An environment has two dispatchers with report servers installed on two machines with following configuration:Dispatcher...

If your installation includes more than one dispatcher, you can specify the proportion of requests that each dispatcher handles by changing their processing capacity.

This is commonly referred to as load balancing. You typically set the capacity for a dispatcher based on the CPU speed of the computer where it is installed.

For example, a first dispatcher is installed on a 2 GHz computer and a second dispatcher on a 1 GHz computer. You set the processing capacity of the first dispatcher to 2.0 and the second to 1.0. The first dispatcher handles two-thirds of the requests while the second handles one-third of the requests. If you set the capacity of both dispatchers to 1.0, requests are sent to each dispatcher alternately.

The default processing capacity for each dispatcher is 1.0.

References: https://www.ibm.com/support/knowledgecenter/SSEP7J_11.0.0/com.ibm.swg.ba.cognos.ug_cra.doc/t_balancerequestsamongdispatchers.html#BalanceRequestsAmongDispatchers