Slow connections

[Joe Williams]

Any other suggestions? Another analysis of the logs shows that varnish 
vs other backends (CouchDB) I see an order of magnitude higher 
percentage of 3 second connection times with varnish.

Here's my varnish command options 
http://friendpaste.com/1Zvj1XkX75eKqdzrJQZcfK  and my sysctl changes 
http://friendpaste.com/3lt3uhIm1NTNhrqGxvQEX6 the sysctl on haproxy is 
identical.

If it makes a difference my VCL is pretty simple just with some header 
rewrites, round robin for 8 backend servers, exclusions for certain 
URI's and etc.

Thanks again!

-Joe


On 12/22/09 4:45 PM, Joe Williams wrote:
> Michael,
>
> I've looked at it for a bit and see 0's across the board for the 
> connections between the two machines.
>
> To that end it looks like I rarely have above 500 connections into 
> varnish.
>
> -Joe
>
>
> On 12/22/09 3:24 PM, Michael Fischer wrote:
>> Are you seeing any increased TCP send queue lengths on the haproxy 
>> side, or TCP receive queue lengths on the Varnish side?  (netstat -a) 
>>  That might provide some clue as to what's going on.
>>
>> --Michael
>>
>> On Tue, Dec 22, 2009 at 2:58 PM, Henry Paulissen 
>> <h.paulissen at qbell.nl <mailto:h.paulissen at qbell.nl>> 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 use
>>     iptables with netfilter_conntrack).
>>
>>     Regards,
>>     Henry
>>
>>     -----Oorspronkelijk bericht-----
>>     Van: varnish-misc-bounces at projects.linpro.no
>>     <mailto:varnish-misc-bounces at projects.linpro.no>
>>     [mailto:varnish-misc-bounces at projects.linpro.no
>>     <mailto:varnish-misc-bounces at projects.linpro.no>] Namens Joe Williams
>>     Verzonden: dinsdag 22 december 2009 18:12
>>     Aan: varnish-misc at projects.linpro.no
>>     <mailto:varnish-misc at projects.linpro.no>
>>     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 joetify.com <mailto:joe at joetify.com>
>>     Blog: http://www.joeandmotorboat.com/
>>
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>
> -- 
> Name: Joseph A. Williams
> Email:joe at joetify.com
> Blog:http://www.joeandmotorboat.com/
>    
>
>
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>    

-- 
Name: Joseph A. Williams
Email: joe at joetify.com
Blog: http://www.joeandmotorboat.com/

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