Example

An example of establishing connections between CICS® TS for z/OS® generic resources.

In Figure 1 through Figure 4, each generic resource uses the partner sysplex's generic resource name when initiating a connection. All generic resource members are able to initiate connections; that is, they all have a generic resource name connection (a predefined connection entry in which the NETNAME is the generic resource name of the partner sysplex). The connections are APPC parallel-session synclevel 2 links.
Figure 1. The figure shows two sysplexes, SYSPLEXL and SYSPLEXR. Each contains a CICS generic resource group. The CICSL1 member of the CICSL group attempts to acquire a connection to a member of the CICSR group in SYSPLEXR.
The picture shows the flows described in the text. It shows shows two sysplexes, SYSPLEXL and SYSPLEXR. SYSPLEXL contains a generic resource group called CICSL. SYSPLEXR contains a generic resource group called CICSR. This is the first flow: from the CICSL1 member of the CICSL group to the CICSR1 member of the CICSR group in SYSPLEXR. The predefined connections for the generic resource names CICSR and CICSL in CICSL1 and CICSR1 are used.

In Figure 1, the first bind that flows from CICSL1 to CICSR is routed to whichever member of CICSR z/OS Communications Server decides is the most lightly loaded. In this example it goes to CICSR1. The predefined connections for the generic resource names CICSR and CICSL in CICSL1 and CICSR1 are used.

Affinities are created at SYSPLEXL and SYSPLEXR, associating CICSL1 with CICSR1. When you need to end these affinities, you may or may not need to do so explicitly—see Ending affinities and APPC connection quiesce processing. Until the affinities are ended, whenever CICSL1 tries to reconnect to CICSR, z/OS Communications Server routes the request to CICSR1; and whenever CICSR1 tries to reconnect to CICSL, z/OS Communications Server routes the request to CICSL1.

Figure 2. Second flow, CICSL2-CICSR
The picture shows the flows described in the text. It shows shows two sysplexes, SYSPLEXL and SYSPLEXR. SYSPLEXL contains a generic resource group called CICSL. SYSPLEXR contains a generic resource group called CICSR. This is the second flow: from the CICSL2 member of the CICSL group to the CICSR1 member of the CICSR group in SYSPLEXR. In CICSL2, the predefined connection for CICSR is used. In CICSR1, the predefined connection entry for CICSL is already in use, so a new connection is autoinstalled using the member name CICSL2.

Figure 2 shows a bind flow from CICSL2 to CICSR. In this example z/OS Communications Server has, once again, chosen to route it to CICSR1, but it could have gone to one of the other members of CICSR.

The predefined connection for CICSR in CICSL2 is used. CICSR1 looks for the connection entry for CICSL. It is already in use, so a new connection is autoinstalled using the member name CICSL2.

Affinities are created at SYSPLEXL and SYSPLEXR, associating CICSL2 with CICSR1. If you need to end these affinities, you may or may not need to do so explicitly.

Figure 3. Third flow, CICSR1-CICSL
The picture shows the flows described in the text. It shows shows two sysplexes, SYSPLEXL and SYSPLEXR. SYSPLEXL contains a generic resource group called CICSL. SYSPLEXR contains a generic resource group called CICSR. This is the third flow: from the CICSR1 member of the CICSR group in SYSPLEXR to the CICSL group in SYSPLEXL. The existing affinity forces it to CICSL1.

Figure 3 shows a third flow, this time from CICSR1 to CICSL. The existing affinity forces it to CICSL1.

Figure 4. Fourth flow, CICSR2-CICSL
The picture shows the flows described in the text. It shows shows two sysplexes, SYSPLEXL and SYSPLEXR. SYSPLEXL contains a generic resource group called CICSL. SYSPLEXR contains a generic resource group called CICSR. This is the fourth flow: from the CICSR2 member of the CICSR group in SYSPLEXR to the CICSL group in SYSPLEXL. It can go to any member of CICSL, but in this example z/OS Communications Server routes it to CICSL2.

Figure 4 shows a fourth flow, this time from CICSR2 to CICSL. It can go to any member of CICSL, but in this example z/OS Communications Server routes it to CICSL2.

The predefined connection entry for CICSL in CICSR2 is not in use and so it is used now. CICSL2 looks for the predefined connection entry for CICSR. It is in use, and so an entry for CICSR2 is autoinstalled.

Affinities are created at SYSPLEXL and SYSPLEXR, associating CICSL2 with CICSR2. If you need to end these affinities, you may or may not need to do so explicitly.