When a webserver is full of clients, some clients may have bad plugins or code, memory leaks etc. This could cause resources to go up to maximum and a client wil get temp limited. The is currently no way to fight this except restart PHP manually.
I would like to see LVR stepping in and kill this process of it runs longer then xx hours. This way the resource limit will not get hit and clients will not be limited. Sites will stay online.
A notice should be send, what process is killed and why. So we as server engineers know what happened.