IBM OS manual Requesting region, Routing region, Target region

CICS Transaction Server for OS/390 Release 3 introduces extended dynamic

routing facilities, that allow the dynamic routing of:

v Transactions initiated at a terminal

v EXEC CICS START requests that are associated with a terminal

v EXEC CICS START requests that are not associated with a terminal

v Dynamic program link (DPL) requests that are received using:

± The CICS Web support

± The CICS Transaction Gateway

± External CICS interface (EXCI) client programs

± Any CICS client workstation products using the External Call Interface (ECI)

± Distributed Computing Environment (DCE) remote procedure calls (RPCs)

± Open Network Computing (ONC) RPCs

± Internet Inter-Object Request Block Protocol (IIOP)

± Any function that issues an EXEC CICS LINK PROGRAM request

v Transactions associated with CICS business transaction services (CICS BTS)

activities.

New terms have been introduced that describe the roles played by CICS regions in

dynamic routing:

Requesting region

The CICS region in which the dynamic routing request originates. For

transactions initiated at a terminal, and inbound client DPL requests, this is

typically a TOR. For terminal-related EXEC CICS START commands, for

non-terminal-related EXEC CICS START commands, for peer-to-peer DPLs,

and for CICS BTS activities, the requesting region is typically an AOR.

Routing region

The CICS region in which the decision is taken on where the transaction or

program should be run. For transactions initiated at a terminal, for EXEC

CICS START commands associated with a terminal, and for inbound client

DPL requests, this is typically a TOR. For non-terminla-related EXEC CICS

START commands, for peer-to-peer DPL requests, and for CICS BTS

activities, the routing region is typically an AOR.

Target region

The CICS region in which the transaction or program runs. For all

dynamically-routed requests, this is typically an AOR.

Full details about the new dynamic routing facilities are described in CICS

Intercommunication Guide.

The dynamic routing facility removes the need to specify the remote system name

of a target region in the transaction de®nition. Instead, you let the routing determine

dynamically to which target region it should route incoming transactions. Unlike

static routing, where there can only ever be one target region to which the routing

region can route a transaction, dynamic routing gives you the means to create

several target regions with the capability to process any given workload, and to let

the routing regions choose the best one from a candidate list.

2 CICS Transaction Affinities Utility Guide