z/OS capture ratios Velocity Software, Inc. Velocity Software, Inc. is recognized as a leader in the performance measurement of z/VM and Linux on z. The Velocity Performance Suite consist of a set of tools that enable installations running z/VM to manage Linux and z/VM performance. In addition, many components of server farms can be measured and analyzed. Performance data can be viewed real-time through the use of either 3270 or a browser. The CLOUD Implementation (zPRO) component is designed for full cloud PaaS implementation as well as to extend the capabilities of the z/VM sysprog (system programmer) to the browser world. This feature moves system management to the point-and-click crowd. Archived data and reports can be kept available of long term review and reporting usine zMAP. The zVPS, formally ESALPS, components consist of: zMON (formally ESAMON - real-time display of performance data), zTCP (formally ESATCP - SNMP data collection), zMAP (formally ESAMAP - historical reporting and archiving), zVWS (formally ESAWEB - z/VM based web server), zTUNE (a subscription service), zVIEW (formally SHOWCASE - web based viewing of performance data), zPRO (new to the quality line of Velocity Software Products). Velocity continues to work with other software vendors to ensure smooth interface with or from other products such as VM:Webgateway, CA-Webgateway, EnterpriseWeb, MXG, MICS. Velocity software remains the leader and inovator in the z/VM performance, Linux performance, Managing cloud computing arenas.
About Us | Products | FAQ | zVIEW Demo | zPRO Demo | Customer Area | Education | Linux Hints & Tips | Presentations | News | Industry and Events | Employment Opportunities
Home | Contact Us | License Info | Newsletter    

z/OS CPU Capture ratios using zOSMON

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 Capture Ratio

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.



Don't miss Velocity Software's Performance Seminars