Larry Lawler LARRY LAWLER
CTO

Company—

Unicom Global

Years in IT—

40 years

My first mainframe job—

PL/I programmer and  CICS SysProg at Manitowoc Engineering, in Manitowoc, Wisconsin

My favorite mainframe memory—
My favorite memory was working with IBM’s Plan Code product and trying to figure out why it consumed so much CICS resources.

After sitting with the assembler listing for DFHFCP, I discovered “locate” mode with a following “release” was being converted into VSAM ENDREQ macros VSAM ENDREQ macros flush data and Index buffers, as part of releasing ownership of the PLH or String.

So we found the IBM-supplied optional source code in a DR vault, and patched two lines of code to use “move mode” instead of “locate mode” DFHFC requests.

Next we called the user and asked the user to test it for us, to see if there were any improvements. While still on the phone the user said it must have failed as it is done already. A couple minutes later, the user called back to say it worked perfectly in 2 minutes, instead of the normal 4.5 hours. At that point I was hooked on CICS and VSAM tuning.
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