[squid-users] Squid crashes with "!Comm::MonitorsRead(serverConnection->fd)"

[Marko Cupać]

Hi,

I am trying to set up ssl-bumped, kerberos-authenticated proxy with 4.3
on FreeBSD.

It works, but under load it crashes with the following message in
cache.log:

2018/11/07 12:41:45 kid1| assertion failed: http.cc:1530:
"!Comm::MonitorsRead(serverConnection->fd)"

I also get this message in squid jail's messages.log:

Nov  7 12:49:06 squid2 squid[86874]: Squid Parent: squid-1 process 3203
exited due to signal 6 with status 0

I suspected FreeBSD's low kern.ipc.somaxconn of 128, due to the
following in jail host's messages.log:
Nov  7 12:11:19 warden4 kernel: sonewconn: pcb 0xfffff8039fa301d0:
Listen queue overflow: 769 already in queue awaiting acceptance (334
occurrences)

However, after bumping it to 512 above message disappeared but squid
crashes remained.

I am monitoring queue length on jail host with `netstat -Lan', and I
notice, just before crash, queue goes way up, to more than 512, and
then goes back to 0 when squid restarts.

Maybe unrelated, but always around time of crash I see the following
line in squid's access.log:

1541590880.172      0 - TCP_MEM_HIT/200 1521 GET
http://www.microsoft.com/pki/certs/MicRooCerAut2011_2011_03_22.crt -
HIER_NONE/- application/octet-stream

Notice there's no client IP address in the line. How come? How can I
find out which clients request this?

Thank you in advance,

-- 
Before enlightenment - chop wood, draw water.
After  enlightenment - chip wood, draw water.

Marko Cupać
https://www.mimar.rs/