Distributed installation.

[monica]

Hi All,

I have some doubts on distibuted installation.
I am going to install 2 instances (GW+CM+APP) on 2 servers. I am planning to configure as below,

on server 1
------------
1)Dispatcher url1
2)Dispatcher url2

1) CM url1
2) CM url2

on server 2
---------------

1)Dispatcher url2
2)Dispatcher url1

1) CM url2
2) CM url1

Is this order of configuring URL's are correct ?. I am really confused about the CM url since some IBM docs says on the standby CM computer order must be CM2,CM1...but some doc says CM1,CM2

http://publib.boulder.ibm.com/infocenter/c8bi/v8r4m0/index.jsp?topic=/com.ibm.swg.im.cognos.inst_cr_winux.8.4.0.doc/inst_cr_winux_id8157ConfigureCMenvironmentproperties.html

http://www-01.ibm.com/support/docview.wss?uid=swg21340821


Secondly we are using external load balancer so round robin method in the dispatcher setting really makes any sense ? Do I need to change it to cluster mode..

--Monica

[MFGF]

Hi,

Dealing with these in reverse order...

If you are using an external load balancer, turn off the dispatcher load balancing between servers by setting each dispatcher to Cluster Compatible. Each dispatcher will still load balance requests between the available report services on the local server, but will not hand off requests to the other server - which is what you want here.

Are you going with two gateways (ie two web server instances) and load balancing between these?  If so, you should probably configure each gateway to point to the dispatcher on the machine it's installed on as the first choice, and the dispatcher on the other server as the second choice (so that they will fail over to each other if the Cognos 10 service stops or dies on the local server).

You can only have ONE ACTIVE Content Manager. You will need to pick one of the servers to be the main (active) CM and the other as the standby. Both servers should be configured with these in the same order (eg both CM1 then CM2 or both CM2 then CM1).

Cheers!

MF.

[monica]

Thank you very much MFGF for your reply... I am having another small question . If I use external load balancers and keep load balancing mode as the "round robin" itself without the changing it to "cluster compatible" ...does this cause any issue ?

--Monica

[Grim]

No it shouldn't cause any issues, but Cognos will be handing off requests as it sees fit (well at least based on how it's configured). So if you expecting that your LB to send a request to a specific machine that request may get handed to another dispatcher by Cognos.

Here's some reading homework for you...

IBM Cognos BI Dispatcher Routing Explained
http://www.ibm.com/developerworks/data/library/cognos/infrastructure/cognos_specific/page510.html

Web/GW Scalability and load balancing
http://pic.dhe.ibm.com/infocenter/cbi/v10r1m1/index.jsp?topic=%2Fcom.ibm.swg.ba.cognos.crn_arch.10.1.1.doc%2Fc_arch_loadbalancing.html

Cluster compatible
http://pic.dhe.ibm.com/infocenter/caapps/v10r1m0/index.jsp?topic=%2Fcom.ibm.swg.im.cognos.ug_cra.10.1.0.doc%2Fug_cra_id8629cluster_compatible_mode.html

[MFGF]

Thank you very much MFGF for your reply... I am having another small question . If I use external load balancers and keep load balancing mode as the "round robin" itself without the changing it to "cluster compatible" ...does this cause any issue ?

--Monica

It just means that the dispatchers are doing more work than they need to in performing inter-server load balancing of their own. They will still be checking the utilisation of the local report server processes, and will start handing off requests to the other server if they deem it appropriate (ie if half the report services are being utilised on the current machine). As Grim says, it shouldn't cause any issues, but if you are handling the load balancing externally, why would you want your Cognos servers to do the same work again?

MF.