This document provides information on how to view and control data on zIIP processing.
See also Monitoring the Cache Usage in the section Print and Work File Caching.
You can use the Natural system command ZIIP
to determine whether the current Natural session is running on a zIIP and
analyze your CPU time savings by zIIP enablement.
The ZIIP command displays the number of GCPs
and zIIPs available in your z/OS environment, the CPU time consumed and,
optionally, a list of components that caused SRB/TCB switches: see the example
reports and explanations in zIIP Processing
Information and
zIIP Component
Switch Statistics in the System
Commands documentation.
For batch processing, you can also set the keyword subparameter
PRINT of
the profile parameter ZIIP to print zIIP processing
information automatically at the end of the session.
A report with general zIIP information and component switch statistics
is also printed when your CICS or Com-plete environment is shut down, depending
on the version of the Natural CICS Interface or Natural Com-plete/SMARTS
Interface, respectively, installed at your site. This report is similar to the
report produced by the PRINT option of the
ZIIP
system command. For a CICS environment, the required program definitions are
described in the section
Natural
zIIP Shutdown Statistics in Installing Natural
CICS Interface in the Installation for z/OS
documentation.
If you do not know how many zIIPs are available in your z/OS LPARs (logical partitions), you can check this with the following operator command:
D M=CPU
The following example result of this command shows that four GCPs
(00 to 03) and one zIIP (+I) is running
in the current LPAR, and that one additional GCP (05) and one
additional zIIP (-I) are defined as spare processors.
D M=CPU IEE174I 12.39.09 DISPLAY M 781 PROCESSOR STATUS ID CPU SERIAL 00 + 0FA10E2098 01 + 0FA10E2098 02 + 0FA10E2098 03 + 0FA10E2098 04 +I 0FA10E2098 05 - 06 -I
If you have the z/OS SDSF (System Display and Search Facility) installed under TSO, you can use the command ENC to obtain information about all WLM enclaves currently active in your z/OS environment and their zIIP usage.
For detailed information, see the IBM literature SDSF Operation and Customization.
Be aware that in the SDSF "D A" display the CPU time does not show the real values if running in a WLM enclave. You need to use the value of "ECPU Time" to evaluate the right CPU usage of your zIIP-enabled Natural session. The following definitions are quoted from the IBM z/OS SDSF documentation:
"CPU Time" is the CPU time (TCB + SRB) for the address space, excluding any NP-SRB/enclave time.
"ECPU Time" is the CPU time (TCB + SRB) for the address space, plus any NP-SRB/enclave time; that is, CPU used on behalf of this address space - the SDSF definition of "CPU Time".
Note:
Com-plete UQ A and Natural ISPF only document the
"CPU Time", there is no "ECPU Time" value
available.
You can evaluate the SMF type 30 records to obtain statistics about zIIP processing per address space. These records contain several fields with various job step CPU time values such as TCB, SRB, WLM enclave and zIIP times.
For detailed information, see the IBM literature z/OS MVS System Management Facilities (SMF).