AIX IC agent metrics differ from topas
IC reports a 5 minute average for CPU usage and topas reports a (mostly) instantaneous value.
IC Requires a Process To Exist for at Least Two Collection Cycles
Since IC is designed for longer term monitoring, it requires that a process exist for at least two collection cycles before metrics specific to that process can be reported. This means that it is possible for IC to report 100% overall CPU usage, but not report any process over 1% if a process just starting using large amounts of CPU time. If the process still exists in the next collection cycle, its process CPU usage will be updated to reflect the how much it used over that entire collection cycle.
This particular behavior is by design. IC is not intended to provide instantaneous reporting and tries to avoid reporting spikes in usage that are transient. It is only when a process is using a large amount of resources for more than one monitoring cycle that it becomes interesting to us.
If there is a concern about values on the process usage dashboard, make sure that the exact same process is running for more than 5 minutes.
100% is a Very Tricky Concept on AIX
Foglight reports CPU usage as a percentage on AIX, and we define that maximum amount of CPU usage for a process as 100%.
However, the definition of 100% varies wildly on AIX and is very much open to interpretation. The simple definition of CPU usage is not applicable for AIX LPARs and WPARs as it is possible for an uncapped LPAR to use CPU cycles from a underused LPAR when it is very busy, leading to perfectly reasonable result of a process using more than 100% of the CPU time allocated to the LPAR.