CPU: Latent Demand
Latent demand represents the work that is waiting to be dispatched on a CP where all of the other CPs are currently busy. This report shows you which systems are overloaded and, as a result, could potentially slow down your high-priority applications. The report allows you to be proactive and reroute this work to less-utilized systems for faster processing.
Using this report, you can see the In-and-Ready Count and the Capture Ratio for a system. When the In-and-Ready Count exceeds the number of logical processors that are assigned to a system, then you have latent demand because work is waiting to be dispatched to a CP that is not already busy.
Figure 1. Latent Demand example
- Source tables
- [Presentation View].[z/OS System Level Metrics]
- [Presentation View].[WLM Service Class Period Usage/Delay Metrics]
- Drill through to the following reports
- WLM: Delays by Importance Level
- Standard prompts:
- date range
- time range
- interval band
- show
- Report-specific prompts
- system
- importance level
This report contains the following information:
- system
- The z/OS system id.
- importance level
- The WLM importance level that is assigned to a service class period.
- processor type
- The engine type: CP, zIIP, zAAP.
- AVG # OF ADDRESS SPACES WAITING
- The weighted average number of address spaces that are swapped in and ready to be dispatched.
- CPU DELAY COUNTS
- Number of CPU delay samples. Calculated as the sum of R723CCDE.
- AVG of CP WORK UNITS
- Average number of work units for general-purpose processors over the interval. Calculated as the average of SMF70CTT.
- AVG of zIIP WORK UNITS
- Average number of work units for zIIP processors over the interval. Calculated as the average of SMF70ETT.
- AVG of zAAP WORK UNITS
- Average number of work units for zAAP processors over the interval. Calculated as the average of SMF70DTT.
- MAX of CP WORK UNITS
- Maximum number of work units for general-purpose processors over the interval. Calculated as the minimum of SMF70CMM.
- MAX of zIIP WORK UNITS
- Maximum number of work units for zIIP processors over the interval. Calculated as the minimum of SMF70EMM.
- MAX of zAAP WORK UNITS
- Maximum number of work units for zAAP processors over the interval. Calculated as the minimum of SMF70DMM.
- AVG# of WORK UNITS WAITING
- The weighted average number of any work is queued and waiting to be processed.
- ONLINE PROCESSORS
- The number of engines online to a system on which work can be dispatched.