Re: [users@httpd] Apache Server status page shows uneven number of requests across load balanced web servers

[Arunkumar Janarthanan <ar...@gmail.com>]

Hi Nilesh,

Thanks for your response.

I have already checked this with Load balancer support found the requests
are getting sitributed eventually from Netscaler end.

So was chekcing if this could be an issue or known behaviour with Apache.

Best Regards,
Arun J

On Wed, Jan 27, 2010 at 9:43 AM, Nilesh Govindarajan <li...@itech7.com>wrote:

> On 01/27/2010 08:06 PM, Arunkumar Janarthanan wrote:
>
>> Hello All,
>>
>> We have apache servers running on RedHat Linux physical servers, all 4
>> servers are balanced by Citrix Netscaler 8.1 load balancer with round
>> robin weight load sharing algorithm.
>>
>> However when I check the server status page to find the number of
>> requests are served by each Apache server is showing uneven load /
>> number of requests being processed by each Apache.
>>
>> I notice the load always getting processed by two specific Apache
>> instances, here are the configuration details.
>>
>> Attached here the server status screen shot page of all 4 web servers.
>>
>> [root@web bin]# ./apachectl -version
>>
>> Server version: Apache/2.2.6 (Unix)
>>
>> Server built: Sep 26 2007 11:18:50
>>
>> [root@web bin]#
>>
>> Operating System:
>>
>> Linux Host1 2.4.21-53.ELsmp #1 SMP Wed Nov 14 03:54:12 EST 2007 i686
>> i686 i386 GNU/Linux
>>
>> Hardware configuration are same for all 4 physical Linux servers.
>>
>> Please advice.
>>
>> Best Regards,
>>
>> Arun J
>>
>>
>>
>>
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>
> You're at the wrong place my friend. This is not a Citrix Netscaler Support
> list. Check with them. Its rare you'll get any help here.
>
> --
> Nilesh Govindarajan
> Site & Server Adminstrator
> www.itech7.com
>
> ---------------------------------------------------------------------
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> See <URL:http://httpd.apache.org/userslist.html> for more info.
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>

Re: [users@httpd] Apache Server status page shows uneven number of requests across load balanced web servers

[Mark Watts <m....@eris.qinetiq.com>]

On Wed, 2010-01-27 at 09:47 -0500, Arunkumar Janarthanan wrote:
> Hi Nilesh,
> 
> Thanks for your response.
> 
> I have already checked this with Load balancer support found the
> requests are getting sitributed eventually from Netscaler end.
> 
> So was chekcing if this could be an issue or known behaviour with
> Apache.

If the load-balancer is doing true Round Robin, then 1/N requests will
be sent to each server.
If you are not seeing that, then the load-balancer isn't sending the
requests in the first place.

For example, I have an Apache 2.x proxy/balancer here
and /balancer-status is telling me that exactly 1/2 of my requests are
going to each of my 2 back-end servers.


If you could paste some actual numbers, that would help.

Mark.

-- 
Mark Watts BSc RHCE MBCS
Senior Systems Engineer, Managed Services Manpower
www.QinetiQ.com
QinetiQ - Delivering customer-focused solutions
GPG Key: http://www.linux-corner.info/mwatts.gpg