Optimal power allocation among multiple heterogeneous servers in a data center

In a data center for cloud computing, there are typically multiple heterogeneous servers which provide services in different application domains. For such heterogeneous servers in a data center with different configurations for diversified applications and certain available power, there is a problem of allocating the power to the servers, such that the overall quality of service of the servers in the data center is optimized. We address power constrained performance optimization in a data center with multiple heterogeneous servers. We consider the problem of optimal power allocation among multiple heterogeneous servers, i.e., minimizing the average task response time of multiple heterogeneous computer systems with energy constraint. Each server is treated as a queueing system and the average task response time in a data center with multiple servers is formulated as a function of power allocations to the servers. The average task response time is minimized subjected to the constraint that the total effective power consumption of all the servers does not exceed a given power limit. We develop an algorithm to find the optimal solution and demonstrate numerical data. We also develop several closed-form heuristic solutions and show that they are very close to the optimal solution. Our approach provides an analytical way of studying the power-performance tradeoff at the data center level.