We are having trouble controlling a long running process that uses WCF to send start/stop commands.
The problem seems to be that WCF does not respond to the requests when the CPU load is high. Unfortunately, high CPU on as many cores as possible is necessary for the application in question as it needs to perform a large number of numeric calculations.
Could the problem be related to the use of the thread pool to dispatch requests in WCF? This (somewhat dated) link suggests that it could:
"we don't spin up new threads when CPU usage is higher than 80%"