Symptoms

we see that the K2 Hostserver process is hungry for memory. Normally it’s around 250 / 400 MB, as it still is in production (4.6.8), but now it’s easily a gigabyte or more.
 

Diagnoses

We found a document that mentioned the clearing of the PandD cache on the K2 server (the document was hard to find somehow) and tried page 29, point 10:
Document: https://help.k2.com/files/6786
 

Resolution

We deleted the HostServer and Temp folder inside the C:ProgramDataSourceCode folder (deleting the Temp folder wasn't described in the document.

After that, the memory use is still growing when using PandD. But after a while the memory use is going back to normal for us (around 300MB).