Load balancing algorithms

You can select a round-robin algorithm or a biasing algorithm for load balancing. You select an algorithm using the Configuration Tool; see Configuring the Workload Manager.

The round-robin algorithm

The round-robin algorithm assumes that all CICS regions are equally valid for selection. In the round-robin algorithm, when the Client daemon is initially started, it reads from the configuration file a list of all possible CICS regions to which any ECI or EPI request can be sent.
The Workload Manager also records the last region selected. When a new ECI or EPI request is made, the next region in the list is selected as the target. When it reaches the last region it loops around to the first one.

The biasing algorithm

The biasing algorithm provides a way of balancing workload by specifying that workload distribution should favor particular regions. For example, if there are two regions with a bias of 75 and 25, program requests are sent in a ratio of 3:1 to the first region.
If a region fails, the internal biasing calculation changes. If two regions are available, one with a bias of 100 and the other with a bias of 0, all requests are sent to the first region. If the first region becomes unavailable, all requests are directed to the second region. A bias value of 0 is a special case, meaning use only if no other region is available.
The biasing algorithm works only for ECI calls. If you try to run an EPI application whilst the biasing algorithm is selected, the round-robin algorithm is used instead.