Thanks to everyone who joined us for the March 14 DemoFriday featuring Plexxi and Real Status! The demo of application abstractions showed the power of combining a programmable network, an open source controller platform, and scalable visibility.
After the presentation, Plexxi’s Nils Swart (strategy and business development), Derick Winkworth (product management), and Real Status’ Stace Hipperson (CTO) took questions from participants. Read that Q&A below, check out the teaser video, or watch the full presentation and other resources here.
Does affinity fully support OpenFlow Switches?
Plexxi and Real Status: Affinities as abstract relationships descriptions are consumed by the OpenDaylight Controller and transformed into OpenFlow flows and actions. As such, the relationship defined in an affinity is devoid of network-specific implementation details, so a controller is needed to translate the described intent (a relationship between X and Y) to action (forward traffic from X coming in port 1 to Y going out port 3). If a network element forwards based on OpenFlow rules, then the controller would translate to OpenFlow rules. If a network system like Plexxi’s is involved, the affinity is processed to render/calculate a set of network paths.
Do affinity policies mean flow tables also?
Plexxi and Real Status: There is no direct correlation between an affinity policy and how it is rendered in the underlying infrastructure. It is possible that certain types of affinities of attributes are best rendered with tables. However, many affinities will not require flow tables to be implemented.
Are affinities the same as VLANs? Or do they replace VLANs? Is the idea of affinities to mimic natural language?
Plexxi and Real Status: No — however, due to the intuitive nature of affinity policy constructs, a network engineer could easily express a VLAN using them. Affinities represent a relationship in the infrastructure: “These things are talking to these other things.” What is a VLAN except a relationship amongst ports or MAC addresses? By placing ports and MAC addresses into groups and then creating an affinity link with both ends pointing to that group, you could then apply a VLAN attribute to that link. In effect, we are saying “These things are in a VLAN.”
In the future, we will see more types of affinities which allow network engineers to express relationships in the network in a more natural way.
Do I need vendor-specific controller when I have OpenDaylight?
Plexxi and Real Status: No and yes. OpenDaylight does not require you to throw away your existing controllers, or your existing network gear for that matter. OpenDaylight delivers a framework controller to build network-wide services and interfaces with many systems above and below. In this demo we have shown how OpenDaylight can federate (that is, communicate and cooperate with) the Plexxi controller to get to the end goal of delivering a network service.
The beauty of having a platform like OpenDaylight is that it’s a natural place where information/state from the infrastructure comes together. Hyperglance makes full use of the data available, which is multivendor in the demo. That’s powerful not just for visualization but also for taking actions across those multivendor infrastructures. (e.g., adding taps or isolated behaviors to a path or affinity).
Throughout the presentation you were talking about keeping data “fresh.” What do you mean by that?
Plexxi and Real Status: The purpose of a given DSE data module is to ensure that automations written on top of the DSE are kept current on the data they are interested in. In the demo, a DSE module was configured to monitor the affinity configuration within OpenDaylight. As changes occurred within OpenDaylight, the DSE published this information on its internal message bus.
How would, what you showed in the demo, scale to an average-size data center with, say, 1,000 server hosts?
Plexxi and Real Status: Every piece in the product set was designed for scale. Hyperglance is designed to handle many thousands of switches, routers, and hosts. OpenDaylight, while only at its first release, is built for extensibility, and the architecture should scale to the largest data centers. Plexxi’s SDN-based Layer 1, 2, and 3 Ethernet switch is the industry’s only truly single-tier, scale-out networking solution that allows you to scale linearly to meet capacity demands. With the introduction of an affinity abstraction, you get the benefit of describing the intended relationship without having to tailor the relationship based on infrastructure size.
Plexxi and Real Status: Yes, multiple vendors have both announced and delivered functionality to work with OpenDaylight. Pretty much any vendor can choose to either use its own APIs to build a southbound interface for OpenDaylight or use one of the available ones (OpenFlow, OVSDB). Affinities themselves do not assume a particular southbound interface. And after other vendors publish flow/path/topology information in Opendaylight, Hyperglance immediately gains access to it and can visualize the relationships.