DB2 Version 9.7 for Linux, UNIX, and Windows
DB2 Version 9.7 for Linux, UNIX, and Windows
Arithmetic mean of the time between arrivals of coordinator activities at nesting level 0 associated with this service subclass or work class since the last reset. If the internally tracked average has overflowed, the value -2 is returned. For service subclasses, this monitor element returns -1 when COLLECT AGGREGATE ACTIVITY DATA for the service subclass is set to NONE or BASE. For work classes, this monitor elements returns -1 if no COLLECT AGGREGATE ACTIVITY DATA EXTENDED work action is specified for the work class. For workloads, this monitor element returns -1 when COLLECT AGGREGATE ACTIVITY DATA for the workload is set to NONE or BASE. Units are milliseconds.
For service classes, the inter-arrival time mean is calculated for service subclasses through which activities enter the system. When you remap activities between service subclasses with a REMAP ACTIVITY action, the coord_act_interarrival_time_avg of the service subclass you remap an activity to is unaffected.
| Event Type | Logical Data Grouping | Monitor Switch |
|---|---|---|
| Statistics | event_scstats | - |
| Statistics | event_wcstats | - |
| Statistics | event_wlstats | - |
Use this statistic to determine the arithmetic mean between arrivals of coordinator activities at nesting level 0 associated with this service subclass, workload, or work class.
The inter-arrival time can be used to determine arrival rate, which is the inverse of inter-arrival time. This average can also be used to determine whether or not the histogram template used for the activity inter-arrival time histogram is appropriate. Compute the average activity inter-arrival time from the activity inter-arrival time histogram. Compare the computed average with this monitor element. If the computed average deviates from the true average reported by this monitor element, consider altering the histogram template for the activity inter-arrival time histogram, using a set of bin values that are more appropriate for your data.