A datacenter may provide many different distributed-processing services within its network, services that may be run on different clusters, or groups, within the datacenter. Such services may entail the performance of different jobs. Different services, groups, jobs, datacenter clients, and/or customers may have differing performance requirements and/or may benefit from different levels of Quality of Service (QoS). To meet performance objectives and realize optimization opportunities in a networking environment, attention can be given to the traffic on datacenter networks and to the efficient use of network resources.
However, the nature of datacenters and/or the services that they provide present some unique challenges for traditional approaches for addressing these issues with network traffic and network resources. Some of these unique challenges are discussed below. In a datacenter environment, therefore, meeting different performance objectives, providing fine-grained levels of QoS, and/or leveraging optimization opportunities, require new innovations.