IAMDRCC — CICS customization requirements

The IAMSAMP contains member IAMDRORG to help you define the necessary CICS resources for using the IAM Dynamic Reorg Utility. The IAMDRORG member contains CICS DFHCSDUP batch utility statements for defining the required resources. The IAMDRORG IAMSAMP member also contains comment statements to help guide you through the resource definition process.

The IAM Dynamic Reorg Utility makes use of the CICS EXCI batch job communication interface. If the CICS region that you plan on using the Dynamic Reorg Utility with, already has batch EXCI resources setup, then you will already have some of the required resources defined. The IAMSAMP member IAMDRORG comment statements will advise you accordingly in this regard.

At a minimum, you will need to define the following:

1. The IAM IDRS transaction that invokes program DFHMIRS, which has an assigned CICS Profile that has the INBFMH(ALL) attribute
2. The IAM Dynamic Reorg Server program- IAMDRCS
3. Add the IAM hlq.LOAD to your DFHRPL concatenation in your CICS startup JCL
4. Make sure that TDQUEUE(CSSL) is defined to CICS with maximum record length of 136. We recommend that you follow IBM requirements outlined in "CICS Transaction Server for z/OS. Resource Reference" (see section "Required TDQUEUE definitions")
   
   At a maximum you will also need to define the following:
   
   
5. A CICS Profile with the INBFMH(ALL) attribute
6. An EXCI Connection definition
7. An EXCI Sessions definition

Items 5 and 6 are part of the CICS delivered DFH$EXCI Group. If you have DFH$EXCI already included in one of your CICS startup lists, you might be all set. It is recommended that the EXCG Sessions definition have a RECEIVECOUNT of at least 18. The DFH$EXCI group that comes with CICS has an EXCG Sessions RECEIVECOUNT of 4, which would only allow for a maximum of two simultaneous dynamic file reorgs to run at a time and you may wish to run more than two at a time. To increase the RECEIVECOUNT to 18 or more you will need to copy the DFH$EXCI Group into a different Group, one that is in one of your CICS startup lists. Once the DFH$EXCI group elements are in a different Group, you will be able to alter the RECEIVECOUNT. The IAMDRORG IAMSAMP member contains the DFHCSDUP utility statements to accomplish this copy and alter.

The IAMDRORG IAMSAMP member also contains the CICS definitions required for running the IAMDRCC High Activity Toleration GLUE CICS exits. There are also definitions for a transaction and multiple programs for running a trace of the HAT exits, in case that ever becomes necessary for a problem solving situation.

Once you have made any changes to the IAMDRORG member in the IAMSAMP library, the example JCL to update CICS is also in the IAMSAMP as member IAMCSDUP. Revise that JCL as necessary for your installation, set the SYSIN DD to point to the IAMDRORG member, and submit the job.

Manually disabling HAT GLUE CICS exits

It is possible that under some problem scenario it may become necessary to manually disable the Dynamic Reorg High Activity Toleration (HAT) CICS GLUE Exits. To disable these exits manually use the CICS supplied CECI transaction. Commands for the two exits are as below -

There are times during the reorg process that only the IAMXDRFC exit is active, so if you get an error manually disabling the IAMXDRRW exit it is most likely because this exit is not active at the time.