Slow connections

Henry Paulissen h.paulissen at
Wed Dec 23 01:29:22 CET 2009

True and false.


When you dont define to close the connection it will do keep-alives.

The problem with this is that only the first header of the stream will be
checked against the acl's.


If you use haproxy only to load balance between http servers and not doing
routing based on url's (e.g. send \.(gif|jpg|png|jpeg) to static server and
all else to processing cluster), you may use keep-alives.




Van: Michael Fischer [mailto:michael at] 
Verzonden: woensdag 23 december 2009 1:12
Aan: Henry Paulissen
CC: Joe Williams; varnish-misc at
Onderwerp: Re: Slow connections


haproxy has never supported keep-alive HTTP connections, to my knowledge.




On Tue, Dec 22, 2009 at 3:41 PM, Henry Paulissen <h.paulissen at>

Next one.

Did you tune the tcp fin timeout? (on both servers)
Linux will standard holds all connection open till it hits the fin timeout
length (tcp_fin and tcp_fin2).
We decreased it to 3.

HAProxy support:
Do you forced a http connection close in haproxy?
If all connections are in keep-alive your queue will fill up real quick.


-----Oorspronkelijk bericht-----
Van: Joe Williams [mailto:joe at]
Verzonden: woensdag 23 december 2009 0:23
Aan: Henry Paulissen
CC: varnish-misc at
Onderwerp: Re: Slow connections

Thanks Henry, nf_conntrack_max is set high on both machines. I've had
the full table issue before :P

On 12/22/09 2:58 PM, Henry Paulissen wrote:
> Have a look to the conntrack setting in the kernel (sysctl) on both sides.
> It could be that your conntrack is full (connectrack only exists if you
> iptables with netfilter_conntrack).
> Regards,
> Henry
> -----Oorspronkelijk bericht-----
> Van: varnish-misc-bounces at
> [mailto:varnish-misc-bounces at] Namens Joe Williams
> Verzonden: dinsdag 22 december 2009 18:12
> Aan: varnish-misc at
> Onderwerp: Slow connections
> I am seeing a good amount (1/100) of connections to varnish (from
> haproxy) taking 3 seconds. My first thought was the connection backlog
> but somaxconn and listen_depth are both set higher than the number of
> connections. Anyone have any suggestions on how to track down what is
> causing this or settings I can use to try to aleviate it?
> Thanks.
> -Joe

Name: Joseph A. Williams
Email: joe at

varnish-misc mailing list
varnish-misc at


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

More information about the varnish-misc mailing list