Transparent Concurrent Execution of Mutually Exclusive Alternatives

We examine the task of concurrently computing alternative solutions to a problem. We restrict our interest to the case where only one of the solutions is needed; in this case we need some rule for selecting between the solutions. We use ‘‘fastest first’’, where the first successful alternative is selected. For problems where the required execution time is unpredictable, such as database queries, this method can show substantial execution time performance increases. These increases are dependent on the mean execution time of the alternatives, the fastest execution time, and the overhead involved in concurrent computation. Among the problems with exploring multiple alternatives in parallel are side-effects and combinatorial explosion in the amount of state which must be preserved. These are solved by process management and an application of ‘‘copy-on-write’’ virtual memory management. The side effects resulting from interprocess communication are handled by a specialized...

• Type: Conference
• Year: 1989
• Where: ICDCS
• Authors: Jonathan M. Smith, Gerald Q. Maguire Jr.
• Keywords: Distributed And Parallel Computing, Execution Time, Execution Time Performance, ICDCS 1989, Required Execution Time