Is there a free lunch for cloud-based evolutionary algorithms?

In this paper we present a distributed evolutionary algorithm that uses exclusively cloud services. This presents certain advantages, such as avoiding the acquisition of expensive resources, but at the same time presents the problem of choice between different services at different levels (infrastructure, platform, software) and, finally the actual scalability that can be achieved in a real distributed evolutionary algorithm. These issues are addressed by creating a pure-cloud version of EvoSpace, a pool-based evolutionary algorithm previously presented by the authors. EvoSpace is tested using the free tier of two services (one for the pool and other for the clients) and also the paying tier, and speedup is measured and its limits assessed. In general, this paper proves that a low-cost distributed evolutionary algorithm system can be created using cloud services that can be set up in very short time, but that major efficiency improvements can be obtained by switching to the non-free tier, giving another twist to the famous phrase “there is no free lunch”. We also show that using a pool-based algorithm allows to use cloud services more efficiently (and dynamically) than a static or synchronous service.