Capture ratios are used to both validate the data model by having multiple data sources that should agree, and in determining that there is something missing. This document will describe both from a general purpose engine how capture ratio is determined, and for an SMT engine. Velocity Software's work with IFLs with SMT over many years provides some experience that passes on to analyze zIIPs running SMT.
As the pricing of a GP is so significantly more than that for zIIPs or other specialty engines, we do not believe in combining numbers and coming up with just "the number" for the system. Thus, we will describe analysis of GP an of zIIPs independently.
To show 100% capture ratio, meaning we can identify all of the
CPU consumption, the following is a good place to strt:
Capture ratio = (system work + user work) / total CPU consumption
The unidentified CPU consumption is uncaptured by z/OS and is
usually identified as system paging or other system work.
On the ZOSCPU report, it shows LPAR by LPAR the CPU consumption by processor - and totals as reported in the SMF 70 record. Everything is in absolute percent, meaning that the 71.4 percent CPU utilization in theory could go up to 200% in this LPAR that has two GP virtual processors assigned.
Report: ZOSCPU Z/OS CPU Report
Monitor initialized: 10/01/20 at 11:52:00
--------------------------------------------
TIME/ <--CPU--> Sample <-CPU Utilization>
SYSID ID Type Count Total Wait Parked
------ ---- ---- ----- ----- ----- ------
10/01/20
11:52:00 - 11:53:00
VSI1 Tot GP 2 71.4 62.4 0
0 GP 1 41.8 25.1 0
1 zIIP 1 0.0 99.9 0
2 GP 1 29.6 37.4 0
The CPU consumed by the produciton work is reported on the ZOSJCPU (Job CPU) report. Looking at the totals line gives the "total" CPU consumption as a percent of a CPU.
The job cpu is a summary of all jobs during that interval that were either in progress or terminated, of the following fields:
Report: ZOSJCPU z/OS Job/Step CPU/Resource Report
Monitor initialized: 10/01/20 at 11:52:00 on Z15S serial 050F78
-----------------------------------------------------------------
SYSID <------JOB----------> <-------CPU Percents---------------->
Name JobID Step Initiat Regn
Nbr Total STD SRB TCB SRB I/O Cntrl USS
---- -------- -------- --- ----- ---- ---- --- --- --- ----- ---
10/01/20
11:52:00 - 11:53:00
VSI1
Totals . 67.3 58.4 8.4 0 0 0.4 0 0.0
CICSJZ1 STC02134 1 33.8 32.5 1.3 0 0 0.0 0 0
CICSJZ2 STC08678 1 23.3 22.2 1.0 0 0 0.0 0 0
IXGLOGR IXGLOGR 1 0.1 0.0 0.1 0 0 0 0 0
IZUSVR1 STC08654 3 0.1 0.1 0 0 0 0 0 0.0
JES2 JES2 1 0.3 0.3 0.0 0 0 0.0 0 0
JES2MON JES2MON 1 0.1 0.1 0.0 0 0 0 0 0
MSTJCL00 MSTR 1 0.0 0.0 0.0 0 0 0 0 0
OMVS OMVS 1 0.1 0.1 0 0 0 0 0 0
RMF STC08625 1 0.1 0.1 0.0 0 0 0 0 0
SDSF STC08631 1 0.0 0.0 0.0 0 0 0 0 0
SDSFAUX STC08645 1 0.1 0.1 0.0 0 0 0 0 0
SMF SMF 1 0.1 0.1 0.0 0 0 0 0 0
SMS SMS 1 0.0 0.0 0 0 0 0 0 0
TCPIP STC08627 1 1.9 0.3 1.6 0 0 0 0 0.0
TN3270 STC08659 1 4.2 0.0 4.1 0 0 0 0 0
WLM WLM 1 0.3 0.2 0.1 0 0 0 0 0
XCFAS XCFAS 1 0.1 0.1 0.0 0 0 0 0 0
ZFS STC08623 1 0.2 0.2 0.0 0 0 0 0 0
ZOSMNVC1 STC08663 1 0.5 0.5 0 0 0 0 0 0
ZOSMNVM2 STC02484 1 0.5 0.5 0 0 0 0 0 0
ZOSMNVM4 STC02485 1 0.5 0.5 0 0 0 0 0 0
ZOSMONTK JOB08811 1 0.4 0.4 0 0 0 0 0 0
Capture ratio then is the totals from the ZOSJCPU (67.3) divided by the total GP time for the LPAR (71.4) or about a 94% capture ratio.
The ZOSSUM report was created to provide a quick analysis of the capture ratio analysis.
Report: ZOSSUM z/OS CPU Summary Report Velocity Software
Monitor initialized: 10/01/20 at 11:52:00 on Z15S serial 050F78
---------------------------------------------------------------------------------
SYSID SYSPLEX <-Physical Processor-> Capt <---Job CPU Percents (GP) ---------->
Name <-CPU Utilization> CPU Ratio Initiat
Total Wait Parked Cnt Total STD SRB TCB SRB I/O Cntrl USS
---- -------- ---- ----- ------ --- ----- ----- ---- ---- --- --- --- ----- ---
11:53:00 - 11:54:00
VSI1 VSIPLEX 71.2 68.8 0 2 94.0 67.0 58.0 8.5 0 0 0.5 0 0.0
V24A VSIPLEX 47.8 35.0 0 2 94.4 45.1 43.7 1.3 0 0 0.1 0 0
---------------------------------------------------------------------------------
11:54:00 - 11:55:00
VSI1 VSIPLEX 70.2 70.2 0 2 93.7 65.8 57.0 8.3 0 0 0.4 0.0 0.0
V24A VSIPLEX 48.2 33.6 0 2 95.9 46.3 44.9 1.3 0 0 0.1 0.0 0
---------------------------------------------------------------------------------
11:55:00 - 11:56:00
VSI1 VSIPLEX 70.4 61.1 0 2 94.3 66.4 57.6 8.4 0 0 0.4 0 0.0
V24A VSIPLEX 47.2 35.0 0 2 94.2 44.4 43.2 1.2 0 0 0.1 0 0
zIIP engines are significantly cheaper than full blown z/OS engines, with the objective of using them as much as possible to offload the GP engine to the cheaper processor.
For measuring zIIP CPU Consumption there are 3 values:
These values are reported on the ZOSJCPU report.
Report: ZOSJCPU z/OS Jobe ZMAP 5.1
Monitor initialized: 10/01/20
-----------------------------------------
SYSID <------JOB----------> . <-ZIP Pct->
Name JobID Step .
Nbr . Tot Enc Dep
---- -------- -------- --- . --- --- ---
10/01/20 .
11:52:00 - 11:53:00 .
VSI1 .
Totals . . 0.0 0 0
CICSJZ1 STC02134 1 . 0 0 0
CICSJZ2 STC08678 1 . 0 0 0
IXGLOGR IXGLOGR 1 . 0 0 0
IZUSVR1 STC08654 3 . 0.0 0 0
JES2 JES2 1 . 0 0 0
JES2MON JES2MON 1 . 0 0 0
The zIIP information is also summarized in the ZOSSUM report. In this case with no activity, it is not so interesting.
Report: ZOSSUM are Corporate ZMAP 5.1.1 10/10 Monitor initial ----------------------------------------------- SYSID SYSPLEX <--zIIP-->Name CPU Capt Pct Ratio Totl Depnd ---- -------- ---- ----- ---- ---- ----- 11:53:00 - 11:5 VSI1 VSIPLEX 0.0 0 0 0 0.0 V24A VSIPLEX 0.2 0 0 0 0.0 ----------------------------------------------- 11:54:00 - 11:5 VSI1 VSIPLEX 0.1 0 0 0 0 V24A VSIPLEX 0.1 0 0 0 0.0 ----------------------------------------------- 11:55:00 - 11:5 VSI1 VSIPLEX 0.0 0 0 0 0 V24A VSIPLEX 0.1 0 0 0 0
When we get some good zIIP usage, we will revisit the capture ratio. But as z/OS system work would not run on the zIIPs, it should be expected the capture ratio is 100% with nothing missing.
