Symptoms

We recently upgraded our test environment from k2 blackpearl 4.6.7 to 4.6.11 and are currently performing validation. It appears that since the upgrade the lsass.exe process is consuming about 1.9 GB and growing and consistently around 30% of CPU. We are only seeing this in the upgraded test environment. In the development and production environments running on 4.6.7 the lsass.exe process is only taking 30 MB of memory or less and pretty much no CPU. I tried to reboot and it clears the issue, but then over time the memory just keeps creeping up again.
 

Diagnoses

High memory utilization may come from a variety of sources including: closed firewall port on the domain controller, a custom service improperly closing connections and solutions downloaded from the market place not tested against the version of K2 installed.
 

Resolution

The K2 Process Error Notification Service was the issue. He changed the frequency of the run to only once an hour and the memory of the process still looks good after 4 days.