Persistent Messaging Implementation Atomic Transaction at Sending Node Atomic Transaction at Receiving Node Perform database updates Process any unprocessed message in .Write message to messages_to_send relation received_messages Mark message as processed messages to send received messages Message Delivery Process Message Receiving Process Monitor messages_to_send relation On receiving message,execute transaction to Send any new messages to recipient add message to received_messages relation, Also periodically resend old messages if not already present When Acknowledgment received from recipient, After transaction commits,send for a message,delete message Acknowledgement Database System Concepts-7th Edition 23.20 @Silberschatz,Korth and SudarshanDatabase System Concepts - 7 23.20 ©Silberschatz, Korth and Sudarshan th Edition Persistent Messaging Implementation