Incorporating Mainframe in the SOA Architecture

From my point of view the mainframe is very similar to incorporating a service interface on most other existing IT investments.  The common primary objective is to extend the reach and reuse of key data and business logic from the mainframe to other applications and business processes such as trading partner interactions over the internet, business-to-customer portals and business intelligence applications like dashboards and data marts.

My approach is to use a message-oriented middleware (MOM) or message queue (MQ) to act as a network protocol and data payload "bridge" between the mainframe and an established service interface which is implemented on an intermediary SOA Expressway or other application server.   The main advantages are that this type of architecture supports reliable messaging to protect messages from loss, works well in asynchronous integration patterns, and can be effectively triggered through event-driven transactions.  However, the extra middleware (MOM / MQ) is a fairly substantial performance overhead, so for high volume and low latency data exchanges this approach can cost significant budget to scale.