On one of my Dispatcher (slave) I had Warning message: "Request Processor Queue Full for Internal Admin Pool".
How is configured (wich parameter) size of the queue Internal Admin Pool? There is no the parameter in the documentation.
This queue cannot be resized.
" Queue Full for Internal Admin Pool" means that one instance (at least) seems to be overloaded.
In this case, checking the instances status by monitoring is the best approach.
I recommend you to open an incident in order to let the support investigate where is the origin of this behavior.