[Announcements | Schedule and Readings | Assignments and Quizzes | Syllabus/Policies ]
Reading Questions, Lecture 15 (10/27)
Papers: Transaction Management in R*,
Dangers of Replication and A Solution
These papers talk about distributed transactions and replication -- though the second paper doesn't talk about ACID-style
transactions as we have discussed them it is related in that there are new consistency requirements that replication introduces.
As you read the papers, consider the following questions:
- In the "R*" paper, how does the two phase commit (2PC) protocol work? What problem does it solve? What are the costs of using it?
- What is the significance of the Presumed Abort/Presumed Commit variants of 2PC? How do they reduce the overhead of 2PC? When should you choose one over the other?
- In the "Dangers of Replication" paper, what are the tradeoffs between lazy/eager and group/master replication in terms of read performance, write performance, and availability?
- What is the "danger of replication" to which this paper refers?
- What is the "solution"? Do you buy that this is a reasonable way to solve this problem?
Samuel Madden (madden at csail dot mit dot edu)
Last modified: Sat Nov 6 18:08:47 EST 2004