Configuring the gateway
You can install the optional gateway on one or more computers. Install the gateway if you plan on setting up advanced options, such as single sign-on with Kerberos security with IIS, or an architecture where the web server is publicly available outside a firewall.
IBM Cognos Analytics uses the web server for load balancing certain requests in addition to hosting and serving static content like icons and image files.
Ensure that the computer where you installed the active application services is configured and available before you configure the gateway computers.
The following diagram shows the gateway server and multiple Cognos Analytics servers. With load balancing enabled, the work load can be distributed across the servers.
This configuration is also recommended in a single application tier environment as the routing would just go to the one server and would be ready to add additional tier servers when needed.