Availability is the most important consideration for designing servers, followed closely by scalability and throughput.

a$.[10]<mn\; id="EditorElement\_2194618">1</mn><mn\; id="EditorElement\_2194619">.</mn><mn\; id="EditorElement\_2194620">7</mn>$: We have a single processor with a failure in time $($FIT$)$ of $100.$ What is the mean time to failure $($MTTF$)$ for this system?

b$.[10]<mn\; id="EditorElement\_2194462">1</mn><mn\; id="EditorElement\_2194463">.</mn><mn\; id="EditorElement\_2194464">7</mn>$: If it takes one day to get the system running again, what is the availability of the system?

c Imagine that the government, to cut costs, is going to build a supercomputer out of inexpensive computers rather than expensive, reliable computers. What is the MTTF for a system with $1000$ processors? Assume that if one fails, they all fail.