Welcome!

@BigDataExpo Authors: Peter Silva, Elizabeth White, Liz McMillan, Talend Inc., Pat Romanski

Related Topics: @ThingsExpo, Java IoT, @CloudExpo, @BigDataExpo, SDN Journal, OpenStack Journal

@ThingsExpo: Blog Feed Post

PubSub and Other Disruptive Emerging Network Models

What's new with software-defined architectures is not just the logical separation but the physical decoupling

When people write about software-defined architectures being "disruptive" to the network they're doing a bit of a disservice to just how much change is occurring under the hood in the engine that drives today's businesses. The notion of separating control and data planes is superficial in that it describes a general concept and it isn't really all that radical a change, if you think about it.

The control and data planes have always been separate. We have, since the need for web-scale networks came about, implemented separate topological (and usually physical) networks specifically for the purpose of segregating control traffic from the data path. The reasons for this are many: to keep management (control) traffic from interfering with the delivery of applications (and vice versa), to enable a model in which control over the critical path for applications could be secured and to ensure access to necessary control functions in the face of failure or attack.

What's new with software-defined architectures is not just the logical separation but the physical decoupling and change in component responsibility. In traditional networks there is a logically separate control plane, but it is distributed; it resides on each physical component. In software-defined networks it is physically separate but it is centralized; control responsibility resides in a single component, the "controller".

Now, OpenStack and emerging models for scaling systems that will be responsible for managing communication with and for the Internet of Things (like MQTT) use a similar control model, but it's not as active as a software-defined architectural model, it's more a passive model. That's the nature of PubSub imposing itself on the network.

PubSub Control Modelpubsub-model

PubSub (publish / subscribe) is a familiar model to application developers. It's a middleware staple that's been used for a very long time to distribute messages to a variable set of systems. In a nutshell, PubSub is based on the notion of there existing a "queue" to which authorized components can publish events or messages of interest and to which interested components an subscribe. Events or messages have a life (like a TTL) and eventually expire. In the interim, it's expected that subscribed components check the queue for messages periodically. They poll for events or messages.

The queue itself is much like a switch or router's queue, except messages in the queue are duplicated until the TTL runs out and the message expires.

PubSub is passive; that is, it does not actively distribute messages. It merely serves as a kind of centralized repository, making available to those components that need it access to relevant information about the state of applications and/or the network.

Centralized Control Model

push-modelOpenFlow-based SDN, by contrast, is active. That is, it not only serves as a centralized repository for the state of applications and/or the network, but it actively distributes messages to components based on events. For example, a controller might receive a message from another system indicating the launch of a new application instance. That event triggers a series of actions on the controller that includes informing the affected network components of configuration changes. In a passive, PubSub model, the network components themselves might be polling for such an event and, upon receiving one, would initiate the appropriate configuration changes themselves.

We can simplify the description of the differences even more: a controller-based architecture uses a push model, while a pubsub-based architecture uses a pull model. What this doesn't illustrate well is that in a push model, the centralized controller must know how to communicate the desired changes to each and every component it is controlling. That's one of the reasons original models standardized on OpenFlow and were tightly focused on L2-4 stateless networking. It could be easily standardized down to a common forwarding table.While different components might internalize that differently, the basic information was always the same: IP addresses, ports and actions.

As we move up the stack into L4-7 stateful networking, however, this model becomes more burdensome because of the complexity of rule sets and differences in policy models across such a broad set of networking domains. Hence the plug-in support in controllers like OpenDaylight for "other" control protocols. But the basic premise of the model remains the same, regardless of the control protocol: the centralized controller dictates the changes to all components. It pushes those changes to the network. Both control and execution are centralized. The controller tells components to change their configuration.

PubSub centralizes control but decentralizes execution. The control plane is still centralized; there is one authoritative system responsible for disseminating change across the network, but each individual component (or domain controller but we'll get to that in a minute) is responsible for executing the appropriate changes based on their configured policies and services. A pubsub controller never tells a component "change this now"; that's up to the individual components (or domain controller).

The Integrated Control Model

To make things even more confusing (and disruptive), these models may be used simultaneously. A software-defined architecture might be based on a centralized control model with domain controllers for specific networking functions (like security and application delivery) integrated via a pubsub-based model.

integrated-model

This is where we start seeing models that combine emerging technologies like OpenStack and SDN architectures together. OpenStack manages at the data center level, and at its heart is pubsub model that can be used by domain controllers (stateless L2-4 SDN, stateful L4-7 SDN, etc...) to receive notification of changes in the network and subsequently push those changes using the appropriate control protocols to the components it is managing.

Needless to say, the term "disruptive" is really inadequate in describing the level of change in the network required to support either models (or both). Both require significant changes not just to the network itself but the way in which the network is fundamentally provisioned and managed. It's not just a new CLI or management console, these models dramatically change the design and management of networks.

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.

@BigDataExpo Stories
SYS-CON Events announced today that Interoute, owner-operator of one of Europe's largest networks and a global cloud services platform, has been named “Bronze Sponsor” of SYS-CON's 18th Cloud Expo, which will take place on June 7-9, 2015 at the Javits Center in New York, New York. Interoute is the owner-operator of one of Europe's largest networks and a global cloud services platform which encompasses 12 data centers, 14 virtual data centers and 31 colocation centers, with connections to 195 ad...
As enterprises work to take advantage of Big Data technologies, they frequently become distracted by product-level decisions. In most new Big Data builds this approach is completely counter-productive: it presupposes tools that may not be a fit for development teams, forces IT to take on the burden of evaluating and maintaining unfamiliar technology, and represents a major up-front expense. In his session at @BigDataExpo at @ThingsExpo, Andrew Warfield, CTO and Co-Founder of Coho Data, will dis...
SYS-CON Events announced today that Commvault, a global leader in enterprise data protection and information management, has been named “Bronze Sponsor” of SYS-CON's 18th International Cloud Expo, which will take place on June 7–9, 2016, at the Javits Center in New York City, NY, and the 19th International Cloud Expo, which will take place on November 1–3, 2016, at the Santa Clara Convention Center in Santa Clara, CA. Commvault is a leading provider of data protection and information management...
It's easy to assume that your app will run on a fast and reliable network. The reality for your app's users, though, is often a slow, unreliable network with spotty coverage. What happens when the network doesn't work, or when the device is in airplane mode? You get unhappy, frustrated users. An offline-first app is an app that works, without error, when there is no network connection.
The cloud promises new levels of agility and cost-savings for Big Data, data warehousing and analytics. But it’s challenging to understand all the options – from IaaS and PaaS to newer services like HaaS (Hadoop as a Service) and BDaaS (Big Data as a Service). In her session at @BigDataExpo at @ThingsExpo, Hannah Smalltree, a director at Cazena, will provide an educational overview of emerging “as-a-service” options for Big Data in the cloud. This is critical background for IT and data profes...
Cognitive Computing is becoming the foundation for a new generation of solutions that have the potential to transform business. Unlike traditional approaches to building solutions, a cognitive computing approach allows the data to help determine the way applications are designed. This contrasts with conventional software development that begins with defining logic based on the current way a business operates. In her session at 18th Cloud Expo, Judith S. Hurwitz, President and CEO of Hurwitz & ...
SYS-CON Events announced today that VAI, a leading ERP software provider, will exhibit at SYS-CON's 18th International Cloud Expo®, which will take place on June 7-9, 2016, at the Javits Center in New York City, NY. VAI (Vormittag Associates, Inc.) is a leading independent mid-market ERP software developer renowned for its flexible solutions and ability to automate critical business functions for the distribution, manufacturing, specialty retail and service sectors. An IBM Premier Business Part...
SYS-CON Events announced today that Alert Logic, Inc., the leading provider of Security-as-a-Service solutions for the cloud, will exhibit at SYS-CON's 18th International Cloud Expo®, which will take place on June 7-9, 2016, at the Javits Center in New York City, NY. Alert Logic, Inc., provides Security-as-a-Service for on-premises, cloud, and hybrid infrastructures, delivering deep security insight and continuous protection for customers at a lower cost than traditional security solutions. Ful...
Fortunately, meaningful and tangible business cases for IoT are plentiful in a broad array of industries and vertical markets. These range from simple warranty cost reduction for capital intensive assets, to minimizing downtime for vital business tools, to creating feedback loops improving product design, to improving and enhancing enterprise customer experiences. All of these business cases, which will be briefly explored in this session, hinge on cost effectively extracting relevant data from ...
SYS-CON Events announced today that Catchpoint Systems, Inc., a provider of innovative web and infrastructure monitoring solutions, has been named “Silver Sponsor” of SYS-CON's DevOps Summit at 18th Cloud Expo New York, which will take place June 7-9, 2016, at the Javits Center in New York City, NY. Catchpoint is a leading Digital Performance Analytics company that provides unparalleled insight into customer-critical services to help consistently deliver an amazing customer experience. Designed...
With the Apple Watch making its way onto wrists all over the world, it’s only a matter of time before it becomes a staple in the workplace. In fact, Forrester reported that 68 percent of technology and business decision-makers characterize wearables as a top priority for 2015. Recognizing their business value early on, FinancialForce.com was the first to bring ERP to wearables, helping streamline communication across front and back office functions. In his session at @ThingsExpo, Kevin Roberts...
With an estimated 50 billion devices connected to the Internet by 2020, several industries will begin to expand their capabilities for retaining end point data at the edge to better utilize the range of data types and sheer volume of M2M data generated by the Internet of Things. In his session at @ThingsExpo, Don DeLoach, CEO and President of Infobright, will discuss the infrastructures businesses will need to implement to handle this explosion of data by providing specific use cases for filte...
SYS-CON Events announced today that Pythian, a global IT services company specializing in helping companies adopt disruptive technologies to optimize revenue-generating systems, has been named “Bronze Sponsor” of SYS-CON's 18th Cloud Expo, which will take place on June 7-9, 2015 at the Javits Center in New York, New York. Founded in 1997, Pythian is a global IT services company that helps companies compete by adopting disruptive technologies such as cloud, Big Data, advanced analytics, and DevO...
SYS-CON Events announced today that Fusion, a leading provider of cloud services, will exhibit at SYS-CON's 18th International Cloud Expo®, which will take place on June 7-9, 2016, at the Javits Center in New York City, NY. Fusion, a leading provider of integrated cloud solutions to small, medium and large businesses, is the industry's single source for the cloud. Fusion's advanced, proprietary cloud service platform enables the integration of leading edge solutions in the cloud, including clou...
Most people haven’t heard the word, “gamification,” even though they probably, and perhaps unwittingly, participate in it every day. Gamification is “the process of adding games or game-like elements to something (as a task) so as to encourage participation.” Further, gamification is about bringing game mechanics – rules, constructs, processes, and methods – into the real world in an effort to engage people. In his session at @ThingsExpo, Robert Endo, owner and engagement manager of Intrepid D...
With microservices, SOA and distributed architectures becoming more popular, it is becoming increasingly harder to keep track of where time is spent in a distributed application when trying to diagnose performance problems. Distributed tracing systems attempt to address this problem by following application requests across service boundaries, persisting metadata along the way that provide context for fine-grained performance monitoring.
We all know that data growth is exploding and storage budgets are shrinking. Instead of showing you charts on how much data there is, in his session at 18th Cloud Expo, Scott Cleland, Senior Director of Product Marketing for HGST, will show how to capture all of your data in one place. After you have your data under control, you can then analyze it in one place, saving time and resources. See how HGST has used these solutions to gain more value out of the information we have – and capitalize o...
Data-as-a-Service is the complete package for the transformation of raw data into meaningful data assets and the delivery of those data assets. In her session at 18th Cloud Expo, Lakshmi Randall, an industry expert, analyst and strategist, will address: What is DaaS (Data-as-a-Service)? Challenges addressed by DaaS Vendors that are enabling DaaS Architecture options for DaaS
Eighty percent of a data scientist’s time is spent gathering and cleaning up data, and 80% of all data is unstructured and almost never analyzed. Cognitive computing, in combination with Big Data, is changing the equation by creating data reservoirs and using natural language processing to enable analysis of unstructured data sources. This is impacting every aspect of the analytics profession from how data is mined (and by whom) to how it is delivered. This is not some futuristic vision: it's ha...
The IoT's basic concept of collecting data from as many sources possible to drive better decision making, create process innovation and realize additional revenue has been in use at large enterprises with deep pockets for decades. So what has changed? In his session at @ThingsExpo, Prasanna Sivaramakrishnan, Solutions Architect at Red Hat, discussed the impact commodity hardware, ubiquitous connectivity, and innovations in open source software are having on the connected universe of people, thi...