Method and apparatus for automatic performance modeling with load dependent service times and overheads

A method for automated performance modeling of an information technology system, the method comprising:

• monitoring transactions exchanged between a plurality of servers of an information technology system to measure an average arrival rate of each transaction type at each server;
• modeling a service time of each transaction type at each server as one of a polynomial, exponential, or logarithmic function of an average arrival rate of each transaction type at the corresponding server to generate a service time function;
• modeling a processor overhead at each server as one of a polynomial, exponential, or logarithmic function of the average arrival rate of each transaction type at the corresponding server to generate a processor overhead function;
• inferring optimal values of coefficients in the service time and processor overhead functions by minimizing a quadratic objective function;
• determining the service time and processor overhead functions using the inferred optimal values of the coefficients;
• and
• generating a performance model of the information technology system from the determined service time and processor overhead functions.

A program storage device readable by machine, tangibly embodying a program of instructions executable by the machine to perform method steps for modeling performance of an information technology system including a plurality of servers, the method steps comprising:

• monitoring transactions exchanged between a plurality of servers of an information technology system to measure an average arrival rate of each transaction type at each server;
• modeling a service time of each transaction type at each server as one of a polynomial, exponential, or logarithmic function of an average arrival rate of each transaction type at the corresponding server to generate a service time function;
• modeling a processor overhead at each server as one of a polynomial, exponential, or logarithmic function of the average arrival rate of each transaction type at the corresponding server to generate a processor overhead function;
• inferring optimal values of coefficients in the service time and processor overhead functions by minimizing a quadratic objective function;
• determining the service time and processor overhead functions using the inferred optimal values of the coefficients;
• and
• generating a performance model of the information technology system from the determined service time and processor overhead functions.

A system for modeling performance of an information technology system having one or more servers for serving a number of types or classes of transactions, the system comprising:

• a monitoring module to monitor the transactions exchanged between the servers to measure an average arrival rate of each transaction type at each server;
• a modeling module to model a service time of each transaction type at each server and a processor overhead at each server as one of a polynomial, exponential, or logarithmic function of the average arrival rate of each transaction type at the corresponding server to generate service time and processor overhead functions;
• and
• an enhanced inferencing module to infer optimal values of coefficients in the service time and processor overhead functions to generate a performance model of the information technology system.