Question: For each of the systems listed, sketch the logic of a process-oriented model and of an event-oriented model. For both approaches, develop and simulate the model in any language:
• a central-server queueing model: when a job leaves the CPU queue, it joins the UO queue with shortest length.
• a queueing model of a database system, that implements fork join: a job receives service in two parts. When it first enters the server it spends a small amount of simulation time generating a random number of requests to disks. It then suspends (freeing the server) until such time as all the requests it made have finished, and then enqueues for its second phase of service, where it spends a larger amount of simulation time, before finally exiting. Disks may serve requests from various jobs concurrently, but serve them using FCFS ordering. Your model should report on the statistics of a job in service-how long (on average) it waited for phase 1, how long it waits on average for its UO requests to complete, and how long it waits on average for service after its UO requests complete.