DCSim: A Data Centre Simulator

Developing algorithms to dynamically manage resources in a virtualized, multi-tenant data centre is challenging. Experimenting with such algorithms on the data centre scale is impractical due to size and complexity. Thus, there is a need for simulation tools to allow rapid development and evaluation of management techniques. We present DCSim [1], an extensible framework for simulating a multitenant, virtualized data centre. Performance & Scalability Experiments were performed with varying number of VMs and Hosts, and simulation running time was recorded. Future Simulator Improvements Racks & Clusters: Hosts within the simulated data centre should be organized into racks and clusters. Management decisions could then be made based on this information. Networking: Network bandwidth and utilization should be modelled within the simulation. This is especially important as it pertains to VM live migration time, bandwidth usage, and effect on other running VMs. Thermal & Cooling Costs: The heat produced by hosts could be modelled, and cooling costs calculated. Heat could then be taken into consideration by management policies. Memory Overcommitting: Some virtualization technologies allow memory to be overcommitted, which potentially allows for more VMs to be co-located on a single host. Architecture In DCSim, a data centre consists of a set of interconnected Hosts (physical machines), governed by a set of Management Policies. Each host has a set of Resource Managers that handle local resource allocation, a CPU Scheduler which decides how VMs will execute, and a Power Model which models how much power is being consumed by the host at any point in time. Each host runs a set of VMs, which in turn each run a single Application.