Quorum-Based Commit Protocol
Let's probe how the quorum-based protocol solves the problem of the 3-phase commit protocol.
The problem with 3-phase commit protocol
As we observed in the previous lesson, the main issue with the 3PC protocol occurs at the end of the second phase, where a potential network partition can bring the system to an inconsistent state.
This can happen when participants attempt to unblock the protocol by taking the lead without having a picture of the overall system, resulting in a split-brain situation.
Coping with the problem
Ideally, we would like to cope with this network partition without compromising the safety of the protocol. This can be done using a concept we have already learned in this course: a quorum.
This approach is followed by the
This protocol is significantly more complex when compared to the other two protocols we described previously, so we should study the original paper carefully to examine all the possible edge cases. However, we will attempt to give a high-level overview of the protocol in this section.
As we mentioned before, this protocol leverages the concept of a quorum to ensure that different sides of a partition do not arrive at conflicting results.
The protocol establishes the concept of a commit quorum ...