Where does ACME stand today?
Availability: failures are common
- Traditional fault-tolerance doesn’t solve the problems
Changability
- In back-end system tiers, software upgrades difficult, failure-prone, or ignored
- For application service over WWW, daily change
Maintainability
- system maintenance environments are unforgiving
- human operator error is single largest failure source
Evolutionary growth
- 1U-PC cluster front-ends scale, evolve well
- back-end scalability difficult, operator intensive