Implementation and measurements of efficient communication facilities for distributed database systems

Experimentation with several methods of providing efficient communication facilities for distributed database systems is described. These studies give insight into the delays incurred by applications running on distributed systems. Five different mechanisms for local interprocess communications (two variations with message queues, named pipes, shared memory, and UDP sockets) have been implemented, compared, and analyzed. The most efficient of these is three times as fast as UDP for 1000-byte messages. Kernel-level software multicast and hardware multicast have also been implemented and their performance analyzed. The results show the significant advantage of using these techniques instead of using multiple sends and receives at the user level. The design of a facility that allows the dynamic addition of user-level protocols such as two-phase commit, clock synchronization, etc. to an operating system kernel is presented. The facility is based on a simple stack-based language that provides the functionality and security required