Physical hosting

For many years, application architectures and design choices only had to consider the physical, barebones host for running various components of the architecture.  As web applications scaled and incorporated specialized platforms, additional hosts were added to meet the need. New database servers were added as the data sets became more diverse, additional application servers would be needed to incorporate additional software platforms, and so on. Labor and hardware resources are dedicated to each additional instance, but they add cost, complexity, and waste to a data center. The workloads depended on dedicated resources, and this made them both vulnerable and inflexible.