3. Servers

Question 1

List advantages of computing as a utility using cloud services.

Answer 1

Allows for pay as you go style:

• on demand
• use only what you need
• can get virtual machines to a specification

Question 2

List differences between client and server systems.

Answer 2

servers:

• can use virtualisation
• resilient, can hot swap
• 24/7 uptime
• high amount of concurrent connections
• high bandwidth
• high power consumption
• needs to be able to anticipate and deal with exceptions

Question 3

What is a daemon process?

Answer 3

An unattended process, a background process. Servers will usually run as a daemon process.

Question 4

How do TCP servers deal with multiple incoming requests?

Answer 4

Requests are queued, FIFO. The backlog is the maximum length of the queue. If a connection arrives when the queue is full, the connection is refused.

Question 5

What information do servers log about connections and transactions?

Answer 5

• client name/address
• date/time connection made
• date/time connection closed
• protocol specific info e.g http records name of file retrieved and error codes