Can you give an example of two-phase commit?

Can you give me an example of how the two-phase commit protocol works?

Sure! The two-phase commit protocol is used in distributed systems to ensure all participants agree on a transaction. In the first phase, the coordinator asks all participants to prepare for the commit. Each participant responds with either 'ready' or 'not ready.' If all respond 'ready,' the coordinator moves to the second phase.

What happens in the second phase?

In the second phase, if all participants are ready, the coordinator sends a commit message to all. If any participant is not ready, it sends a rollback message. This ensures that all nodes either commit or rollback the transaction, maintaining consistency.

Can you give a real-world scenario where this is used?

Absolutely! A common example is in banking systems where a transfer between accounts must either complete fully or not at all. If one bank confirms the transfer but the other does not, the transaction must be rolled back to avoid inconsistencies.

What are the drawbacks of using two-phase commit?

Some drawbacks include potential blocking if a participant fails, increased latency due to the two phases, and complexity in handling failures.