Overview

Please read the paper and answer the question before coming to the lecture.

Lecture 2

Lec2: [RPC]

There are three potentially interesting RPC semantics:

What does the RPC package described in the paper provide? What are the tradeoffs when deciding which semantics an RPC package should provide?

Lecture 3

Flat Datacenter Storage Suppose tractserver T1 is temporarily unreachable due to a network problem, so the metadata server drops T1 from the TLT. Then the network problem goes away, but for a while the metadata server is not aware that T1's status has changed. During this time could T1 serve client requests to read and write tracts that it stores? If yes, give an example of how this could happen. If no, explain what mechanism(s) prevent this from happening.

Lecture 4

Is Paxos guranteed to terminate with a consensus if there are a majority of live nodes available? Why and why not?

Lecture 5


In the above timeline graph, X and Y are shared variables (or data objects) whose initial values are 0. tmp, tx, ty are per-client local variables. The grey bars mark the start and finish time of each Read/Write request.

Please explain all the possible values of tx and ty if the underlying system storing X and Y is linearizable.