Application Migration Considerations › Application Migration Considerations › Runtime Configurations

Runtime Configurations

When load modules are the format of choice, you must also decide what sources to use to build the in-core LMT. You can find more information about the in-core LMT in the “Module Format for Programs and Panels” chapter.

There are three choices for building the in-core LMT:

• You can build the contents of the in-core LMT by extracting the data found only in the dictionary MODULE table. To implement this method, all modules must be created or identified. Specify IDOPTS LMTBLD=DD and the @ILMLIST must be empty.

  Advantages:

  DIS INDEX [ALL] MODULE is an accurate list of the programs and panels running in load module format.

  Disadvantages:

  If running multiple CICS regions against the same dictionary, LMT entries are built for programs and panels in all regions regardless of whether they run there.

• You can build the contents of the LMT by extracting the data only from the AMTs listed in the @ILMLIST. To implement this method, specify IDOPTS LMTBLD=NO. Dictionary entries might exist, but they are ignored when the LMT is initially built.

  Advantages:

  • You can customize the contents of the LMT to include only the programs and panels accessed in a particular region. This can be especially useful when multiple CICS regions run different sets of programs but share the same dictionary.
  • This method results in the quickest processing time to build the LMT because there is only access to the AMT modules, therefore access to the MODULE dictionary table was eliminated.
  • Minimal work is executed at each production center. You can create the modules in the development region along with an AMT and move it to the production center. This can be a very useful method of distributing programs in a vendor situation.
  • IDENTIFYs are optional.

  Disadvantages:

  • DIS INDEX MODULE is not an accurate list of the programs and panels running in load module format because it only references dictionary and not the LMT.
  • You cannot execute the REFRESH command if no dictionary module occurrence exists. The LMT entry is deleted.
• The contents of the LMT are built from both the programs found in the AMTs and the dictionary. Duplicates are allowed. However, they incur additional overhead when the in-core LMT is built. To implement this method, IDOPTS LMTBLD=DD and the @ILMLIST should not be empty.

  Advantages:

  • You can define applications common to all CICS regions in the dictionary.
  • You can define applications executed in one CICS region using an AMT.

  Disadvantages:

  • DIS INDEX MODULE is not an accurate list of the programs and panels running in load module format because it only references dictionary and not the LMT.
  • You cannot execute the REFRESH command if a dictionary module occurrence does not exist. The LMT entry is deleted.
  • Using the two methods together can be a source of confusion.