System Failure Modes Failures unique to distributed systems: ·Failure of a site. ·Loss of massages Handled by network transmission control protocols such as TCP-IP Failure of a communication link Handled by network protocols,by routing messages via alternative links Network partition A network is said to be partitioned when it has been split into two or more subsystems that lack any connection between them Note:a subsystem may consist of a single node Network partitioning and site failures are generally indistinguishable. Database System Concepts-7th Edition 23.5 ©Silberscha乜，Korth and SudarshanDatabase System Concepts - 7 23.5 ©Silberschatz, Korth and Sudarshan th Edition System Failure Modes ▪ Failures unique to distributed systems: • Failure of a site. • Loss of massages ▪ Handled by network transmission control protocols such as TCP-IP • Failure of a communication link ▪ Handled by network protocols, by routing messages via alternative links • Network partition ▪ A network is said to be partitioned when it has been split into two or more subsystems that lack any connection between them • Note: a subsystem may consist of a single node ▪ Network partitioning and site failures are generally indistinguishable