3-Phase Commit (3PC)
Explore the 3-phase commit protocol as a solution to the coordinator failure issue in 2PC. Understand how splitting the commit process allows participants to independently complete transactions, enhancing availability. Learn about the trade-offs with atomicity when facing network partitions, gaining insight into protocol design challenges for distributed atomicity.
The problem with 2-phase commit protocol
As we described previously, the main bottleneck of the 2-phase commit protocol was failures of the coordinator leading the system to a blocked state.
Ideally, we would like the participants to be able to take the lead in some way and continue the execution of the protocol in this case, but this is not so easy.
The underlying reason is the fact that in the commit phase, the participants are not aware of the state of the other participants—only the coordinator is So, taking the lead without waiting for the coordinator can result in breaking the atomicity property.
For instance, imagine the following scenario: in the commit phase of the protocol, the ...