A system is composed of CPU, Disk and Network. The execution of a process proceeds as follows: 1. The process uses the CPU and then with probability 0.2 proceeds to step 2, with probability 0.3 proceeds to step 3, and with probability 0.5 proceeds to step 4 2. The process performs Disk I/O and then with probability 0.3 proceeds to step 1, and with probability 0.7 proceeds to step 4 3. The process performs Network I/O and then with probability 0.4 proceeds to Step 1 and with proba bility 0.6 proceeds to step 4. 4. The process is leaves the system (perhaps due to an I/O error) The following information is known about this system: Processes arrive according to a Poisson process with an average rate of 40 processes per second The service time of the CPU is exponentially distributed with an average of 15 msec. The service time of the Disk is exponentially distributed with an average of 50 msec The service time of the Network is exponentially distributed with an average of 60 msec. All buffers are of infinite sizes Answer the following questions [3 points each: (a) Draw a queuing diagram depicting the system above. (b) Which resource is the bottleneck resource? (c) What is the average total turnaround time for a process submitted to the above system? (d) What is the probability that a process would not experience any waiting time once it gets submitted to the CPU? (e) What arrival rate would render this system unstable! A system is composed of CPU, Disk and Network. The execution of a process proceeds as follows: 1. The process uses the CPU and then with probability 0.2 proceeds to step 2, with probability 0.3 proceeds to step 3, and with probability 0.5 proceeds to step 4 2. The process performs Disk I/O and then with probability 0.3 proceeds to step 1, and with probability 0.7 proceeds to step 4 3. The process performs Network I/O and then with probability 0.4 proceeds to Step 1 and with proba bility 0.6 proceeds to step 4. 4. The process is leaves the system (perhaps due to an I/O error) The following information is known about this system: Processes arrive according to a Poisson process with an average rate of 40 processes per second The service time of the CPU is exponentially distributed with an average of 15 msec. The service time of the Disk is exponentially distributed with an average of 50 msec The service time of the Network is exponentially distributed with an average of 60 msec. All buffers are of infinite sizes Answer the following questions [3 points each: (a) Draw a queuing diagram depicting the system above. (b) Which resource is the bottleneck resource? (c) What is the average total turnaround time for a process submitted to the above system? (d) What is the probability that a process would not experience any waiting time once it gets submitted to the CPU? (e) What arrival rate would render this system unstable
