The Workload Manager dispatcher technology introduced in DB2 10.1 offers a powerful and simple interface for controlling CPU. The two controls used to provide direction to the WLM dispatcher are CPU limits and CPU shares. Ever wonder how to choose between them?
We are collecting statistics every two minutes but looking at the CoordActLifetime histogram data collected in one of these 2 minute windows, we observed that in the upper bins, there are activities with lifetimes of 1715085 milliseconds (@28 minutes). How is this possible?
I am running DB2 with the connection concentrator active and there is a time-spent monitor element, agent_wait_time, to account for the time spent waiting for an agent. I'd like to know if this time is included in the activity lifetime histogram?
One of the more interesting parts (to me :) of the new monitoring information introduced in DB2 for LUW 9.5 is the histogram concept. This beastie provides useful information about the distribution of values for different characteristics of things going on within DB2.
A recent customer PoC revealed some confusion about how CPU shares interact when they are defined at both the service superclass and subclass levels in an environment with multiple service classes defined.