Towards Systematic Data Center Design

Data centers are changing fast. The rapid increase of reliance on cloud computing, particularly in the context of “big data” applications, inevitably leads to the following fact: data centers must constantly update and adapt to the increased user requirements. This fact becomes more evident if we consider today’s cloud environments. The users of these environments have very strict requirements: they expect to have access to specific hardware resources (IOPs, memory capacity, number of CPU cores, network bandwidth), they demand data availability and durability guarantees, defined quantitatively in Service-Level Agreements (SLAs) [1, 2], and they will soon expect to get concrete performance guarantees defined in performance-based SLAs (e.g. [4,5]). Given these user expectations, the natural question to ask is the following: “How should we design the data centers of the future?” Data center design is a tedious and expensive process. Typically, data center designers determine the hardware setup based on the software that will be deployed, and the expected workload characteristics. For example, in an environment where high availability is important, the data is replicated (e.g., three or five times), and storage is provisioned to accommodate the number of copies. This process leads to an iterative approach to data center design: the software configuration is determined first and then the hardware setup (or vice versa). However, such approaches may not always be optimal since they ignore important interactions between these two components [3]. What we propose is an integrated approach that explores the hardware/software interdependencies during the data center design process. We believe that the most cost-effective, extensible and efficient way of performing integrated data center design is to use a “wind tunnel” to simulate the entire space of hardware/software co-design. The “wind tunnel” can be used to explore, experiment, and compare design choices, and to reason about the statistical guarantees that these design choices can provide. There are a lot of interesting research challenges involved in the process of designing, building and using the simulation-based “wind tunnel”. Designing lan-