Ignoring health checks in statistics

[Caunter, Stefan]

The example satisfies a check for a text string that would keep varnish
"in the pool". 
"Health" is different, and configurable based on agreed parameters
defined in the load balancer based on expected backend behaviour. 

If varnish cannot send a 404 it would be a problem I think.

Stefan Caunter :: Senior Systems Administrator :: TOPS
e: scaunter at topscms.com  ::  m: (416) 561-4871
www.thestar.com www.topscms.com

-----Original Message-----
From: varnish-dev-bounces at varnish-cache.org
[mailto:varnish-dev-bounces at varnish-cache.org] On Behalf Of Frank
Gruellich
Sent: April-01-10 8:20 AM
To: varnish-dev at varnish-cache.org
Subject: Re: Ignoring health checks in statistics

Hi,

okay, I'll have to see if I can make our load balancer to consider an
HTTP 404 as healthy...  Or could I simple say error 200 "I am OK"?

Can I make this dependent on the health of my backend?  Would something
like this

sub vcl_recv
{
	set req.backend = my_backend;
	if (req.url = "/static.txt")
	{
		if (req.backend.healthy)
		{
			error 200 "I am OK";
		}
		else
		{
			error 404 "I am not OK";
		}
	}
}

work and still not have that counted in statistics?

Kind regards,
 Frank.

On 03/23/10 14:11, Caunter, Stefan wrote:
> Just put this in sub vcl_recv
> 
> else {
>                  error 404 "I am OK";
>      }
> 
> 
> Stefan Caunter :: Senior Systems Administrator :: TOPS
> e: scaunter at topscms.com  ::  m: (416) 561-4871 www.thestar.com 
> www.topscms.com
> 
> -----Original Message-----
> From: varnish-dev-bounces at varnish-cache.org
> [mailto:varnish-dev-bounces at varnish-cache.org] On Behalf Of Frank 
> Gruellich
> Sent: March-23-10 7:03 AM
> To: varnish-dev at varnish-cache.org
> Subject: Ignoring health checks in statistics
> 
> Hi,
> 
> we have two Varnish instances and a load balancer in front.  The load 
> balancer periodically polls the varnishd's for a static file (lying 
> also at all the backend servers) to check if varnishd is still 
> working.  It does that once per second.  This completely messes up 
> statistics like hit ratio because that static file is served from 
> cache all the time, so currently our hit ratio is close to 99.9%.  I 
> would like to have counted this specific file neither as miss nor hit,

> but just serve it and ignore it otherwise.  It doesn't even need to be
logged.
> 
> haproxy has an option monitor-net where you can specify that it does 
> not need to log requests from that subnet.  Does varnish offer a 
> similar option?  Or is there some cool VCL snippet I could add?
> 
> Thanks in advance.
> 
> Kind regards,
> --
> Navteq (DE) GmbH
> Frank Gruellich
> Map24 Systems and Networks
> 
> Duesseldorfer Strasse 40a
> 65760 Eschborn
> Germany
> 
> Phone:      +49 6196 77756-414
> Fax:        +49 6196 77756-100
> 
> HRB 46215, Local Court Frankfurt am Main Managing Directors: Thomas 
> Golob, Hans Pieter Gieszen, Martin Robert Stockman
> USt-ID-No.: DE 197947163
> 
> 
> 
> 

Mit freundlichen Gruessen,
Kind regards,
--
Navteq (DE) GmbH
Frank Gruellich
Map24 Systems and Networks

Duesseldorfer Strasse 40a
65760 Eschborn
Germany

Phone:      +49 6196 77756-414
Fax:        +49 6196 77756-100

HRB 46215, Local Court Frankfurt am Main Managing Directors: Thomas
Golob, Hans Pieter Gieszen, Martin Robert Stockman
USt-ID-No.: DE 197947163