A company runs several instances of multi-threaded application that requires virtual machine to be configured with multiple vCPUs.
Which metric is checked to determine if CPU contention exists on an ESXi 5.x host?
The percentage of time the world spent in wait state.
This %WAIT is the total wait time. I.e., the world is waiting for some VMKernel resource. This wait time includes I/O wait time, idle time and among other resources. Idle time is presented as %IDLE.
The percentage of time the world was ready to run.
A world in a run queue is waiting for CPU scheduler to let it run on a PCPU. %RDY accounts the percentage of this time. So, it is always smaller than 100%.
+Q: How do I know CPU resource is under contention?+
+A: %RDY is a main indicator. But, it is not sufficient by itself.+