Ref:
- https://martinfowler.com/articles/patterns-of-distributed-systems/two-phase-commit.html
- https://en.wikipedia.org/wiki/Two-phase_commit_protocol
Usage
When data needs to be atomically stored on multiple nodes.
Steps
- Prepare phase asks if other node is ready to commit and promises to commit
- Commit phase where both nodes store the data.
If any node is ready, the transaction is aborted.
Visual
Disadvantage
It’s a blocking protocol which means it’s slow. Needs to wait for all participants to respond with prepared to commit.