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Posted to users@httpd.apache.org by Arunkumar Janarthanan <ar...@gmail.com> on 2010/01/27 15:36:22 UTC
[users@httpd] Apache Server status page shows uneven number of requests across load
balanced web servers
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
Re: [users@httpd] Apache Server status page shows uneven number of
requests across load balanced web servers
Posted by Arunkumar Janarthanan <ar...@gmail.com>.
Hi Peter,
The load balancer set for round robin minumweight based, that the request
transferred to the Apache instace has minimum connections.
Best Regards,
Arun J
On Thu, Jan 28, 2010 at 12:54 PM, <PM...@nypl.org> wrote:
> What is the persistence setting on the Load Balancers? Is it different if
> persistence is turned off competely? Weighting servers will throw this off
> completely.
>
>
> Thanks-
>
> Peter J. Milanese, Senior Systems Engineer
> Information Technology Group
> The New York Public Library
> peterm@nypl.org - 212.621.0203
>
>
>
>
>
> |------------>
> | From: |
> |------------>
>
> >--------------------------------------------------------------------------------------------------------------------------------------------------|
> |Arunkumar Janarthanan <ar...@gmail.com>
> |
> >--------------------------------------------------------------------------------------------------------------------------------------------------|
> |------------>
> | To: |
> |------------>
>
> >--------------------------------------------------------------------------------------------------------------------------------------------------|
> |users@httpd.apache.org
> |
> >--------------------------------------------------------------------------------------------------------------------------------------------------|
> |------------>
> | Date: |
> |------------>
>
> >--------------------------------------------------------------------------------------------------------------------------------------------------|
> |01/28/2010 12:41 PM
> |
>
> >--------------------------------------------------------------------------------------------------------------------------------------------------|
> |------------>
> | Subject: |
> |------------>
>
> >--------------------------------------------------------------------------------------------------------------------------------------------------|
> |Re: [users@httpd] Apache Server status page shows uneven number of
> requests across load balanced web servers |
> >--------------------------------------------------------------------------------------------------------------------------------------------------|
>
>
>
>
>
> Could anyone help me with this issue ? I still see the number of workes
> differing to each Apache though it configured for well load balancing ?
>
> On Wed, Jan 27, 2010 at 3:50 PM, Arunkumar Janarthanan <
> arunkumar.webadmin@gmail.com> wrote:
> Gary,
>
> Here is the netstat output attached from one of the webserver where the
> connections are on HIGH numbers. Regarding the load balancer I am trying
> to explore more setting options.
>
> Thanks again for looking into this issue.
>
> Best Regards,
> Arun J
>
>
> On Wed, Jan 27, 2010 at 2:49 PM, Gary Smith <ga...@holdstead.com>
> wrote:
> Arun,
>
>
>
>
>
> This is just a WAG, but I think that the problem still lies in the
> client side and how the load balancer is handling the requests. I would
> still be interested in seeing the netstat -atunep output from one of he
> affected machines when there is a high level of connections in a closed
> state. Even though the sessions aren’t sticky, is it possible that the
> load balancer is handling keep alive in such a way that it’s sending the
> back to the original server but on in a new state? (that’s a little
> beyond my knowledge though).
>
>
>
>
>
> Gary Smith
>
>
>
>
>
> From: Arunkumar Janarthanan [mailto:arunkumar.webadmin@gmail.com]
> Sent: Wednesday, January 27, 2010 11:37 AM
>
> To: users@httpd.apache.org
>
>
> Subject: Re: [users@httpd] Apache Server status page shows uneven number
> of requests across load balanced web servers
>
>
>
>
>
> Thanks Gary,
>
> The load balancing method we use is weight based, so apparently the load
> balancer suppose to send the traffic to the web server has least number
> of connections. However the Netscaler support confirmed they see
> eventual number of traffic routed to all 4 web servers.
>
> Regarding the Apache restart time, I restarted all 4 servers same time
> and checked could still see the requests on 1 & 3 are being handled. I
> dont think we have sticky session enabled at loadbalancer level.
>
> For the same problem we have not before changed the load balancer
> settings from sourceIP persistence to Weight based to have the load
> distributed equal on all the servers.
>
>
> IP port Type State Req/s
>
>
> 731-...30_80 x.x.x.x 80 HTTP UP 16/s
>
>
> 731-...31_80 x.x.x.x 80 HTTP UP 16/s
>
>
> 731-...31_80 x.x.x.x 80 HTTP UP 14/s
>
>
> 731-...55_80 x.x.x.x 80 HTTP UP 20/s
>
>
>
>
>
> Rsp/s Reqb/s Rspb/s ClntConn SvrConn MaxConn
> SurgeQ
>
>
> 731-...30_80 16/s 12406/s 345117/s 7 285 0
> 0
>
>
> 731-...31_80 16/s 10956/s 365025/s 7 262 0
> 0
>
>
> 731-...31_80 14/s 11140/s 368655/s 6 268 0
> 0
>
>
> 731-...55_80 20/s 14322/s 420105/s 7 272 0
> 0
>
>
>
>
>
>
>
>
> However the Apache server status still shows the number of requests
> being handled huge difference.
>
>
>
>
>
> I have attached the balancer-manager page as well with this email.
>
>
>
>
>
> Best Regards,
>
>
> Arun J
>
>
>
>
>
>
>
>
>
Re: [users@httpd] Apache Server status page shows uneven number of
requests across load balanced web servers
Posted by PM...@nypl.org.
What is the persistence setting on the Load Balancers? Is it different if
persistence is turned off competely? Weighting servers will throw this off
completely.
Thanks-
Peter J. Milanese, Senior Systems Engineer
Information Technology Group
The New York Public Library
peterm@nypl.org - 212.621.0203
|------------>
| From: |
|------------>
>--------------------------------------------------------------------------------------------------------------------------------------------------|
|Arunkumar Janarthanan <ar...@gmail.com> |
>--------------------------------------------------------------------------------------------------------------------------------------------------|
|------------>
| To: |
|------------>
>--------------------------------------------------------------------------------------------------------------------------------------------------|
|users@httpd.apache.org |
>--------------------------------------------------------------------------------------------------------------------------------------------------|
|------------>
| Date: |
|------------>
>--------------------------------------------------------------------------------------------------------------------------------------------------|
|01/28/2010 12:41 PM |
>--------------------------------------------------------------------------------------------------------------------------------------------------|
|------------>
| Subject: |
|------------>
>--------------------------------------------------------------------------------------------------------------------------------------------------|
|Re: [users@httpd] Apache Server status page shows uneven number of requests across load balanced web servers |
>--------------------------------------------------------------------------------------------------------------------------------------------------|
Could anyone help me with this issue ? I still see the number of workes
differing to each Apache though it configured for well load balancing ?
On Wed, Jan 27, 2010 at 3:50 PM, Arunkumar Janarthanan <
arunkumar.webadmin@gmail.com> wrote:
Gary,
Here is the netstat output attached from one of the webserver where the
connections are on HIGH numbers. Regarding the load balancer I am trying
to explore more setting options.
Thanks again for looking into this issue.
Best Regards,
Arun J
On Wed, Jan 27, 2010 at 2:49 PM, Gary Smith <ga...@holdstead.com>
wrote:
Arun,
This is just a WAG, but I think that the problem still lies in the
client side and how the load balancer is handling the requests. I would
still be interested in seeing the netstat -atunep output from one of he
affected machines when there is a high level of connections in a closed
state. Even though the sessions aren’t sticky, is it possible that the
load balancer is handling keep alive in such a way that it’s sending the
back to the original server but on in a new state? (that’s a little
beyond my knowledge though).
Gary Smith
From: Arunkumar Janarthanan [mailto:arunkumar.webadmin@gmail.com]
Sent: Wednesday, January 27, 2010 11:37 AM
To: users@httpd.apache.org
Subject: Re: [users@httpd] Apache Server status page shows uneven number
of requests across load balanced web servers
Thanks Gary,
The load balancing method we use is weight based, so apparently the load
balancer suppose to send the traffic to the web server has least number
of connections. However the Netscaler support confirmed they see
eventual number of traffic routed to all 4 web servers.
Regarding the Apache restart time, I restarted all 4 servers same time
and checked could still see the requests on 1 & 3 are being handled. I
dont think we have sticky session enabled at loadbalancer level.
For the same problem we have not before changed the load balancer
settings from sourceIP persistence to Weight based to have the load
distributed equal on all the servers.
IP port Type State Req/s
731-...30_80 x.x.x.x 80 HTTP UP 16/s
731-...31_80 x.x.x.x 80 HTTP UP 16/s
731-...31_80 x.x.x.x 80 HTTP UP 14/s
731-...55_80 x.x.x.x 80 HTTP UP 20/s
Rsp/s Reqb/s Rspb/s ClntConn SvrConn MaxConn
SurgeQ
731-...30_80 16/s 12406/s 345117/s 7 285 0
0
731-...31_80 16/s 10956/s 365025/s 7 262 0
0
731-...31_80 14/s 11140/s 368655/s 6 268 0
0
731-...55_80 20/s 14322/s 420105/s 7 272 0
0
However the Apache server status still shows the number of requests
being handled huge difference.
I have attached the balancer-manager page as well with this email.
Best Regards,
Arun J
Re: [users@httpd] Apache Server status page shows uneven number of
requests across load balanced web servers
Posted by Arunkumar Janarthanan <ar...@gmail.com>.
Could anyone help me with this issue ? I still see the number of workes
differing to each Apache though it configured for well load balancing ?
On Wed, Jan 27, 2010 at 3:50 PM, Arunkumar Janarthanan <
arunkumar.webadmin@gmail.com> wrote:
> Gary,
>
> Here is the netstat output attached from one of the webserver where the
> connections are on HIGH numbers. Regarding the load balancer I am trying to
> explore more setting options.
>
> Thanks again for looking into this issue.
>
> Best Regards,
> Arun J
>
>
> On Wed, Jan 27, 2010 at 2:49 PM, Gary Smith <ga...@holdstead.com>wrote:
>
>> Arun,
>>
>>
>>
>> This is just a WAG, but I think that the problem still lies in the client
>> side and how the load balancer is handling the requests. I would still be
>> interested in seeing the netstat -atunep output from one of he affected
>> machines when there is a high level of connections in a closed state. Even
>> though the sessions aren’t sticky, is it possible that the load balancer is
>> handling keep alive in such a way that it’s sending the back to the original
>> server but on in a new state? (that’s a little beyond my knowledge
>> though).
>>
>>
>>
>> Gary Smith
>>
>>
>>
>> *From:* Arunkumar Janarthanan [mailto:arunkumar.webadmin@gmail.com]
>> *Sent:* Wednesday, January 27, 2010 11:37 AM
>>
>> *To:* users@httpd.apache.org
>> *Subject:* Re: [users@httpd] Apache Server status page shows uneven
>> number of requests across load balanced web servers
>>
>>
>>
>> Thanks Gary,
>>
>> The load balancing method we use is weight based, so apparently the load
>> balancer suppose to send the traffic to the web server has least number of
>> connections. However the Netscaler support confirmed they see eventual
>> number of traffic routed to all 4 web servers.
>>
>> Regarding the Apache restart time, I restarted all 4 servers same time and
>> checked could still see the requests on 1 & 3 are being handled. I dont
>> think we have sticky session enabled at loadbalancer level.
>>
>> For the same problem we have not before changed the load balancer settings
>> from sourceIP persistence to Weight based to have the load distributed equal
>> on all the servers.
>>
>> IP port Type State Req/s
>>
>> 731-...30_80 x.x.x.x 80 HTTP UP 16/s
>>
>> 731-...31_80 x.x.x.x 80 HTTP UP 16/s
>>
>> 731-...31_80 x.x.x.x 80 HTTP UP 14/s
>>
>> 731-...55_80 x.x.x.x 80 HTTP UP 20/s
>>
>>
>>
>> Rsp/s Reqb/s Rspb/s ClntConn SvrConn MaxConn SurgeQ
>>
>> 731-...30_80 16/s 12406/s 345117/s 7 285 0 0
>>
>> 731-...31_80 16/s 10956/s 365025/s 7 262 0 0
>>
>> 731-...31_80 14/s 11140/s 368655/s 6 268 0 0
>>
>> 731-...55_80 20/s 14322/s 420105/s 7 272 0 0
>>
>>
>>
>>
>>
>> However the Apache server status still shows the number of requests being
>> handled huge difference.
>>
>>
>>
>> I have attached the balancer-manager page as well with this email.
>>
>>
>>
>> Best Regards,
>>
>> Arun J
>>
>>
>>
>>
>
Re: [users@httpd] Apache Server status page shows uneven number of
requests across load balanced web servers
Posted by Arunkumar Janarthanan <ar...@gmail.com>.
Gary,
Here is the netstat output attached from one of the webserver where the
connections are on HIGH numbers. Regarding the load balancer I am trying to
explore more setting options.
Thanks again for looking into this issue.
Best Regards,
Arun J
On Wed, Jan 27, 2010 at 2:49 PM, Gary Smith <ga...@holdstead.com>wrote:
> Arun,
>
>
>
> This is just a WAG, but I think that the problem still lies in the client
> side and how the load balancer is handling the requests. I would still be
> interested in seeing the netstat -atunep output from one of he affected
> machines when there is a high level of connections in a closed state. Even
> though the sessions aren�t sticky, is it possible that the load balancer is
> handling keep alive in such a way that it�s sending the back to the original
> server but on in a new state? (that�s a little beyond my knowledge
> though).
>
>
>
> Gary Smith
>
>
>
> *From:* Arunkumar Janarthanan [mailto:arunkumar.webadmin@gmail.com]
> *Sent:* Wednesday, January 27, 2010 11:37 AM
>
> *To:* users@httpd.apache.org
> *Subject:* Re: [users@httpd] Apache Server status page shows uneven number
> of requests across load balanced web servers
>
>
>
> Thanks Gary,
>
> The load balancing method we use is weight based, so apparently the load
> balancer suppose to send the traffic to the web server has least number of
> connections. However the Netscaler support confirmed they see eventual
> number of traffic routed to all 4 web servers.
>
> Regarding the Apache restart time, I restarted all 4 servers same time and
> checked could still see the requests on 1 & 3 are being handled. I dont
> think we have sticky session enabled at loadbalancer level.
>
> For the same problem we have not before changed the load balancer settings
> from sourceIP persistence to Weight based to have the load distributed equal
> on all the servers.
>
> IP port Type State Req/s
>
> 731-...30_80 x.x.x.x 80 HTTP UP 16/s
>
> 731-...31_80 x.x.x.x 80 HTTP UP 16/s
>
> 731-...31_80 x.x.x.x 80 HTTP UP 14/s
>
> 731-...55_80 x.x.x.x 80 HTTP UP 20/s
>
>
>
> Rsp/s Reqb/s Rspb/s ClntConn SvrConn MaxConn SurgeQ
>
> 731-...30_80 16/s 12406/s 345117/s 7 285 0 0
>
> 731-...31_80 16/s 10956/s 365025/s 7 262 0 0
>
> 731-...31_80 14/s 11140/s 368655/s 6 268 0 0
>
> 731-...55_80 20/s 14322/s 420105/s 7 272 0 0
>
>
>
>
>
> However the Apache server status still shows the number of requests being
> handled huge difference.
>
>
>
> I have attached the balancer-manager page as well with this email.
>
>
>
> Best Regards,
>
> Arun J
>
>
>
>
RE: [users@httpd] Apache Server status page shows uneven number of
requests across load balanced web servers
Posted by Gary Smith <ga...@holdstead.com>.
Arun,
This is just a WAG, but I think that the problem still lies in the client side and how the load balancer is handling the requests. I would still be interested in seeing the netstat -atunep output from one of he affected machines when there is a high level of connections in a closed state. Even though the sessions aren't sticky, is it possible that the load balancer is handling keep alive in such a way that it's sending the back to the original server but on in a new state? (that's a little beyond my knowledge though).
Gary Smith
From: Arunkumar Janarthanan [mailto:arunkumar.webadmin@gmail.com]
Sent: Wednesday, January 27, 2010 11:37 AM
To: users@httpd.apache.org
Subject: Re: [users@httpd] Apache Server status page shows uneven number of requests across load balanced web servers
Thanks Gary,
The load balancing method we use is weight based, so apparently the load balancer suppose to send the traffic to the web server has least number of connections. However the Netscaler support confirmed they see eventual number of traffic routed to all 4 web servers.
Regarding the Apache restart time, I restarted all 4 servers same time and checked could still see the requests on 1 & 3 are being handled. I dont think we have sticky session enabled at loadbalancer level.
For the same problem we have not before changed the load balancer settings from sourceIP persistence to Weight based to have the load distributed equal on all the servers.
IP port Type State Req/s
731-...30_80 x.x.x.x 80 HTTP UP 16/s
731-...31_80 x.x.x.x 80 HTTP UP 16/s
731-...31_80 x.x.x.x 80 HTTP UP 14/s
731-...55_80 x.x.x.x 80 HTTP UP 20/s
Rsp/s Reqb/s Rspb/s ClntConn SvrConn MaxConn SurgeQ
731-...30_80 16/s 12406/s 345117/s 7 285 0 0
731-...31_80 16/s 10956/s 365025/s 7 262 0 0
731-...31_80 14/s 11140/s 368655/s 6 268 0 0
731-...55_80 20/s 14322/s 420105/s 7 272 0 0
However the Apache server status still shows the number of requests being handled huge difference.
I have attached the balancer-manager page as well with this email.
Best Regards,
Arun J
Re: [users@httpd] Apache Server status page shows uneven number of
requests across load balanced web servers
Posted by Arunkumar Janarthanan <ar...@gmail.com>.
Thanks Gary,
The load balancing method we use is weight based, so apparently the load
balancer suppose to send the traffic to the web server has least number of
connections. However the Netscaler support confirmed they see eventual
number of traffic routed to all 4 web servers.
Regarding the Apache restart time, I restarted all 4 servers same time and
checked could still see the requests on 1 & 3 are being handled. I dont
think we have sticky session enabled at loadbalancer level.
For the same problem we have not before changed the load balancer settings
from sourceIP persistence to Weight based to have the load distributed equal
on all the servers.
IP port Type State Req/s
731-...30_80 x.x.x.x 80 HTTP UP 16/s
731-...31_80 x.x.x.x 80 HTTP UP 16/s
731-...31_80 x.x.x.x 80 HTTP UP 14/s
731-...55_80 x.x.x.x 80 HTTP UP 20/s
Rsp/s Reqb/s Rspb/s ClntConn SvrConn MaxConn SurgeQ
731-...30_80 16/s 12406/s 345117/s 7 285 0 0
731-...31_80 16/s 10956/s 365025/s 7 262 0 0
731-...31_80 14/s 11140/s 368655/s 6 268 0 0
731-...55_80 20/s 14322/s 420105/s 7 272 0 0
However the Apache server status still shows the number of requests being
handled huge difference.
I have attached the balancer-manager page as well with this email.
Best Regards,
Arun J
On Wed, Jan 27, 2010 at 12:25 PM, Gary Smith <ga...@holdstead.com>wrote:
> Arunkumar,
>
>
>
> There is no problem with what I see. The load balancer will balance a
> requester to a machine for a period of time. So if my web clients makes a
> request to your server, I will probably have a higher probability of getting
> that same server. Its like iptables connection tracking. Load balance
> doesnt necessarily mean equality service. There is also an unfair
> comparison going on here. The servers that are seeing all of the
> connections were restarted 1.5 days ago and the two that are working fine
> were started 6 days ago. If you are going to restart and then compare,
> restart all of them to compare. You mentioned that you are using weight
> load sharing algorithm. It is possible that when the two servers were
> restarted that the balancer is trying to give them a bigger weighted share
> to catch up to the other servers. I had a problem with this using ipvsadm
> some time ago when I would add a new server and give it the same schedule as
> the others it would be slammed for a while.
>
>
>
> When you see a lot of connections like that, do an netstat -atunep and see
> what the IP address and states are. Check to see if you have a bunch of
> duplicate IPs. If this is the case, its because the load balancer is
> gluing the connections during a session and that the IPs are also making
> multiple requests.
>
>
>
> Thats a place to start at least.
>
>
>
> Gary Smith
>
>
>
> *From:* Arunkumar Janarthanan [mailto:arunkumar.webadmin@gmail.com]
> *Sent:* Wednesday, January 27, 2010 6:36 AM
> *To:* users@httpd.apache.org
> *Subject:* [users@httpd] Apache Server status page shows uneven number of
> requests across load balanced web servers
>
>
>
> 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
>
RE: [users@httpd] Apache Server status page shows uneven number of
requests across load balanced web servers
Posted by Gary Smith <ga...@holdstead.com>.
Arunkumar,
There is no problem with what I see. The load balancer will balance a requester to a machine for a period of time. So if my web clients makes a request to your server, I will probably have a higher probability of getting that same server. It's like iptables connection tracking. Load balance doesn't necessarily mean equality service. There is also an unfair comparison going on here. The servers that are seeing all of the connections were restarted 1.5 days ago and the two that are working fine were started 6 days ago. If you are going to restart and then compare, restart all of them to compare. You mentioned that you are using weight load sharing algorithm. It is possible that when the two servers were restarted that the balancer is trying to give them a bigger weighted share to "catch up" to the other servers. I had a problem with this using ipvsadm some time ago when I would add a new server and give it the same schedule as the others it would be slammed for a while.
When you see a lot of connections like that, do an netstat -atunep and see what the IP address and states are. Check to see if you have a bunch of duplicate IP's. If this is the case, it's because the load balancer is gluing the connections during a session and that the IP's are also making multiple requests.
That's a place to start at least.
Gary Smith
From: Arunkumar Janarthanan [mailto:arunkumar.webadmin@gmail.com]
Sent: Wednesday, January 27, 2010 6:36 AM
To: users@httpd.apache.org
Subject: [users@httpd] Apache Server status page shows uneven number of requests across load balanced web servers
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
Re: [users@httpd] Apache Server status page shows uneven number of
requests across load balanced web servers
Posted by 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
Re: [users@httpd] Apache Server status page shows uneven number of
requests across load balanced web servers
Posted by 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
>
> ---------------------------------------------------------------------
> The official User-To-User support forum of the Apache HTTP Server Project.
> See <URL:http://httpd.apache.org/userslist.html> for more info.
> To unsubscribe, e-mail: users-unsubscribe@httpd.apache.org
> " from the digest: users-digest-unsubscribe@httpd.apache.org
> For additional commands, e-mail: users-help@httpd.apache.org
>
>
Re: [users@httpd] Apache Server status page shows uneven number of
requests across load balanced web servers
Posted by Nilesh Govindarajan <li...@itech7.com>.
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
>
>
>
>
> ---------------------------------------------------------------------
> The official User-To-User support forum of the Apache HTTP Server Project.
> See<URL:http://httpd.apache.org/userslist.html> for more info.
> To unsubscribe, e-mail: users-unsubscribe@httpd.apache.org
> " from the digest: users-digest-unsubscribe@httpd.apache.org
> For additional commands, e-mail: users-help@httpd.apache.org
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
---------------------------------------------------------------------
The official User-To-User support forum of the Apache HTTP Server Project.
See <URL:http://httpd.apache.org/userslist.html> for more info.
To unsubscribe, e-mail: users-unsubscribe@httpd.apache.org
" from the digest: users-digest-unsubscribe@httpd.apache.org
For additional commands, e-mail: users-help@httpd.apache.org