Varnish child killed

Jean-Francois Laurens jean-francois.laurens at
Wed Apr 27 09:59:33 CEST 2011

HI Thiago !

Thank you a lot for your very interesting comment !

In fact I get the same limitation with a 8GB memory server.

Please correct me if I¹m wrong :
My system has only 8GB of memory. Thus I can assume that the kernel should
have stared to write dirty mmap'ed pages longer in advance than your server

But the very high loads I¹ve seen are only occuring once the cache became
close to 20GB+.
Why is that ? I still don¹t understand this 20GB+ limitation.

I addition of the vmstat and ps that I collect regularly, I will add an
iostat to watch the disk activity.


Le 27/04/11 00:26, « Thiago Figueiro » a écrit :

> From: Jean-Francois Laurens
>> > Hi there,
>> > Apr 20 21:48:43 server-01-39 varnishd[21087]: Child (5372) not responding
>> > to CLI, killing it.
> Hi!  I'm a bit late to the discussion (happy Easter everyone!) but we came
> across this issue on Linux earlier this year.
> You didn't send charts for your disk IO but I'm betting it looks busy.  If
> this is so, it may be the kernel pre-empting writing of dirty mmap pages to
> disk.
> I investigated the issue at the time and found that on the RHEL 5 vanilla
> kernel the Varnish child was being blocked by kernel IO. This caused the
> parent pings to time-out:
> TL;DR: 
> echo 0 > /proc/sys/vm/flush_mmap_pages
> Good luck,
> Thiago.
> ______________________________________________________
> This electronic mail message, including any and/or all attachments, is for the
> sole use of the intended recipient(s), and may contain confidential and/or
> privileged information, pertaining to business conducted under the direction
> and supervision of the sending organization. All electronic mail messages,
> which may have been established as expressed views and/or opinions (stated
> either within the electronic mail message or any of its attachments), are left
> to the sole responsibility of that of the sender, and are not necessarily
> attributed to the sending organization. Unauthorized interception, review,
> use, disclosure or distribution of any such information contained within this
> electronic mail message and/or its attachment(s), is (are) strictly
> prohibited. If you are not the intended recipient, please contact the sender
> by replying to this electronic mail message, along with the destruction all
> copies of the original electronic mail message (along with any attachments).
> ______________________________________________________
> Jean-Francois Laurens
> Ingénieur Système Unix
> Resources et Développement
> Secteur Backend
> RTS - Radio Télévision Suisse
> Quai Ernest-Ansermet 20
> Case postale 234 
> CH - 1211 Genève 8
> T +41 (0)58 236 81 63

-------------- next part --------------
An HTML attachment was scrubbed...
URL: <>

More information about the varnish-misc mailing list