Under What Constraints to Scale?
Two types of constraints:
- User-oriented, e.g. particles, rows, transactions, I/Os per processor
- Resource-oriented, e.g. memory, time
Which is more appropriate depends on application domain
- User-oriented easier for user to think about and change
- Resource-oriented more general, and often more real
Resource-oriented scaling models:
- Problem constrained (PC)
- Memory constrained (MC)
- Time constrained (TC)
(TPC: transactions, users, terminals scale with “computing power”)
Growth under MC and TC may be hard to predict