We run FME Server with 2 Engines on the same VM as ArcGIS Server. Lately we experimented with new functionalities in FME Server workspaces that caused very high CPU usage that first crashed the FME Server Core Service then also the ArcGIS Server Service.
Geoserver offers an option to limit the max number of threads when seeding tiles...is there a similar option for FME Server to set this per Engine? The alternative would be quite costly for us (have a dedicated VM just for FME Server).
Usually FME Server runs 1 thread per engine, the challenge is always to try and use more CPU to make the most out of it ha! One of FME's limitations is that it isn't really multi threaded. You really need to design a workflow to take advantage of multiple cores if you have them.
What was the process where you saw more than this? and are you sure that high CPU was the cause of the issue here?
As a general rule it's typically recommended to have one cpu/core per engine.
If you are using the parallel processing option within FME you have the option to chose the number of child processes to be relative to the number of cores available. Minimal, processes = 1/2 number of logical cores, Moderate: 1 per core Aggressive=1 1/2 per core and extreme = 2 per core.