1. Define and distinguish among the following terms on scalability: 

a. Scalability over machine size 

b. Scalability over problem size 

c. Resource scalability 

d. Generation scalability 

2. Explain the architectural and functional differences among three availability cluster configurations: hot standby, active takeover, and fault-tolerant clusters. Give two example commercial cluster systems in each availability cluster configuration. Comment on their relative strengths and weaknesses in commercial applications.