The distributed model

The distributed model is a peer-to-peer system. Each participating CICS® region can be both a routing region and a target region. A routing program runs in each region.

Figure 1 shows a distributed routing model. Four CICS regions are connected to each other. A distributed routing program runs in each region. Each region may be a requesting region, routing region, or target region.
Figure 1. Dynamic routing using a distributed routing model
The picture shows four CICS regions. Each region is connected to all the other regions. A distributed routing program runs in each region. Each region may be a requesting region, routing region, or target region. It is a peer-to-peer model.
The distributed model applies to the routing of the following:
  • CICS business transaction services processes and activities
  • Non-terminal-related START requests
  • CICS web service requests

Advantage of the distributed model

There is no single point-of-failure.

Disadvantages of the distributed model

  • Compared to the hub model, there are a great many inter-region connections to maintain.
  • You may have problems with distributed data. For example, any data used to make routing decisions must be available to all the regions. (CICSPlex® SM solves this problem by using dataspaces.)