Two Phase Commit Protocol(2PC) Assumes fail-stop model-failed sites simply stop working,and do not cause any other harm,such as sending incorrect messages to other sites. Execution of the protocol is initiated by the coordinator after the last step of the transaction has been reached. The protocol involves all the local sites at which the transaction executed Let T be a transaction initiated at site Si,and let the transaction coordinator at Si be Ci Database System Concepts-6th Edition 19.21 @Silberschatz,Korth and SudarshanDatabase System Concepts - 6 19.21 ©Silberschatz, Korth and Sudarshan th Edition Two Phase Commit Protocol (2PC) Assumes fail-stop model – failed sites simply stop working, and do not cause any other harm, such as sending incorrect messages to other sites. Execution of the protocol is initiated by the coordinator after the last step of the transaction has been reached. The protocol involves all the local sites at which the transaction executed Let T be a transaction initiated at site Si , and let the transaction coordinator at Si be Ci