[+] Re: Breaking Varnish

[Niall O'Higgins]

On Wed, Jan 28, 2009 at 09:54:26AM +0000, Poul-Henning Kamp wrote:
> >I've re-run the load test against varnish-trunk.  Trunk is better
> >behaved, but I now get output like this over and over:
> >
> >child (19731) Started
> >Child (19731) said Closed fds: 4 7 8 10 11
> >Child (19731) said Child starts
> >Child (19731) said managed to mmap 49929912320 bytes of 49929912320
> >Child (19731) said Ready
> >Child (19731) not responding to ping, killing it.
> 
> This is a typical indication of raw overload, what levels of traffic
> are you hitting it with ?

This kind of thing:

Transaction rate:            3776.65 trans/sec
Throughput:                     1.68 MB/sec
Concurrency:                   28.28

Does the parent process give up on restarting the child after a
certain number of failures?  I was surprised by the eventual complete
exit of varnishd with the message:

Pushing vcls failed: CLI communication error

Also, Varnish seems to be able to handle up to about double that load
for a while (we got up to 6701 t/sec), then it dies as above.  Seems
like it takes around 2-3 hours for the varnishd parent process
to die.

> 
> -- 
> Poul-Henning Kamp       | UNIX since Zilog Zeus 3.20
> phk at FreeBSD.ORG         | TCP/IP since RFC 956
> FreeBSD committer       | BSD since 4.3-tahoe    
> Never attribute to malice what can adequately be explained by incompetence.
> 

-- 
Niall O'Higgins
Software Engineer
Metaweb Technologies, Inc.