hub trying to deliver me mail over IPv6). When he switched to IPv4, problem disappeared and CPU stays normal (< 5%).

My initial report of this was due to the fact that when I polled him with binkit, it didnt time out after 5 minutes (which IIRC is the "normal" timeout -  and I'm assuming since he is using binkd his side would have) and I was thinking that subsequent binkit -p polls were "adding" to the issue (together with him polling me as well).

(And I dont think my side would have closed down when his side sent the TCP_FIN as a result of the binkd timeout, since there was (probably) other defragged packets that werent successfully delivered yet.)

What's also strange, I've learnt that his side is also PPPoE, and I was only having this issue with his system - my other IPv6 connections were not affected.

Not sure why a hung poll would also peg 2 cores as technically my side is waiting to receive - perhaps the repeated system call to check if there is data on the wire does result in this?


....лоеп

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