Lecture 7
The topic of this lesson is replication. We often replicate data and services for various reasons: improved performance, higher availability, and improved fault-tolerance. Replication is often the key to achieving those properties. Replication sounds deceptively simple, but as we will see during the lecture, ensuring that all replicas (copies) are up-to-date in a consistent way is hardly trivial. For some applications, strictly consistent replicas are not required -- the high availability property is more important. We shall introduce one such system called Gossip.
The outline for the lecture is as follows:
- Introduction
- System model
- Group communication
- Fault-tolerant services
- Passive primary backup
- Active primary backup
- Highly available services
- Introduction to Gossip
No lecture notes this time!
Reading
Intensive reading: 15.1 - 15.4.1
Extensive reading: 15.4.2 - 15.4.3
Exercises
Primary set: 15.1, 15.2, 15.5, 15.7 - 15.10, 15.12 - 15.14
Secondary set: 15.3, 15.4, 15.6, 15.11