How to Install/Configure second Cognos server for load balancing?

[kalyanrc]

Hi,
We have a production server A with version 10.2.1 that has all components on it - Web server with IIS and hosts the prod Cognos website, Gateway, Dispatcher and Content Manager. We run about 20K reports over month end and they are taking too long about 50 Hrs. The report requests are sent through another app which sends them directly to the dispatcher on server A. 

We are trying to set up a second production server B to load balance the 20K report run.
1. Do I install the gateway also on the second server or just Application Tier Components (Dispatcher) and content manager?
2. How do I set up the configuration for second server  B on Config window? Is the following correct?

Gateway Settings
Gateway URI : ServerB or Server A?
Dispatcher URI for gateway: ServerB URI
Controller URI for gateway: ServerB URI
Dispatcher Settings
External Dispatcher URI: ServerB URI
Internal Dispatcher URI: ServerB URI
Other URI Settings
Dispatcher URI for External applications: ServerB URI
Content Manager URI: ServerB URI (But points to same content store database for both servers)

3. Config changes for server A is to only add the new dispatcher, are there any other changes to be made?
Dispatcher URI for gateway: Server A and ServerB URIs

[MFGF]

Hi,
We have a production server A with version 10.2.1 that has all components on it - Web server with IIS and hosts the prod Cognos website, Gateway, Dispatcher and Content Manager. We run about 20K reports over month end and they are taking too long about 50 Hrs. The report requests are sent through another app which sends them directly to the dispatcher on server A. 

We are trying to set up a second production server B to load balance the 20K report run.
1. Do I install the gateway also on the second server or just Application Tier Components (Dispatcher) and content manager?
2. How do I set up the configuration for second server  B on Config window? Is the following correct?

Gateway Settings
Gateway URI : ServerB or Server A?
Dispatcher URI for gateway: ServerB URI
Controller URI for gateway: ServerB URI
Dispatcher Settings
External Dispatcher URI: ServerB URI
Internal Dispatcher URI: ServerB URI
Other URI Settings
Dispatcher URI for External applications: ServerB URI
Content Manager URI: ServerB URI (But points to same content store database for both servers)

3. Config changes for server A is to only add the new dispatcher, are there any other changes to be made?
Dispatcher URI for gateway: Server A and ServerB URIs

Hi.

1. You don't need another gateway. You don't even need another content manager - just the Application Tier components need to be installed.
2. The second server needs to point to the gateway and the content manager URIs on the first server. That's it.
3. You don't need to change the config on the first server. When you configure and start the second server it will auto-register itself in the instance.

The dispatcher on the first server will act as the load balancer - when the first server has more than 50% of its report service connections in use, the dispatcher will route requests to the dispatcher on the second server. It assumes by default that both servers have the same processing capacity, and load-balances evenly between them. If this is not the case, you need to change the weighting on one server or the other to reflect how the requests should be proportionally split between the servers. You do this in the Administration Console - you will see both dispatchers and you can change the weighting of either.

You only need a second gateway and a second content manager if you also want failover. From the looks of your post, this isn't your requirement though?

Cheers!

MF.

[kalyanrc]

MF,
Thanks for your feedback, my config settings for load balancing are clear now. It is actually for load balancing and fail over also. So, I will be installing all three - Gateway, Dispatcher and Content Manager on Server B.
1. Then what are my Config options on Server A and B?
2. Let's say that Dispatcher A is not available as server A is down, How does Report processing occur?

[smiley]

The build in load balancing and fail over is on Dispatcher and Content Manager level only, and fully automated.
When server A is down, end users will have to go to http://serverb/ibmcognos manually, as the webtier does not have build in redundancy.
If you want that also, you will need a hardware load balancer in front. 

[MFGF]

MF,
Thanks for your feedback, my config settings for load balancing are clear now. It is actually for load balancing and fail over also. So, I will be installing all three - Gateway, Dispatcher and Content Manager on Server B.
1. Then what are my Config options on Server A and B?
2. Let's say that Dispatcher A is not available as server A is down, How does Report processing occur?

In that case the gateway on each machine will need to be configured to point to both dispatchers. I'd put Dispatcher A first in the list and Dispatcher B second in the list on both servers. The content manager on server B will point to the same content store database as the one on server A, and will point to the same authentication provider too. Make sure you start the Cognos service on server A before server B so that the content manager on server A is live and the one on B is standby. You will need both content manager URIs entering into the config on both machines - put the server A URI first in the list on both of them.

As there will be two web servers - one for each gateway - each will have a different host name or IP address. If server A fails, server B will continue to run and the content manager will become live, but your users will need to use the URL for server B's gateway. The only way to prevent this is (as smiley indicates) to put a hardware load balancer in front of the two gateways and to have the URL for this as the single URL for all users. However, what happens if that load balancer fails? :)

Cheers!

MF.

[nsaxena]

Make sure you start the Cognos service on server A before server B so that the content manager on server A is live and the one on B is standby. You will need both content manager URIs entering into the config on both machines - put the server A URI first in the list on both of them.


Cheers!

MF.

Hi MF, i love reading your post. Its so descriptive . One doubt regarding restarting of services. Suppose we install gateway,CM and dispatcher in different locations...so we will have 3 configuration portals and hence 3 IBM Cognos service to restart. One for Gateway,CM and dispatcher.
In such case what should be order of restart..and logic if any. Thanks!

[MFGF]

Hi MF, i love reading your post. Its so descriptive .

Thank you, kind sir!! :)

One doubt regarding restarting of services. Suppose we install gateway,CM and dispatcher in different locations...so we will have 3 configuration portals and hence 3 IBM Cognos service to restart. One for Gateway,CM and dispatcher.
In such case what should be order of restart..and logic if any. Thanks!

Yep. Entirely feasible. The order in which to start them is

1. Content Manager
2. Application server
3. Er, there isn't a 3. The gateway isn't a service so there's nothing Cognos-specific to start. I suppose you could argue you need to start the web server service, so let's go with that :)

You always need to have the primary content manager started first. It defines/controls the crypto keys for the entire instance. Follow that with your application server(s) and any standby content manager(s) in whatever order you like. If you're doing an initial configuration and start following a multi-server install, you need to:

1. Configure, Save and Start the Content Manager
2. Configure, Save and Start the Application Server
3. Configure and save the Gateway.

Cheers!

MF.