CICS® transactions and programs use many different techniques to pass data from one to another. Some of these techniques require that the transactions or programs exchanging data must execute in the same CICS region. This imposes restrictions on the regions to which transactions and distributed program link (DPL) requests can be dynamically routed and is said to create an affinity between them.
This guidance on affinity between transactions describes applications written using the EXEC CICS API. However, many of the comments are equally valid for Java™ applications executing in a CICSplex. For guidance on developing Java applications, see Java programming using JCICS.
Transactions, program-link requests, EXEC CICS START requests, CICS business transaction services (BTS) activities, and enterprise bean method calls can all be dynamically routed.
For detailed introductory information about dynamic and distributed routing, see Introduction to CICS dynamic routing .
The following sections talk exclusively about affinities between transactions.