Running C:D Plex with Extended Recovery

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C:D Plex, when configured correctly, should allow the active manager and active servers to be taken down, allowing the standby manager and standby servers to then come up and become active. If the active and standby managers and servers are on separate LPARs, this means C:D Plex can be brought down with the standby then coming up and the first LPAR re-IPLed without any appreciable loss of processing or threat of missing SLAs.

To do this correctly, 

In setting up an active C:D Plex with ManagerA and servers Server1A and Server2A with standby C:D Plex with ManagerB and servers Server1B and Server2B:

In the JCL for the Manager, there is the following:

       //CDPLEX    DD  DSN=$hlq.PARMLIB(MANAGERA),DISP=SHR

where the member MANAGERA is the C:D Plex initparms for the CDPlex ManagerA.

In this member MANAGER in the $hlq.PARMLIB, there is the following:

     CDPLEX.SERVER.JOBDSN=$CD.HOST5200.JCL
     CDPLEX.SERVER.JOBMEM=((CDSRV1A,SERVER1), -
                                                     (CDSRV2A,SERVER2)) 

CDPLEX.SERVER.JOBSDN is the dataset where the JCL members are located that start the servers. 

CDPLEX.SERVER.JOBMEM has two parameters for each server defined in the C:D Plex:

     (1) CDSRV1 is the name of the JCL (job) member in the dataset defined by CDPLEX.SERVER.JOBDSN

     (2) SERVER1 is the C:D server name that is defined in the C:D Plex initparms for Server1 for parameter CDPLEX.SERVER.

This means that JCL job $hlq.PARMLIB(CDSRV1A) is submitted that will start the server SERVER1A and $hlq.PARMLIB(CDSRV2A) will start server SERVER2A.

In the C:D Plex initparms for Server1A, it should have at least the following:

     CDPLEX.MANAGER=NO          
     CDPLEX.SERVER=SERVER1

Server2A will have CDPLEX.SERVER=SERVER2 defines, etc..

When using extended recovery in a C:D Plex, both the active and standby servers will use the same C:D Plex initparms. That is, Server1A and Server1B both use SERVER1 initparms, etc. This means that whether Server1A or Server1B is running, the C:D Plex server name will be SERVER1, Server2A or Server2B will be SERVER2, etc..

However, the active and standby Managers each need their own set of C:D Plex initparms to define which JCL jobs for which servers will be run when that particular Manager is active.

So in PARMLIB member MANAGERA (active), the following is defined:

     CDPLEX.SERVER.JOBDSN=$CD.HOST5200.JCL
     CDPLEX.SERVER.JOBMEM=((CDSRV1A,SERVER1), -
                                                     (CDSRV2A,SERVER2))  

In PARMLIB member MANAGERB (standby), the following is defined:

     CDPLEX.SERVER.JOBDSN=$CD.HOST5200.JCL
     CDPLEX.SERVER.JOBMEM=((CDSRV1B,SERVER1), -
                                                     (CDSRV2B,SERVER2)) 

NOTE: Very Important - the server names (second parameter for each server) defined in both MUST be the same. So Sever1A and Server1B both have SERVER1, Server2A and Server2B both have name SERVER2, etc..

In the JCL for the active ManagerA, you would have:
//CDPLEX    DD  DSN=$hlq.PARMLIB(MANAGERA),DISP=SHR

then in the JCL for the Standby ManagerB, you would have:
//CDPLEX    DD  DSN=$hlq.PARMLIB(MANAGERB),DISP=SHR

By doing this, it causes the standby Manager to start the standby servers instead of restarting the primary servers.

Then, you can go to the ADMIN;SN panel in the IUI and bring down the C:D Plex (specifying Recovery YES) or issue the following from the command line in SDSF:

     F CD1MGR,STOP,CDPLEX,RECOVER

and the primary ManagerA with servers Server1A and Server2A will be brought down and the standby ManagerB and standby servers Server1B and Server2B will then come up and become active.