Abstract: In recent years, cloud computing has emerged as a cost-effective way to deliver on-demand and metered computing resources. In a cloud, elasticity of resource usage is typically realized through the “on-demand” provision principle supported by the “pay-as-you-go” business model. However, little has been investigated into elasticity of algorithm for cloud computing. This paper introduces a novel elastic algorithm (EA) in which the computation itself is organized in a “pay-as-you-go” fashion. In contrast to conventional algorithms, where computation is a deterministic process that only produces an “all-or-nothing” result, an EA generates a set of approximate results corresponding to its resource consumption. As more resources are consumed, better results can be derived. In this sense, quality of the algorithm is elastic to its resource consumption. The desirable properties for EA are formalized, and ambitious agenda for future research is provided in this area and propose several challenges.

Key words: cloud computing, elastic algorithm (EA), pay-as-you-go