One of the benefits of an open source virtualization/cloud stack is the opportunity to customize the commodity components to deliver differentiated services. This article examines the opportunity to dramatically reduce the cost of delivering cloud services using the open source, open standard instrumentation available as part of the Xen Cloud Platform.
The following diagram shown the architectural components of the Xen Cloud Platform and shows how sFlow instrumentation fits within the XCP architecture.
The Control Interface (XE/XAPI) configures and controls resources within the Resource pool (e.g. provisioning, starting, stopping and migrating virtual machine and storage resources). Enabling sFlow in XCP (provided by Open vSwitch and Host sFlow) adds highly scalable performance monitoring and usage metering of the cloud infrastructure; including visibility into physical and virtual network, server and storage activity.
Real-time monitoring allows resources to be optimally provisioned to match demand. Adjusting capacity to demand reduces costs by eliminating over provisioning and applying resources where they are needed to avoid service failures.
In addition, detailed usage data allows for differentiated billing strategies (for example charging different rates for local and non-local network traffic). Aligning billing policies with the cost of delivering services allows services to be delivered at a variety of price points and encourages customers to use resources efficiently.
The steps needed to enable sFlow monitoring in Xen Cloud Platform are described in the article, XCP 1.0 beta. Most switch vendors also support the sFlow standard (instructions for enabling sFlow on most vendor's switches are documented in articles on this blog). The combination of sFlow from switches and XCP provides the data center wide, end-to-end visibility needed for complete control.
For additional information, the sFlow presentation provides a strategic view of the role that sFlow monitoring plays in managing converged, virtualized and cloud environments.