IBM OS Inter-transaction affinity, Transaction-system affinity, Affinity relations, Global, Bappl

Note that, if you are dynamically routing non-terminal-related START and DPL

requests, you should review your application to determine whether or not the

application is suitable for dynamic routing. The Transaction Affinities Utility cannot

detect affinities in these circumstances.

Inter-transaction affinity

Inter-transaction affinity is an affinity between two or more CICS transactions. It is caused by the transactions using techniques to pass information between one another, or to synchronize activity between one another, in a way that requires the transactions to execute in the same CICS region. Inter-transaction affinity, which imposes restrictions on the dynamic routing of transactions, can occur in the following circumstances:

vOne transaction terminates, leaving ªstate dataº in a place that a second transaction can access only by running in the same CICS region as the ®rst transaction.

vOne transaction creates data that a second transaction accesses while the ®rst transaction is still running. For this to work safely, the ®rst transaction usually waits on some event, which the second transaction posts when it has read the data created by the ®rst transaction. This synchronization technique requires that both transactions are routed to the same CICS region.

Transaction-system affinity

Transaction-system affinity is an affinity between a transaction and a particular

CICS region (that is, it is not an affinity between transactions themselves). It is

caused by the transaction interrogating or changing the properties of that CICS

region.

Transactions with affinity to a particular system, rather than to another transaction,

are not eligible for dynamic transaction routing. In general, they are transactions

that use INQUIRE and SET commands or, depend on global user exit programs.

Affinity relations

The affinity relation determines how the dynamic routing program selects a target

region for a transaction instance associated with the affinity. An affinity relation can

be classi®ed as one of the following:

Global

A group of transactions where all instances of all transactions in the group

that are initiated from any terminal must execute in the same target region

for the lifetime of the affinity. The affinity lifetime for global relations can be

system or permanent.

BAPPL

All instances of all transactions in the group are associated with the same

CICS BTS (Business Transaction Services) process. There may be many

different userids and terminals associated with the transactions included in

this affinity group.

LUname

A group of transactions where all instances of all transactions in the group

that are initiated from the same terminal must execute in the same target

region for the lifetime of the affinity. The affinity lifetime for LUname

relations can be pseudoconversation, logon, system, or permanent.

4 CICS Transaction Affinities Utility Guide