frank_vanderveken

Switching from IDMSINTL to IDMSINTC CICS interfaces

Discussion created by frank_vanderveken on Nov 14, 2014

Nowadays we (still) use the stabilized CICS IDMSINTL interfaces. We would like to introduce the standard IDMSINTC interfaces for some or
all CICS applications, since we would like to use some new features like threadsafe .

 

The System operations guide says the following about the difference/impact of using IDMSINTL or IDMSINTC :
"Because this (IDMSINTL) interface offers a minimal subset of the features available through the standard interface, its resource requirements are
therefore substantially reduced. Users with applications that demand no more than what this interface offers can use it in place of the standard interface
to reduce resource consumption in the CICS system. "

 

I conclude when reading above that introducing the standard interface can cause a substantial overhead ...

 

CA confirms the above. The v18 version of IDMSINTC has not been optimized enough to make the cpu usage and performance close to what
IDMSINTL provides, and recommend to clients that they benchmark both and decide if the difference in performance between the 2 interfaces is acceptable.

 

We plan to run some 'performance' tests to benchmark the impact of switching from IDMSINTL to IDMSINTC interfaces, and are currently looking
what factors to take in account to be able to perform tests as representative as possible.


Some of the open questions are among others :

  • Should we use a 'moderate' cics application, doing retrieval as well as update, or isn't that of any importance ?
  • Is it the amount of DMLs executed in the CICS application or the kind of DMLs that will be determinant to have an increased CPU usage when switching from
    IDMSINTL to IDMSINTC ?

 

Did anybody of the community members switched from IDMSINTL to IDMSINTC in the past ?
If so, can you join the results concerning 'overhead', and how the switch was implemented.
Please share ideas or remarks concerning the open questions we have ?

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