Estimating the value of the PROCESS parameter in OPS/MVS
Article ID: 26084
Updated On:
Products
Issue/Introduction
What is the proper value for the OPS/MVS PROCESS parameter?
Environment
OPS/MVS
Resolution
The proper value to set for the PROCESS parameter, which also determines how many PROCESS BLOCKS to allocate at product initialization, varies from site to site. The default is the value of 30, when the PROCESS parameter is not specified in the OPSSPAxx initialization parameter list.
Tuning the subsystem after the initial startup can be performed by monitoring the OPS/MVS parameter value SSEXEXITHICOUNT, which can be viewed via the 4.1.1 OPSVIEW panel. Filter on this panel by entering SSEXEXIT in the NAME field. This will show other related relevant parameters including the HIGHDATE, HIGHTIME and FAILURES along with the HICOUNT. The HIGHDATE and HIGHTIME shows when the most recent spike in usage of the Process blocks occurred. This aids in determining, via debugging techniques using the OPSLOG for this time frame, what AOF rules or other OPS/MVS type of processing were in use, which may indicate the need to rework some of the automation in place to reduce this workload. If the SSEXEXITHICOUNT is equivalent to the PROCESS parameter value then could be the possibility of process block depletion, which could lead to automation processes or routines not functioning.
The PROCESS block uses private storage allocated to the product. The amount of storage obtained per process block allocated is dependent upon various parameter values set within the product, including the AOFMAXQUEUE, AOFSIZE, STACKMAIN and STACKERROR. Use the OPS/MVS Storage Simulation, Option 4.1.6 from the OPSVIEW Primary Options Menu, to see storage changes based on certain parameter changes. (OPSEXEC DD, library CCLXOPEX needs to be allocated to the TSO session for the user performing the analysis).
The 4.1.6 panel is a simulated storage usage display for OPS/MVS. Because this is a simulation panel, the OPS/MVS parameters can be manipulated without affecting the product, and there is no dynamic change made to the OPS/MVS address space from this panel. A common usage of this panel would be to change the PROCESS parameter value, and then note the type of impact this change has on the TOTAL value at the bottom of the panel. The goal would be to determine how much storage is available to this address space, represented at the bottom of the panel by the display only LIMIT parameter, which also represents the 2 gig storage available to any address space. This LIMIT value shows the storage available, and the TOTAL parameter is representative of that available amount in which OPS/MVS is grabbing. By changing the parameter values on this page, administrators can get an idea as to how much of the available storage might be consumed, and then use this as a comparison with the current values.
Note: The 4.1.6 panel is hidden, that is, if you reach the 4.1 panel you don't see the option 6. However, you type 6 and hit enter to access this panel.
Another thing to try is to set up a Time of Day rule to follow the process block activity.
For example:
PROCESS_HI = OPSPRM("SHOW","SSEXEXITHICOUNT")
PROCESS_USE = OPSPRM("SHOW","PROCESSUSE")
PROCESS_FAIL = OPSPRM("SHOW","SSEXEXITFAILURES")
A third approach to handle a shortage of process blocks is to monitor the following parameters:
PROCESSWAITMAXTIME=nnn - maximum wait time
PROCESSWAITCOUNT=nnn - number of times had to wait
PROCESSWAITTIMEOUT=nn - number of timeouts, i.e. process block fail.
PROCESSWAITAVG=nn - average time waiting, when no process block
is immediately available
If the number of timeouts related to the number of times it had to wait is low, then consider increasing the value of PROCESSMAXWAIT instead of increasing the value of the PROCESS parameter.
Additional Information
Feedback
