Does the performance scale the same as the cost in the cloud

Cloud computing is a paradigm that offers on-demand scalable resources with the “pay-per-usage” model. Cloud service providers´ price rises linearly as the resources scale. However, the main challenge for the cloud customers is “Does the performance scale as the price for the rented resources in the cloud”? Also, how does the performance scales for different server load? In this paper we analyze the performance and the cost of a web service that utilize both memory and CPU varying the server load with different message size and number of concurrent messages in order to determine the real cost of rented CPU resources. The results show that the web service´s cost rises linearly with the resources, i.e. the lowest cost is determined while hosted on one CPU.