When do we measure time?
There are many activities that need accurate measurement of time in studying distributed systems:
- analysis of system performance
- e.g. cache or factory performance
- analysis of network performance
- E.g study of protocol design or network technology
We are often interested in delay between systems, but we generally need a start and end time to calculate delay;
If measurements are to be taken over long periods, an accurate clock is needed to give good delay information.