A model for the performance of locking algorithms in distributed database systems

A method to approximate the mean value of various performance parameters in distributed database systems using locking for concurrency control is proposed. The main contribution of this approach is its ability to model the interactions between resource and data contention and their effects on system performance. The system performance is evaluated at a point where the interaction between these two factors is in equilibrium. The model involves the solution of a set of simultaneous polynomial equations whose order is dependent on the input parameters, i.e., the size of the network. These equations are solved by an iterative procedure to yield approximate values of relative throughput, utilization of servers and the means as well as higher order moments of the transaction response time. The model has good convergence characteristics and the input parameters can be bounded to determine regions of existence, non-existence and possible existence of a solution. A simulator was used to validate the analytical model and the results agree quite well