Question & Answer
Question
Cause
Answer
CPUSU = CPU time * Conversion factor
CPU service unit reporting is only available in form-based transit reports.
Conversion Factor:
When IMS PA is running on the same system that generated the IMS log input file, the conversion factor can be calculated at run-time. Otherwise the conversion factor must be supplied to IMS PA in the command input.
IMS PA provides a REXX EXEC (member IPICPUSU in library SIPIEXEC) to generate the CPU time to Service Units conversion factor. You must execute this REXX on the same system that created the IMS log file. The command generated by this REXX is then input into the IMS PA batch process.
Note: There is no provision for specialty processors.
Output from REXX EXEC:
* IBM IMS Performance Analyzer: CPU time to Service Units conversion * * SYSID: XYZ1 * * CPU VV --ID-- Model Speed Specialty * 0 00 039A37 2818 1.000 * 1 00 039A37 2818 1.000 * 2 00 039A37 2818 1.000 zIIP * * Adjustment values: RMCTADJC=718 RMCTCPU=4097 * * Formula: SUSEC = 1000000 / (RMCTADJC * 256 / RMCTCPU) * Result : 1 CPU second = 22289.563 Service Units * * The following IMSPA batch command will convert CPU time to SUs: IMSPALOG SYSTEM(name,Vvrm,22289.563)
New form field CPUSU:
Field Name . . : CPUSU Source . . . . : IMS Description . . : CPU Service Units
The number of CPU service units consumed by the transaction. The service units are calculated by multiplying the CPU time (in seconds) by the processor-specific conversion factor.
The conversion factor for each IMS system should be specified in your batch JCL:
1. Use the IPICPUSU REXX EXEC located in the SIPIEXEC library to calculate the conversion factor and generate the batch command:
IMSPALOG SYSTEM(name,Vvrm,factor)
2. Specify the command generated by step 1 in your batch JCL, for example:
//IPIOPTS DD * * IMS System Definitions IMSPALOG SYSTEM(OLD1,V101,14637.212) IMSPALOG SYSTEM(NEW1,V121,CURRENT) /*
You can specify a factor of “CURRENT” to instruct IMS PA to calculate the conversion factor at run time, based on the processor where IMS PA is executing.
If you do not specify a conversion factor for an IMS subsystem to be reported then IMS PA will use “CURRENT”.
Batch command input:
The following JCL runs the LIST and SUMMARY form-based transit reports; where transaction CPU time and service units are both reported. There is one “IMSPALOG SYSTEM” command for each IMS subsystem. This is where the conversion factor is specified.
//IMSPA JOB (ACCOUNT),'NAME' //* //IMSPA EXEC PGM=IPIMAIN,PARM='V121' //STEPLIB DD DISP=SHR,DSN=IMSPA.V4R3M0.SIPILINK //SYSPRINT DD SYSOUT=* //LOLD1001 DD DISP=SHR,DSN=IMS.OLD1.SLDS //LNEW1001 DD DISP=SHR,DSN=IMS.NEW1.SLDS //IPIOPTS DD * * IMS System Definitions IMSPALOG SYSTEM(OLD1,V101,14637.212) IMSPALOG SYSTEM(NEW1,V121,22289.563) /* //IPICMD DD * IMSPALOG LIST(SECGROUP,FIELDS(TRANCODE,IMSID,RESPIMS,CPUTIME,CPUSU)) IMSPALOG SUMMARY(SECGROUP,FIELDS(TRANCODE,IMSID,RESPIMS,CPUTIME,CPUSU)) IMSPALOG EXECUTE /*
Note that the previous job can be split into 2 steps, one per IMS subsystem. In this case the two reports will have to be compared manually.
Report output:
The following transaction list report shows CPU time and service units together.
Proc IMS Resp CPU CPU Svc Trancode IMS ID Time Time Units BANK OLD1 2.629 1.880 28047 BANK NEW1 2.425 1.234 27505
While the CPU time for the same transaction running on two different systems shows a 52% improvement, in terms of service units the difference is only around 2%.
Requirements:
1. You must install APAR PM77790 PTF UK91303.
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Document Information
Modified date:
15 November 2020
UID
swg21643361