CPU service units
The CPU Service Unit (SU) is a conversion of the CMF CPU time using a conversion factor that is specific to the processor where the transaction is executed.
CPU service unit factors provide a standardized unit for measuring CPU consumption that allows for the inherent differences in processors. By specifying the CPU SU conversion factor in CICS PA, CMF CPU times can be converted to a common unit of measurement: service units. This allows you to more accurately compare workload performance when it is being performed on different processors, and to provide consistent measurement for SLA and chargeback.
Reporting with the CPUSU derived field
The derived field CPUSU is available in List, ListX, and Summary Forms and List and Summary Templates.You can report and extract converted values from HDBs either by specifying CPUSU in the Template and thereby loading it in the HDB or by specifying it in the Form. If the HDB is loaded with the CPUSU value, it will be reported and extracted as for any other field. In this case, the specification of the conversion factor in either the definition or file will be ignored. If on the other hand derived field CPUSU was not loaded into the HDB but is specified in the Form and the CPU field is in the HDB, the conversion factor will be used to calculate CPUSU value.
- Reporting CPUSU for a Summary HDB that was not loaded with the CPUSU value has a potential risk which might render the CPUSU value incorrect. This will occur when the summarized data in the HDB comes from Images with different CPU SU conversion factors. This means that a single CPU SU conversion factor does not apply to all transactions in the summarized data. To avoid this problem, ensure that all summarized transactions are eligible to use the same CPU SU conversion factor.
- The specification of the CPUSU value in functions such as Selection Criteria and Form Range must include a decimal point. Not specifying a decimal value will result in the value being interpreted as a decimal fraction.
Rules for applying conversion factors
CPU SU conversion factors can be specified in two places:- As an image-specific value defined in the repository (Definition)
- As a file-specific value specified in the CICSPA command suboperand SUFACTOR (File).
- File and Definition conversion factors cannot be combined in the execution of a single CICSPA command. If File conversion factors are specified, any Definition conversion factors are all ignored.
- File conversion factors are specific to each file and can be specified for individual IN ddnames or log stream names.
- If an IN ddname is a concatenation of multiple SMF files, the specified conversion factor will apply to all files in the concatenation.
- If multiple SUFACTOR operands refer to the same ddname or HDB name, only the first SUFACTOR conversion factor will be used for the input.
- If one or more file SUFACTOR values are specified then any ddname or input without an SUFACTOR takes the current processor default.
- In case of HDB reporting, the SUFACTOR will be available as an operand and will apply to all containers included in the report. In other words, there will not be a container-specific conversion factor specified or applied.