Welcome!

Industrial IoT Authors: Jim Hansen, AppNeta Blog, Liz McMillan, Elizabeth White, XebiaLabs Blog

Related Topics: SDN Journal, Java IoT, Microsoft Cloud, Containers Expo Blog, @CloudExpo, @BigDataExpo

SDN Journal: Blog Feed Post

Scaling Stateful Network Devices

One of the premises of SDN and cloud scalability is that it's easy to simply replicate services

One of the premises of SDN and cloud scalability is that it's easy to simply replicate services - whether they be application or network focused - and distribute traffic across them to scale infinitely.

In theory, this is absolutely the case. In theory, one can continue to add capacity to any layer of the data center and simply distribute requests across the layer to scale out as necessary.

Where reality puts a big old roadblock in the way is when services are stateful. This is the case with many applications - much to the chagrin of cloud and REST purists, by the way - and it is also true with a significant number of network devices. Unfortunately, it is often these devices that proponents of network virtualization target without offering a clear path to addressing the challenges inherent in scaling stateful network devices.

SDN's claims to supporting load balancing, at least at layer 4, are almost certainly based on traditional, dumb layer 4 load balancing. We use the term "dumb" to simply mean that it doesn't care about the payload or the application or anything else other than its destination port and service and does not participate in the flow. In most layer 4 load balancing scenarios for which this is the case, the only time the load balancer examines the traffic is when processing a new connection. The load balancer may buffer enough packets to determine some basic networking details - source and destination IP and TCP ports - and then it establishes a connection between the client and the server. From this point on, generally speaking, the load balancer assumes the role of a simple forwarder. Subsequent packets with the same pattern are simply forwarded on to the destination.

If you think about it, this is so close to the behavior described by an SDN-enabled network as to be virtually the same. In an SDN-enabled network, a new flow (session if you will, in the load balancing vernacular) would be directed to the SDN controller for processing. The SDN controller would determine its destination and inform the appropriate network components of that decision. Subsequent packets with the same pattern would be forwarded on to the destination according to the information in the FIB (Forwarding Information Base). As the load balancing service was scaled out, inevitably packets would be distributed to components lacking an entry in the FIB. Said components would query the controller, which would simply return the appropriate entry to the device.

In such a way, simple layer 4 load balancing can be achieved via SDN*.

However, the behavior of the layer 4 load balancing service described is stateless. It does not actively manage the flow. Aside from the initial inspection and routing decision, the load balancing service is actually just a bump in the wire, forwarding packets much in the same manner as any other switch in the network.

But what happens when the load balancing service is actively participating in the flow, i.e. it is stateful.

Scaling Stateful Devices

Stateful devices are those that actively manage a flow. That is, they may inspect, manipulate, or otherwise interact with flows in real-time. These devices are often used for security - both ingress and egress - as well as acceleration and optimization of application exchanges. They are also use for content transformation purposes, such as XML or SOA gateways, API management, and other application-focused scenarios. The most common use of stateful devices is persistent load balancing, aka sticky sessions, aka server affinity. Persistent load balancing requires the load balancing service (or device) maintain a mapping of user to application instance (or server, in traditional, non-virtualized environments). This mapping is unique to the device, and without it a wide variety of applications break when scaled - VDI being the most recent example of an application relying on persistence of sessions .

In all these cases, however, one thing is true: the device providing the service is an active participant. The device maintains service-specific information regarding a variety of variables including the user, the device, the traffic, the application, the data. The entire context of the session is often maintained by one or more devices along the traffic chain.

What that means is that, like stateful, shared-nothing applications, it matters to which device a specific request is directed. While certainly the same model used at layer 4 and below in which a central controller (or really bank of controllers) maintains this information and doles it on on-demand, the result is that depending on the distribution algorithm used, every stateful device would end up with the same flows installed. In the interim, the network is frantically applying optimization and acceleration policies to traffic that may be offset by the latency introduced by the need to query the controller for session state information, resulting in a net loss of performance experienced by the end-user.

And we're not even considering the impact of secured traffic on such a model, where any device needing to make decisions on such traffic must have access to the certificates and keys used to encrypt the traffic in order to decrypt, examine, and usually re-encrypt the traffic. Stateful network devices - application delivery controllers, intrusion prevention and detection systems, secure gateways, etc... - are often required to manage secured content, which means distributing and managing certificates and keys across what may be an ever-expanding set of network devices.

The reality is that stateful network devices are a necessary and integral component of not just networks but applications today. While modern network architectures like SDN bring much needed improvements to provisioning and management of large scale networks, their scaling models are based on the premise of stateless, relatively simple devices not actively participating in flows. For those devices that rely upon deep participation in the flow, this model introduces a variety of challenges that may not find a solution that fits well with SDN without compromising on performance outside new protocols capable of carrying that state persistently throughout the lifetime of a session.

* This does not address the issue of resources required to maintain said forwarding tables in a given device, which given current capacity of commoditized switches supported for such a role seems unlikely to be realistically achieved.

Read the original blog entry...

More Stories By Lori MacVittie

Lori MacVittie is responsible for education and evangelism of application services available across F5’s entire product suite. Her role includes authorship of technical materials and participation in a number of community-based forums and industry standards organizations, among other efforts. MacVittie has extensive programming experience as an application architect, as well as network and systems development and administration expertise. Prior to joining F5, MacVittie was an award-winning Senior Technology Editor at Network Computing Magazine, where she conducted product research and evaluation focused on integration with application and network architectures, and authored articles on a variety of topics aimed at IT professionals. Her most recent area of focus included SOA-related products and architectures. She holds a B.S. in Information and Computing Science from the University of Wisconsin at Green Bay, and an M.S. in Computer Science from Nova Southeastern University.

@ThingsExpo Stories
For basic one-to-one voice or video calling solutions, WebRTC has proven to be a very powerful technology. Although WebRTC’s core functionality is to provide secure, real-time p2p media streaming, leveraging native platform features and server-side components brings up new communication capabilities for web and native mobile applications, allowing for advanced multi-user use cases such as video broadcasting, conferencing, and media recording.
WebRTC is about the data channel as much as about video and audio conferencing. However, basically all commercial WebRTC applications have been built with a focus on audio and video. The handling of “data” has been limited to text chat and file download – all other data sharing seems to end with screensharing. What is holding back a more intensive use of peer-to-peer data? In her session at @ThingsExpo, Dr Silvia Pfeiffer, WebRTC Applications Team Lead at National ICT Australia, looked at differ...
With major technology companies and startups seriously embracing IoT strategies, now is the perfect time to attend @ThingsExpo 2016 in New York. Learn what is going on, contribute to the discussions, and ensure that your enterprise is as "IoT-Ready" as it can be! Internet of @ThingsExpo, taking place June 6-8, 2017, at the Javits Center in New York City, New York, is co-located with 20th Cloud Expo and will feature technical sessions from a rock star conference faculty and the leading industry p...
SYS-CON Events announced today that CA Technologies has been named "Platinum Sponsor" of SYS-CON's 20th International Cloud Expo®, which will take place on June 6-8, 2017, at the Javits Center in New York City, New York, and 21st International Cloud Expo, which will take place in November in Silicon Valley, California.
The security needs of IoT environments require a strong, proven approach to maintain security, trust and privacy in their ecosystem. Assurance and protection of device identity, secure data encryption and authentication are the key security challenges organizations are trying to address when integrating IoT devices. This holds true for IoT applications in a wide range of industries, for example, healthcare, consumer devices, and manufacturing. In his session at @ThingsExpo, Lancen LaChance, vic...
SYS-CON Events announced today that delaPlex will exhibit at SYS-CON's @CloudExpo, which will take place on June 6-8, 2017, at the Javits Center in New York City, NY. delaPlex pioneered Software Development as a Service (SDaaS), which provides scalable resources to build, test, and deploy software. It’s a fast and more reliable way to develop a new product or expand your in-house team.
The explosion of new web/cloud/IoT-based applications and the data they generate are transforming our world right before our eyes. In this rush to adopt these new technologies, organizations are often ignoring fundamental questions concerning who owns the data and failing to ask for permission to conduct invasive surveillance of their customers. Organizations that are not transparent about how their systems gather data telemetry without offering shared data ownership risk product rejection, regu...
More and more brands have jumped on the IoT bandwagon. We have an excess of wearables – activity trackers, smartwatches, smart glasses and sneakers, and more that track seemingly endless datapoints. However, most consumers have no idea what “IoT” means. Creating more wearables that track data shouldn't be the aim of brands; delivering meaningful, tangible relevance to their users should be. We're in a period in which the IoT pendulum is still swinging. Initially, it swung toward "smart for smart...
The Internet of Things can drive efficiency for airlines and airports. In their session at @ThingsExpo, Shyam Varan Nath, Principal Architect with GE, and Sudip Majumder, senior director of development at Oracle, discussed the technical details of the connected airline baggage and related social media solutions. These IoT applications will enhance travelers' journey experience and drive efficiency for the airlines and the airports.
In his keynote at @ThingsExpo, Chris Matthieu, Director of IoT Engineering at Citrix and co-founder and CTO of Octoblu, focused on building an IoT platform and company. He provided a behind-the-scenes look at Octoblu’s platform, business, and pivots along the way (including the Citrix acquisition of Octoblu).
SYS-CON Events announced today that CA Technologies has been named “Platinum Sponsor” of SYS-CON's 20th International Cloud Expo®, which will take place on June 6-8, 2017, at the Javits Center in New York City, NY, and the 21st International Cloud Expo®, which will take place October 31-November 2, 2017, at the Santa Clara Convention Center in Santa Clara, CA. CA Technologies helps customers succeed in a future where every business – from apparel to energy – is being rewritten by software. From ...
In his keynote at 18th Cloud Expo, Andrew Keys, Co-Founder of ConsenSys Enterprise, provided an overview of the evolution of the Internet and the Database and the future of their combination – the Blockchain. Andrew Keys is Co-Founder of ConsenSys Enterprise. He comes to ConsenSys Enterprise with capital markets, technology and entrepreneurial experience. Previously, he worked for UBS investment bank in equities analysis. Later, he was responsible for the creation and distribution of life settle...
The best way to leverage your Cloud Expo presence as a sponsor and exhibitor is to plan your news announcements around our events. The press covering Cloud Expo and @ThingsExpo will have access to these releases and will amplify your news announcements. More than two dozen Cloud companies either set deals at our shows or have announced their mergers and acquisitions at Cloud Expo. Product announcements during our show provide your company with the most reach through our targeted audiences.
In his keynote at @ThingsExpo, Chris Matthieu, Director of IoT Engineering at Citrix and co-founder and CTO of Octoblu, focused on building an IoT platform and company. He provided a behind-the-scenes look at Octoblu’s platform, business, and pivots along the way (including the Citrix acquisition of Octoblu).
SYS-CON Events announced today that Outlyer, a monitoring service for DevOps and operations teams, has been named “Bronze Sponsor” of SYS-CON's 20th International Cloud Expo®, which will take place on June 6-8, 2017, at the Javits Center in New York City, NY. Outlyer is a monitoring service for DevOps and Operations teams running Cloud, SaaS, Microservices and IoT deployments. Designed for today's dynamic environments that need beyond cloud-scale monitoring, we make monitoring effortless so you...
20th Cloud Expo, taking place June 6-8, 2017, at the Javits Center in New York City, NY, will feature technical sessions from a rock star conference faculty and the leading industry players in the world. Cloud computing is now being embraced by a majority of enterprises of all sizes. Yesterday's debate about public vs. private has transformed into the reality of hybrid cloud: a recent survey shows that 74% of enterprises have a hybrid cloud strategy.
With major technology companies and startups seriously embracing Cloud strategies, now is the perfect time to attend @CloudExpo | @ThingsExpo, June 6-8, 2017, at the Javits Center in New York City, NY and October 31 - November 2, 2017, Santa Clara Convention Center, CA. Learn what is going on, contribute to the discussions, and ensure that your enterprise is on the right path to Digital Transformation.
Have you ever noticed how some IT people seem to lead successful, rewarding, and satisfying lives and careers, while others struggle? IT author and speaker Don Crawley uncovered the five principles that successful IT people use to build satisfying lives and careers and he shares them in this fast-paced, thought-provoking webinar. You'll learn the importance of striking a balance with technical skills and people skills, challenge your pre-existing ideas about IT customer service, and gain new in...
With 10 simultaneous tracks, keynotes, general sessions and targeted breakout classes, Cloud Expo and @ThingsExpo are two of the most important technology events of the year. Since its launch over eight years ago, Cloud Expo and @ThingsExpo have presented a rock star faculty as well as showcased hundreds of sponsors and exhibitors! In this blog post, I provide 7 tips on how, as part of our world-class faculty, you can deliver one of the most popular sessions at our events. But before reading the...
Buzzword alert: Microservices and IoT at a DevOps conference? What could possibly go wrong? In this Power Panel at DevOps Summit, moderated by Jason Bloomberg, the leading expert on architecting agility for the enterprise and president of Intellyx, panelists peeled away the buzz and discuss the important architectural principles behind implementing IoT solutions for the enterprise. As remote IoT devices and sensors become increasingly intelligent, they become part of our distributed cloud enviro...