|Figure 1: Best of Velocity 2012, The sFlow Standard|
Figure 1 shows the strategic role that ADCs (load balancers) play in controlling the flow of application requests, regulating admission, filtering, directing loads, and virtualizing services. RESTful control of ADCs combined with real-time visibility provides a powerful capability for flexing resources as demand changes, reducing costs and increasing performance as resources are closely matched to workloads.
What is unusual about diagram is the inclusion of the network. Application architects often give little thought to the network since its complexity is conveniently hidden behind APIs. Unfortunately, it is in the nature of scale-out applications that their performance is tightly coupled to that of the network. In addition, the network is shared between application tiers, allowing performance problems to propagate.
|Figure 2: sFlow drivers for growth|
|Figure 3: Visibility and the software defined data center|
Performance Aware SDN describes the theory behind analytics driven orchestration. The talk describes how fast controller response, programmatic configuration interfaces such as OpenFlow, and consistent instrumentation of all the elements being orchestrated are pre-requisites for feedback control.The requirement for complete measurement coverage by next generation orchestration systems will create a strong demand for sFlow instrumented infrastructure since sFlow is the only widely supported multi-vendor standard that spans network, server and application resources and delivers the low latency and scaleability required for adaptive control.