Application Migration Considerations › Application Migration Considerations › Replacing Online Applications › Replacing Programs and Panels in an Active Online Environment

Replacing Programs and Panels in an Active Online Environment

You can choose among five basic configurations options to process a single environment.

Option 1: Load Modules - LMTBLD=DD with empty @ILMLIST

This represents the traditional method used in past releases of CA Ideal before AMTs became available with CA Ideal 2.2. Using this option requires that the modules be defined to the dictionary. You can do this by CREATing the modules in the production center from the VLS object or moving the modules and issuing an IDENTIFY command for each program or panel.

The syntax of the CREATE and IDENTIFY command are described in the Command Reference Guide. You must execute the commands in batch.

Since the CREATE and IDENTIFY commands do not update any in-core module table, the new or updated modules are not known to any online line CA Ideal environments in operation when the commands are executed. After the load modules and dictionary entries are defined to the region, you can disable the application and refresh each of the new or replaced programs and panels before they are disabled. Waiting to recycle the region is also an optional means of bringing in the new application.

Option 2: Load Modules - LMTBLD=NO, without dictionary entries

This setup means the LMT is built only from the entries pointed to by @ILMLIST. By including an AMT in the same library as the application load modules, it is only necessary that the target site include the name of the AMT in the @ILMLIST module.

This method requires careful consideration when you attempt to replace modules in an active online environment. Because there are no MODULE dictionary entries for any of the programs or panels when using this method, the REFRESH command deletes the LMT entry and does not perform the NEWCOPY.

If it is necessary to bring in new programs, panels, or applications, you can issue IDENTIFY commands in batch for each of the entities that need to be activated. Once that is complete, you can REFRESH each entity so that the LMT entries are built. You can then DELETE each module. Be sure to make the necessary modification to the AMT and @ILMLIST so that the LMT is built correctly when CICS is recycled at a later time.

Existing programs and panels in load module format can be CICS NEWCOPIED to bring in new versions. Always remember to NEWCOPY all three modules associated with a program if you select this method. You can also IDENTIFY and REFRESH the modules if you do not want to use the CICS NEWCOPY commands and optionally DELETE the modules, depending on whether you want to maintain any module entries in the dictionary.

If it is not necessary to add a new program, panel, or application to the environment while CICS is up; consider disabling the REFRESH command to avoid LMT entries from accidental deletion. Disabling the REFRESH command eliminates the ability to add a new program or panel to the environment while CICS is active. Any new programs and panels must be added to an AMT. You must add new AMT names to @ILMLIST. A recycle of CICS must be performed for the changes to become active. NEWCOPYing an AMT and @ILMLIST has no effect on the in-core LMT while CICS is up.

If the REFRESH command is erroneously executed, it can delete the program or panel from the LMT. If this occurs, execute the IDENTIFY command in batch and the affected application is disabled before the REFRESH is executed again. Although you are executing load modules in this environment, DISPLAY INDEX MODULE does not return an index of modules. Remember that this command is a listing according to the dictionary.

Option 3: Load Modules - LMTBLD=DD and entries in @ILMLIST

This setup builds the LMT from two sources. It is important to only issue REFRESH commands for those entities that exist in the dictionary. Programs and panels that are only defined to an AMT are deleted.

Option 4: Load Modules - LMTBLD=NO with dictionary entries

This setup implies that you are building the in-core module table from the entries pointed to by @ILMLIST, but still maintaining the dictionary MODULE occurrences. The dictionary entries let you execute the REFRESH command in CA Ideal without having the adverse effect of deleting the LMT entry.

Option 5: VLS format only or with load modules

You can run load modules with one of the four options previously mentioned and you can run some of your programs in VLS format.

You should be aware of the following enqueuing considerations if you plan to replace VLS format programs in an active online environment.