Optimal Resource Allocation to Host Web Services in Cloud

In this paper, we analyze the performance of computation intensive and memory demanding web services hosted in different environments with the same amount of resources, but orchestrated differently. A single-VM addresses the environment where all the resources are allocated in one huge virtual machine instance (VMI), while a multi-VM environment uses several smaller VMIs, each allocated with only one CPU core, and the load is balanced among them. We realize series of experiments with different server loads by changing the message size and the number of concurrent messages to analyze the optimal resource allocation to host web services in order to achieve maximum performance from the same resources in the cloud, i.e., for the same price. Despite the hypothesis that the single-VM environment provides better performance than the multi-VM environment, the results show totally opposite for almost all test cases. We achieve maximal relative speedup of 9.83 comparing the multi-VM environment to the single-VM.