With z/OS V2R1, RMF Monitor III Data Gatherer (RMFGAT) can partially offload work to zIIP processors. zIIP exploitation helps customers reduce their total cost of ownership (TCO).
The RMFGAT zIIP exploitation is ON by default and can be turned OFF/ON dynamically by means of the ZIIPUSE/NOZIIPUSE parameter.
F RMF,F III,ZIIPUSE switches ON zIIP Usage
F RMF,F III,NOZIIPUSE switches OFF zIIP Usage.
Monitor III gatherer parmlib member ERBRMF04 is extended to contain the new options ZIIPUSE or NOZIIPUSE as well. The default is ZIIPUSE.
We tested this on a z/OS partition with online zIIP processors. We ran RMF Monitor III gatherer with ZIIPUSE and NOZIIPUSE options separately. We created a WLM report class for RMFGAT and produced an RMF Monitor I Workload Activity report to verify that a portion of RMFGAT processing was done on zIIP engines.
Here is a part of the report for the RMFGAT report class when running with ZIIPUSE for 30 minutes:
REPORT CLASS=RMFGAT ---SERVICE--- SERVICE TIME ---APPL %--- IOC 1982 CPU 85.721 CP 4.52 CPU 3273K SRB 1.500 AAPCP 0.00 MSO 0 RCT 0.000 IIPCP 0.13 SRB 56961 IIT 0.123 TOT 3332K HST 0.000 AAP N/A /SEC 1851 AAP N/A IIP 0.33 IIP 6.019
Please note that the IIP fileld represents the zIIP service time in seconds.
Here is a part of the report when running with NOZIIPUSE for 30 minutes:
REPORT CLASS=RMFGAT ---SERVICE--- SERVICE TIME ---APPL %--- IOC 1360 CPU 48.197 CP 2.73 CPU 1912K SRB 0.845 AAPCP 0.00 MSO 0 RCT 0.000 IIPCP 0.00 SRB 33364 IIT 0.075 TOT 1947K HST 0.000 AAP N/A /SEC 1082 AAP N/A IIP 0.00 IIP 0.000
This is one way you can verify that a portion of RMFGAT processing is indeed offloaded to zIIPs in your environment.