Definition - What does
A two-phase commit is a standardized protocol that ensures a commit is implementing when the commit operation must be broken into two separate parts. In database management, saving data changes is known as a commit and undoing changes is known as a rollback. Both can be achieved easily using transaction logging when a single server is involved, but when the data is spread across geographically-diverse servers in distributed computing (i.e., each server being an independent entity with separate log records), the process can become more tricky.
A special object, known as a coordinator, is required in a distributed transaction. As its name implies, the coordinator arranges activities and synchronization between distributed servers. The two-phase commit is implemented as follows:
Phase 1: Each server that needs to commit data writes its data records to the log. If a server is unsuccessful, it responds with an Oops message, which indicates failure. If successful, the server replies with an OK message. Phase 2:This phase begins after all participants respond OK. Then, the coordinator sends a signal to each server with commit instructions. After committing, each writes the commit as part of its log record for reference and sends the coordinator a message that its commit has been successfully implemented. If a server fails, the coordinator sends instructions to all servers to roll back the transaction. After the servers roll back, each sends feedback that this has been completed.
Object-Oriented Programming (OOP)
Related White Papers
Object Oriented Programming (OOP)
Recommended For You
Fast News Nation: Why Social Media Almost Works As a News Source
Connect with us
Techopedia on Linkedin
Follow us on LinkedIn
Techopedia on Twitter
Sign up for Techopedia's Free Newsletter!
History of Tech
Who To Follow
Buzzwords and Jargon
World Wide Web