Modeling Host Load Peter A. Dinda Thesis Seminar 2/9/98

2 Outline Why model host load? Desirable properties Modeling techniques Results of Markov modeling

3 Why Model Host Load? Load partially determines exec time Benchmarks for trace-based simulation –Classification scheme for load traces Generalization of simulation results –Performance in terms of model parameters [t min,t max ]?

4 Desirable Properties Classification power –Few parameters –Significant properties of original traces Generation of load traces –Traces with similar significant properties Prediction of load –Mean square error sense

5 Modeling Techniques Markov models Stochastic processes –AR, MA, ARMA, ARIMA,...

6 Markov Modeling Simple model –Discretized load levels map to states O(n^2) transitions Vector model –State includes last d discretized levels Capture momentum, acceleration,... O(n^2d) transitions 39 load traces (1 Hz sample rate, 1 week)

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