Child process recurrently being restarted

[Stefano Baldo]

Hello.

I am having a critical problem with Varnish Cache in production for over a
month and any help will be appreciated.
The problem is that Varnish child process is recurrently being restarted
after 10~20h of use, with the following message:

Jun 23 09:15:13 b858e4a8bd72 varnishd[11816]: Child (11824) not responding
to CLI, killed it.
Jun 23 09:15:13 b858e4a8bd72 varnishd[11816]: Unexpected reply from ping:
400 CLI communication error
Jun 23 09:15:13 b858e4a8bd72 varnishd[11816]: Child (11824) died signal=9
Jun 23 09:15:14 b858e4a8bd72 varnishd[11816]: Child cleanup complete
Jun 23 09:15:14 b858e4a8bd72 varnishd[11816]: Child (24038) Started
Jun 23 09:15:14 b858e4a8bd72 varnishd[11816]: Child (24038) said Child
starts
Jun 23 09:15:14 b858e4a8bd72 varnishd[11816]: Child (24038) said SMF.s0
mmap'ed 483183820800 bytes of 483183820800

The following link is the varnishstat output just 1 minute before a restart:

https://pastebin.com/g0g5RVTs

Environment:

varnish-5.1.2 revision 6ece695
Debian 8.7 - Debian GNU/Linux 8 (3.16.0)
Installed using pre-built package from official repo at packagecloud.io
CPU 2x2.9 GHz
Mem 3.69 GiB
Running inside a Docker container
NFILES=131072
MEMLOCK=82000

Additional info:

- I need to cache a large number of objets and the cache should last for
almost a week, so I have set up a 450G storage space, I don't know if this
is a problem;
- I use ban a lot. There was about 40k bans in the system just before the
last crash. I really don't know if this is too much or may have anything to
do with it;
- No registered CPU spikes (almost always by 30%);
- No panic is reported, the only info I can retrieve is from syslog;
- During all the time, event moments before the crashes, everything is okay
and requests are being responded very fast.

Best,
Stefano Baldo
-------------- next part --------------
An HTML attachment was scrubbed...
URL: <https://www.varnish-cache.org/lists/pipermail/varnish-misc/attachments/20170623/cefe7ad3/attachment.html>