Evolution of a Communication System for Distributed Transaction Processing in Raid

This paper identifies the basic services required from a communication subsystem to support transaction processing in a distributed, reliable, reconfigurable, and replicated database environment. These services include multicasting, remote procedure calls (RPC), inexpensive datagram services, and efficient local interprocess communication (IPC). We show the evolution of the various versions of Raid communication software and our experience with them. rile show how several ideas such as lightweight protocols, simple naming, memory mapping and shared memory, physical multicasting, direct control passing, and adaptability fulfill the needs for transaction processing. rüe present performance data on these ideas and study their impact on transaction processing. We also use the results of these studies to design and implement a new communication scheme. This scheme has reduced the overhead of communication in Raid distributed database system by up to 70. This research is supported by NASA and AIRMICS under grant number NAG-l-676, NSF grant IRI-8821398, and AT&L @ Computing Systems, Vol. 4 ' No. 3 ' Summer 1991 277