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Abstract
OMEGAMON IMS v550 ATF support of IMS FASTMON user exit - APAR OA60851
FASTMON is a new exit type introduced in IMS v15, as a high-performance alternative to the IMSMON type. The purpose of FASTMON is to significantly reduce the CPU overhead on monitoring IMS compared to IMSMON. The function of FASTMON is identical to that of IMSMON, except the fact that FASTMON is a Type-1 exit and therefore is not refreshable. Although both types are still supported, FASTMON is the preferred method when no REFRESH capability is required.
For Omegamon, the new FASTMON exit module KOIMONF0 is provided and should be used instead of KOIMON00.
Content
- IMS APAR PH24963 needs to be installed on the target IMS for ATF to take advantage of the new FASTMON exit.
- Omegamon APAR OA60851 needs to be installed in all RTEs.
- If the IMS FASTMON support is not installed or the Omegamon FASTMON exit is not defined to IMS, ATF will use the existing IMSMON exit KOIMON00, if defined.
- Modify the IMS PROCLIB member DFSDFxxx where the current ATF IMSMON exit is defined,
to replace the IMSMON with FASTMON definition (either delete or comment out the IMSMON line; the FASTMON exit name is KOIMONF0):
*------------------------------------------------------------*
* IMS USER EXITS
*------------------------------------------------------------*
<SECTION=USER_EXITS>
…
* EXITDEF=(TYPE=IMSMON,EXITS=(KOIMON00))
EXITDEF=(TYPE=FASTMON,EXITS=(KOIMONF0))
…
- Recycle IMS (because the FASTMON exit type is not refreshable)
Since the FASTMON exit is not refreshable, an IMS recycle is required for the installation.
The following new messages are added:
In IMS CTL region, to replace KI2A0010I for IMSMON:
KI2A0011I ATF FASTMON EXIT LOADED FOR IMSID=<imsID>
In Classic address space:
KI2A0030I ATF FASTMON EXIT FOUND: <exit header info> AT <address>
There are no other changes in operation
- When using ATF In high-workload environments (e.g., Production), we recommend to specify the trace option ‘Summarize Only = YES’ to minimize resource consumption (CPU, storage, DASD space), unless a detailed trace is necessary.
- Use filters and exceptions to eliminate unwanted transactions from traces and thus reduce the overhead.
- Stop ATF during periods when there are no active users and no tracing is needed. This will prevent unnecessary calls to the ATF FASTMON exit and thus reduce CPU overhead.
Stopping ATF: https://www.ibm.com/docs/en/om-ims/5.5.0?topic=facility-stopping-application-trace
- Ensure that the z/OS Service Class performance parameters for the Omegamon Classic started task are no lower than that of IMS.
Product Synonym
om/ims
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Document Information
Modified date:
04 August 2021
UID
ibm16478103