Upgrading a multi-region CICS EJB/CORBA server

To migrate a multi-region CICS EJB/CORBA server to CICS® Transaction Server for z/OS®, Version 3 Release 1, you can use any of the following methods:
  1. Shut down the server, upgrade all the regions, and restart the server.
    This approach is very similar to that described in Upgrading a single-region CICS EJB/CORBA server, except that:
    1. You must upgrade all the regions to CICS Transaction Server for z/OS, Version 3 Release 1 before restarting the server. Again, follow the standard migration procedures described in CICS Transaction Server for z/OS Migration from CICS TS Version version_number, where version_number is the version number of your back-level CICS release.
    2. You should refer to Setting up a multi-region EJB server, which describes in detail how to set up a multi-region EJB server in CICS TS for z/OS, Version 3.1.
    3. To republish the IORs of enterprise beans and stateless CORBA objects, issue a PERFORM CORBASERVER(CorbaServer_name) PUBLISH command on at least one of the AORs. Remember to issue a separate command for each CorbaServer in the AOR.

    The advantage of this approach is its relative simplicity, compared to solutions 2 and 3. Its main disadvantage is that the server's applications are unavailable during the upgrade process.

  2. Create a separate, CICS TS for z/OS, Version 3.1, logical server and gradually migrate applications from the old, back-level, server to the new one.
    The advantages of this approach are:
    1. Applications are kept available throughout the upgrade process.
    2. You can start with a minimal CICS TS for z/OS, Version 3.1 server, perhaps consisting of just two regions—one listener and one AOR. As more applications are migrated, you can expand the CICS TS for z/OS, Version 3.1 server and simultaneously reduce the number of regions in the back-level server, thereby conserving resources.
    3. It is probably easier to implement than solution 3.

    To set up a new CICS TS for z/OS, Version 3.1 multi-region EJB server, follow all the steps in Setting up a single-region EJB server and Setting up a multi-region EJB server.

  3. Perform a "rolling upgrade".

    In a "rolling upgrade", one region at a time is upgraded from the previous to the current level of CICS, while keeping the server operational.

    The advantages of this approach are:
    1. Applications are kept available throughout the upgrade process.
    2. Unlike solution 2, at no stage is it necessary to set up additional CICS regions.

    This method is described in detail in Performing a "rolling upgrade".