edith@ai.toronto.edu (Edith Fraser) (02/23/90)
Department of Computer Science, University of Toronto (GB = Galbraith Building, 35 St. George Street) ------------------------------------------------------------- SYSTEMS GB244, at 2:00 p.m., 6 March 1990 Philip A. Bernstein Digital Equipment Corporation Edith Fraser Recoverable Queues Transactions have been rigorously defined and extensively studies in the database and transaction processing literature, but little has been said about the handling of requests for transaction execution. In commercial TP systems, managing the flow of requests is often as important as executing the transactions themselves. In practice, this is commonly done using persistent queues. This talk discusses uses of queues for moving requests reliably between clients and servers. In combination with transactions, queues can be used to ensure that a server processes each request exactly once and that a client processes each replay at least once. We describe the main features of queuing systems, we propose some new features, and we explain how each feature is used to support reliable processing of requests