A two-phase commit protocol and its performance

A number of schemes have been used in distributed database systems to coordinate the execution of the subtransactions of a global transaction. We study the performance of a simple modification to the basic two phase commit protocol called Prudent Two Phase Commit protocol. The protocol gives the transaction a second chance before it decides to abort it. This prudent approach prevents a transaction from aborting in case of transient communication failures and hence improves system performance and reliability. To measure the performance of this protocol, we simulate a distributed database system. The performance of this simulated distributed system is measured while using the Prudent, Basic, and Optimistic Two Phase Commit protocols. The results of this simulation study are presented with a discussion and interpretation of the graphs generated by the simulation. The results confirm the improvement in system performance with the Prudent Two Phase Commit Protocol.