© 1999 by British Computer Society
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Approximate Estimation of Transaction Response Time
A1 Department of Computing and Electrical Engineering, Heriot-Watt University, Edinburgh, EH14 4AS, Scotland, UK Email: howard@cee.hw.ac.uk
This paper describes a study of different approximation techniques used to predict the response times of database transactions represented as patterns of resource consumption and modelled with non-product-form queueing networks. The techniques are applied to a range of examples. The experiments show that none of the approximation techniques has a consistent advantage over the others for all cases considered. On the other hand, a simple heuristic rule is formulated which provides an acceptable approximation to the average transaction response time for the entire range of examples. The rule specifies a procedure for labelling each queue in a queueing network as either an M/M/1 or an M/G/1 resource. The resulting network can then be solved to obtain the mean response time of individual transactions.
Received 14 September, 1998. Revised 19 March, 1999.