|By Lori MacVittie||
|April 25, 2014 09:00 AM EDT||
Way back in the early days of the Internet scalability was an issue (the more things change...). One of the answers to this problem was to scale out web servers using a fairly well-proven concept called load balancing. Simply put, distribute the load across web servers to make sure everyone gets served in a timely fashion. We see this in action at stores every day when more checkout lines are added as demand increases. Well, we hope we see this in action. Too often we don't, much to our chagrin.
Anyway, the way in which early load balancing worked was simply to take a couple variables (IP address and TCP port) and then hash them together and stick them in the equivalent of a queue for a web server. Because hash values tend to distribute fairly evenly, this worked well (until we ran into the mega-proxy issue, thanks to folks like Compuserve and AOL).
This is called "network load balancing" because, well, it uses network variables to distribute load. It's quite fast, actually, because it's based on variables that are in fixed locations within a single packet: source or destination IP and TCP port. All the work is on the ingress, on the inbound side, and once the decision has been made it's a pretty simple thing to hash future packets and match it up before sending it on its way. Voila. Network load balancing.
Application load balancing, however, arose because network load balancing was all based on inbound variables. It couldn't take into consideration how loaded the chosen server was, or whether its response time was falling within acceptable business parameters, or whether it was at capacity or not. Those variables were all on the server side, and required visibility into the application, not the client.
It also couldn't account for the fact that virtual servers were popping up everywhere (multiple applications served from the same IP address and port) and forced the web server to become a load balancer itself. Which, if you think about it, was kind of crazy. If a single server couldn't scale well enough to meet demand, how is putting a single server in front of them going to help the situation?
Application load balancing (which has also been given other fancy names over the years like content switching or routing, application switching, application or page routing, etc...) is really focused on distributing load across applications intelligently. While it can use ingress variables like IP address and port, it generally doesn't because that doesn't offer the insight into which server (application, web, virtual, whatever) is going to be able to respond (has capacity) in a time frame acceptable to the business (response time) for a specific application (or piece of the application like images).
The difference between the two lies primarily in the variables used to distribute load. Network load balancing relies solely on network variables while Application load balancing relies mainly on application variables.
This change in load balancing techniques opened up all sorts of new efficiencies and scalability options because it allowed architectures to specialize - route requests for images to servers focused on serving images, requests for static content to servers focused on serving static content, etc...). It also enabled persistence (sticky sessions) which greatly accelerated the ability to scale out stateful applications in a web format.
Why Is It Important to SDN?
The reason this is important to SDN architectures is because layer 3 switches can, in fact, support network load balancing. Fairly easily, in fact. If you look at how Link Aggregation (trunking) is implemented in most switches, you'll see it's using network load balancing techniques to distribute load across trunked links and that the algorithms used are pretty much the same ones we used back in the day to load balancing servers based on network variables. The hash is pretty simple (and easily implemented) and doesn't require storing state because the hash is always based on the same variables, easily extracted from IP and TCP headers, and don't really tax the system. Forwarding tables are basically sets of inbound IP addresses, TCP ports and (switch) ports matched to outbound IP addresses, TCP ports and (switch) ports. So you can see that network load balancing wouldn't overly tax a controller (it just has to hash the right values and insert a forwarding entry) or a switch.
But it wouldn't be application centric, or be able to take into consideration things that modern load balancing services care about - like application status, connection capacity, and response times, not to mention enabling specialization of services. But in order to be application centric application load balancing must participate in the data path and have visibility into variables that aren't available in packets - they're in payloads and in the application server (instances) itself. Like the implications of being stateful versus stateless, the burden on a centralized controller would be overwhelming.
Thus while SDN principles are certainly applicable, the same architecture used to implement SDN for lower order network layer services is not going to be the same architecture used to implement SDN for higher order network layer services. When evaluating SDN solutions, it's again important to consider how any two SDN network (core and application) architectures complement one another, integrate with one another, and collaborate to enable a complete software-defined network architecture that supports the unique needs of both layer 2-3 and layer 4-7.
SYS-CON Events announced today that G2G3 will exhibit at SYS-CON's @DevOpsSummit Silicon Valley, which will take place on November 3–5, 2015, at the Santa Clara Convention Center in Santa Clara, CA. Based on a collective appreciation for user experience, design, and technology, G2G3 is uniquely qualified and motivated to redefine how organizations and people engage in an increasingly digital world.
Aug. 31, 2015 11:00 PM EDT Reads: 505
Any Ops team trying to support a company in today’s cloud-connected world knows that a new way of thinking is required – one just as dramatic than the shift from Ops to DevOps. The diversity of modern operations requires teams to focus their impact on breadth vs. depth. In his session at DevOps Summit, Adam Serediuk, Director of Operations at xMatters, Inc., will discuss the strategic requirements of evolving from Ops to DevOps, and why modern Operations has begun leveraging the “NoOps” approa...
Aug. 31, 2015 10:30 PM EDT Reads: 406
Too often with compelling new technologies market participants become overly enamored with that attractiveness of the technology and neglect underlying business drivers. This tendency, what some call the “newest shiny object syndrome,” is understandable given that virtually all of us are heavily engaged in technology. But it is also mistaken. Without concrete business cases driving its deployment, IoT, like many other technologies before it, will fade into obscurity.
Aug. 31, 2015 09:00 PM EDT Reads: 375
Organizations from small to large are increasingly adopting cloud solutions to deliver essential business services at a much lower cost. According to cyber security experts, the frequency and severity of cyber-attacks are on the rise, causing alarm to businesses and customers across a variety of industries. To defend against exploits like these, a company must adopt a comprehensive security defense strategy that is designed for their business. In 2015, organizations such as United Airlines, Sony...
Aug. 31, 2015 07:15 PM EDT Reads: 489
Amazon and Google have built software-defined data centers (SDDCs) that deliver massively scalable services with great efficiency. Yet, building SDDCs has proven to be a near impossibility for ‘normal’ companies without hyper-scale resources. In his session at 17th Cloud Expo, David Cauthron, founder and chief executive officer of Nimboxx, will discuss the evolution of virtualization (hardware, application, memory, storage) and how commodity / open source hyper converged infrastructure (HCI) so...
Aug. 31, 2015 04:45 PM EDT
In their Live Hack” presentation at 17th Cloud Expo, Stephen Coty and Paul Fletcher, Chief Security Evangelists at Alert Logic, will provide the audience with a chance to see a live demonstration of the common tools cyber attackers use to attack cloud and traditional IT systems. This “Live Hack” uses open source attack tools that are free and available for download by anybody. Attendees will learn where to find and how to operate these tools for the purpose of testing their own IT infrastructu...
Aug. 31, 2015 04:30 PM EDT Reads: 469
The web app is agile. The REST API is agile. The testing and planning are agile. But alas, data infrastructures certainly are not. Once an application matures, changing the shape or indexing scheme of data often forces at best a top down planning exercise and at worst includes schema changes that force downtime. The time has come for a new approach that fundamentally advances the agility of distributed data infrastructures. Come learn about a new solution to the problems faced by software organ...
Aug. 31, 2015 04:30 PM EDT
IBM’s Blue Box Cloud, powered by OpenStack, is now available in any of IBM’s globally integrated cloud data centers running SoftLayer infrastructure. Less than 90 days after its acquisition of Blue Box, IBM has integrated its Blue Box Cloud Dedicated private-cloud-as-a-service into its broader portfolio of OpenStack® based solutions. The announcement, made today at the OpenStack Silicon Valley event, further highlights IBM’s continued support to deliver OpenStack solutions across all cloud depl...
Aug. 31, 2015 03:00 PM EDT Reads: 254
Red Hat is investing in Tesora, the number one contributor to OpenStack Trove Database as a Service (DBaaS) also ranked among the top 20 companies contributing to OpenStack overall. Tesora, the company bringing OpenStack Trove Database as a Service (DBaaS) to the enterprise, has announced that Red Hat and others have invested in the company as a part of Tesora's latest funding round. The funding agreement expands on the ongoing collaboration between Tesora and Red Hat, which dates back to Febr...
Aug. 31, 2015 02:45 PM EDT Reads: 384
The Internet of Things (IoT) is about the digitization of physical assets including sensors, devices, machines, gateways, and the network. It creates possibilities for significant value creation and new revenue generating business models via data democratization and ubiquitous analytics across IoT networks. The explosion of data in all forms in IoT requires a more robust and broader lens in order to enable smarter timely actions and better outcomes. Business operations become the key driver of I...
Aug. 31, 2015 02:30 PM EDT Reads: 425
With the proliferation of connected devices underpinning new Internet of Things systems, Brandon Schulz, Director of Luxoft IoT – Retail, will be looking at the transformation of the retail customer experience in brick and mortar stores in his session at @ThingsExpo. Questions he will address include: Will beacons drop to the wayside like QR codes, or be a proximity-based profit driver? How will the customer experience change in stores of all types when everything can be instrumented and a...
Aug. 31, 2015 02:30 PM EDT Reads: 467
WSM International, the pioneer and leader in server migration services, has announced an agreement with WHOA.com, a leader in providing secure public, private and hybrid cloud computing services. Under terms of the agreement, WSM will provide migration services to WHOA.com customers to relocate some or all of their applications, digital assets, and other computing workloads to WHOA.com enterprise-class, secure cloud infrastructure. The migration services include detailed evaluation and planning...
Aug. 31, 2015 02:00 PM EDT Reads: 188
SYS-CON Events announced today that DataClear Inc. will exhibit at the 17th International Cloud Expo®, which will take place on November 3–5, 2015, at the Santa Clara Convention Center in Santa Clara, CA. The DataClear ‘BlackBox’ is the only solution that moves your PC, browsing and data out of the United States and away from prying (and spying) eyes. Its solution automatically builds you a clean, on-demand, virus free, new virtual cloud based PC outside of the United States, and wipes it clean...
Aug. 31, 2015 01:45 PM EDT Reads: 429
Culture is the most important ingredient of DevOps. The challenge for most organizations is defining and communicating a vision of beneficial DevOps culture for their organizations, and then facilitating the changes needed to achieve that. Often this comes down to an ability to provide true leadership. As a CIO, are your direct reports IT managers or are they IT leaders? The hard truth is that many IT managers have risen through the ranks based on their technical skills, not their leadership ab...
Aug. 31, 2015 12:30 PM EDT Reads: 364
SYS-CON Events announced today that HPM Networks will exhibit at the 17th International Cloud Expo®, which will take place on November 3–5, 2015, at the Santa Clara Convention Center in Santa Clara, CA. For 20 years, HPM Networks has been integrating technology solutions that solve complex business challenges. HPM Networks has designed solutions for both SMB and enterprise customers throughout the San Francisco Bay Area.
Aug. 31, 2015 11:30 AM EDT Reads: 899
SYS-CON Events announced today that Micron Technology, Inc., a global leader in advanced semiconductor systems, will exhibit at the 17th International Cloud Expo®, which will take place on November 3–5, 2015, at the Santa Clara Convention Center in Santa Clara, CA. Micron’s broad portfolio of high-performance memory technologies – including DRAM, NAND and NOR Flash – is the basis for solid state drives, modules, multichip packages and other system solutions. Backed by more than 35 years of tech...
Aug. 31, 2015 11:15 AM EDT Reads: 235
Introducing Containers & Microservices Bootcamp at @CloudExpo Silicon Valley | #Containers #Microservices
SYS-CON Events announced today the Containers & Microservices Bootcamp, being held November 3-4, 2015, in conjunction with 17th Cloud Expo, @ThingsExpo, and @DevOpsSummit at the Santa Clara Convention Center in Santa Clara, CA. This is your chance to get started with the latest technology in the industry. Combined with real-world scenarios and use cases, the Containers and Microservices Bootcamp, led by Janakiram MSV, a Microsoft Regional Director, will include presentations as well as hands-on...
Aug. 31, 2015 10:45 AM EDT Reads: 353
Through WebRTC, audio and video communications are being embedded more easily than ever into applications, helping carriers, enterprises and independent software vendors deliver greater functionality to their end users. With today’s business world increasingly focused on outcomes, users’ growing calls for ease of use, and businesses craving smarter, tighter integration, what’s the next step in delivering a richer, more immersive experience? That richer, more fully integrated experience comes ab...
Aug. 31, 2015 10:30 AM EDT Reads: 670
SYS-CON Events announced today that Pythian, a global IT services company specializing in helping companies leverage disruptive technologies to optimize revenue-generating systems, has been named “Bronze Sponsor” of SYS-CON's 17th Cloud Expo, which will take place on November 3–5, 2015, at the Santa Clara Convention Center in Santa Clara, CA. Founded in 1997, Pythian is a global IT services company that helps companies compete by adopting disruptive technologies such as cloud, Big Data, advance...
Aug. 31, 2015 10:15 AM EDT Reads: 312
Cloud and datacenter migration innovator AppZero has joined the Microsoft Enterprise Cloud Alliance Program. AppZero is a fast, flexible way to move Windows Server applications from any source machine – physical or virtual – to any destination server, in any cloud or datacenter, using its patented container technology. AppZero’s container is also called a Virtual Application Appliance (VAA). To facilitate Microsoft Azure onboarding, AppZero has two purpose-built offerings: AppZero SP for Azure,...
Aug. 31, 2015 10:15 AM EDT Reads: 198