Replication
Observation: replication of service and data masks network problems.
- at least partially. Mainly depends on application semantics.
Questions:
- How many replicas do we need? (dynamic).
- Where do we place them? (dynamic).
- How do we direct the clients to the best server (often tricky).
- Which replication method to use? (primary backup, anti-entropy, active replication).
Cost and benefit online decision.