Improved Debugging for IMS Message Processing Programs

Although we publish that we can debug IMS/MPPs in an IMS Message Processing Region, we really do not have a viable solution to debug programs in an IMS MPP environment. If a customer has Xpediter/IMS, and wants to use Debug Tool to replace this function, we do not have a solution. The only way to do this is with BTS, but they may have to purchase this product to do so.

We provide LE exits to enable a debugging session with MPRs. However, many factors must be set to allow Debug Tool to trigger consistently, and to allow other programs to run in the IMS environment. These factors are not documented in the Debug Tool publications. When I received the information from the Debug Tool team, the requirement to use SCHDTYPE=PARALLEL is met with resistance. I found that most customers use SCHDTYPE=SERIAL with the DOPT parameter, which allows ACB generation to be performed while the online IMS System is running. You can not specify SCHDTYPE=PARALLEL with the DOPT option.

In our last account the customer developed tools to the the same as what other ISVs do - Create a different transaction class for the transaction which is needed to be debugged, and start another MPR with the new transaction. This allows the other transactions with the same transaction class to run when SCHDTYPE=SERIAL is used. The customer created a panel that collects the name of the existing MPR, to use the same files, the transaction name, and then proceeds to create a batch job that performs the following steps:
1) Issue a command to determine the transaction class of the transaction requested, and capture this information.
2) Assign the transaction class to another number for debugging. Note, there may be many transaction classes required for debugging, specifically one for each Debugging MPR that will be created.
3) Start the new MPR with a different job name, and include the library with the LE options linked with the EQAD3CXT LE exit.
4) When the region is terminated, re-assign the transaction back to the original class.

In summary, this requirement is to:
a) Define all the IMS parameters required for the SCHDTYPE=PARALLEL or SERIAL in the Debug Tool publications.
b) For SCHDTYPE=SERIAL, provide tools to create an MPR to set the transaction class as described above.

Note, the above solution does NOT allow concurrent debugging of a transaction. It allows other transactions to continue to run that have the same transaction class. This restriction is also part of other ISV solutions.

In addition to providing the above solution, the panel that is used to save the LE options (xxxx.DBGTOOL.EQAOUPTS) should be incorporated into this solution. In other words, it does not make sense to collect program names to be debugged when we are collecting the transaction name(s) to debug. For this invocation, the panel should be modified to include multiple IMS transactions, but no programs to debug. This modified version of the panel can be included in the same process as described to collect the information to invoke the Debug Tool MPR.