SYS-CON MEDIA Authors: Pat Romanski, Gary Arora, Zakia Bouachraoui, Yeshim Deniz, Liz McMillan

Blog Feed Post

Achieving Command and Control through Requests and Responses

I’ve been talking about layer 7 load balancing (L7 LB) since, well, for a long time. From the first inception of it back in the day when someone decided that routing requests using URIs and host headers was a pretty innovative thing to do. bifurcated-network-stateful-statelessIf you must know, that was back in 2001.

And it was innovative then. Because at the time, load balancing and routing was something addressed at layers 3 and 4 – that’s TCP/IP – in the network using routers and switches and load balancers and network architecture.  You didn’t commonly see network devices operating at L7. You just didn’t, except in the app infrastructure.  

Today you see it all the time in the network. That virtual server definition in httpd.conf that relies on HTTP host header? That’s part of L7 LB. Rewriting URLs? Part of L7 LB. Persistent (sticky) sessions? You got this, right? Right. L7 LB.

So basically I’ve spent most of this century preaching about L7 LB.

One Monday morning in May I was reading the Internet (cause I do that on Mondays) and came across a lengthy discussion of microservices and L7 LB.

Guys, I must tell you I was totally excited by this blog. I was excited by the content, by the focus on the role of L7 LB in microservices and emerging app architectures (he mentions canary deployments), and by the words the author used to seamlessly move what has been a traditionally network-focused technology into an ops-focused technology. This is, without a doubt, one of the best (and most concise) descriptions of L7 LB I’ve read on the Internet:

It’s this experience that motivated linkerd (pronounced “linker dee”), a proxy designed to give service operators command & control over traffic between services. This encompasses a variety of features including transport security, load balancing, multiplexing, timeouts, retries, and routing.

In this post, I’ll discuss linkerd’s approach to routing. Classically, routing is one of the problems that is addressed at Layers 3 and 4—TCP/IP—with hardware load balancers, BGP, DNS, iptables, etc. While these tools still have a place in the world, they’re difficult to extend to modern multi-service software systems. Instead of operating on connections and packets, we want to operate on requests and responses. Instead of IP addressees and ports, we want to operate on services and instances.

I highlighted that one part because man, there’s just so much wrapped up in that single statement I can’t even. Literally.

The concept of operating on requests and responses is the foundation of entire solution sets across security, scale, and performance. A proxy capable of inspecting requests and responses is able to note only deal with transport security (TLS/SSL offload) and load balancing, but app security, as well. Request and response inspection is a critical component of app security, scanning and scrubbing of content deep down in the payload (the JSON, the HTML, the XML) to find exploits and malicious content is the premise of a web application firewall.

And then there’s access control, which increasingly cannot simply rely on IP addresses and user names. The proliferation of cloud and roaming, mobile employees and users alike means a greater focus on controlling access to applications based on context. Which means operating on requests and being able to extract a variety of information from it that will provide richer access policies able to cross the chasm from users to things (devices).

And of course there’s scale. Scale today is not about load balancing algorithms, it’s about architecture. Application and operational architecture alike. The use of DevOps-driven deployment patterns like canary and blue-green deployments as well as sharding and partitioning architectures are critical to achieving not just the seamless scale required today but the efficacy of those architectures. L7 LB is key to these endeavors, enabling fine-grained control over the routing of requests and handling of responses between apps (micro or monolith) and users (thing and human). 

And that’s really what the aforementioned (did I mention it was awesome, already?) is talking about: L7 LB. Whether it’s hardware or software, in the cloud or on-premises, isn’t really all that important. That’s an operational detail that is (or should be) irrelevant when we’re talking about architecting a scalable application composed of “services and instances.”

I cannot reiterate often enough the importance of L7 LB as part of modern application architectures. And it’s exciting to see the dev and ops side of the world starting to shout the same thing as they encounter the operational challenges of scale and routing amidst a highly interconnected and interdependent set of services that are the foundation for apps (and business) today.

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.

Latest Stories
Every organization is facing their own Digital Transformation as they attempt to stay ahead of the competition, or worse, just keep up. Each new opportunity, whether embracing machine learning, IoT, or a cloud migration, seems to bring new development, deployment, and management models. The results are more diverse and federated computing models than any time in our history.
On-premise or off, you have powerful tools available to maximize the value of your infrastructure and you demand more visibility and operational control. Fortunately, data center management tools keep a vigil on memory contestation, power, thermal consumption, server health, and utilization, allowing better control no matter your cloud's shape. In this session, learn how Intel software tools enable real-time monitoring and precise management to lower operational costs and optimize infrastructure...
"Calligo is a cloud service provider with data privacy at the heart of what we do. We are a typical Infrastructure as a Service cloud provider but it's been designed around data privacy," explained Julian Box, CEO and co-founder of Calligo, in this SYS-CON.tv interview at 21st Cloud Expo, held Oct 31 – Nov 2, 2017, at the Santa Clara Convention Center in Santa Clara, CA.
Isomorphic Software is the global leader in high-end, web-based business applications. We develop, market, and support the SmartClient & Smart GWT HTML5/Ajax platform, combining the productivity and performance of traditional desktop software with the simplicity and reach of the open web. With staff in 10 timezones, Isomorphic provides a global network of services related to our technology, with offerings ranging from turnkey application development to SLA-backed enterprise support. Leadin...
While a hybrid cloud can ease that transition, designing and deploy that hybrid cloud still offers challenges for organizations concerned about lack of available cloud skillsets within their organization. Managed service providers offer a unique opportunity to fill those gaps and get organizations of all sizes on a hybrid cloud that meets their comfort level, while delivering enhanced benefits for cost, efficiency, agility, mobility, and elasticity.
DevOps has long focused on reinventing the SDLC (e.g. with CI/CD, ARA, pipeline automation etc.), while reinvention of IT Ops has lagged. However, new approaches like Site Reliability Engineering, Observability, Containerization, Operations Analytics, and ML/AI are driving a resurgence of IT Ops. In this session our expert panel will focus on how these new ideas are [putting the Ops back in DevOps orbringing modern IT Ops to DevOps].
Darktrace is the world's leading AI company for cyber security. Created by mathematicians from the University of Cambridge, Darktrace's Enterprise Immune System is the first non-consumer application of machine learning to work at scale, across all network types, from physical, virtualized, and cloud, through to IoT and industrial control systems. Installed as a self-configuring cyber defense platform, Darktrace continuously learns what is ‘normal' for all devices and users, updating its understa...
Enterprises are striving to become digital businesses for differentiated innovation and customer-centricity. Traditionally, they focused on digitizing processes and paper workflow. To be a disruptor and compete against new players, they need to gain insight into business data and innovate at scale. Cloud and cognitive technologies can help them leverage hidden data in SAP/ERP systems to fuel their businesses to accelerate digital transformation success.
Most organizations are awash today in data and IT systems, yet they're still struggling mightily to use these invaluable assets to meet the rising demand for new digital solutions and customer experiences that drive innovation and growth. What's lacking are potent and effective ways to rapidly combine together on-premises IT and the numerous commercial clouds that the average organization has in place today into effective new business solutions.
Concerns about security, downtime and latency, budgets, and general unfamiliarity with cloud technologies continue to create hesitation for many organizations that truly need to be developing a cloud strategy. Hybrid cloud solutions are helping to elevate those concerns by enabling the combination or orchestration of two or more platforms, including on-premise infrastructure, private clouds and/or third-party, public cloud services. This gives organizations more comfort to begin their digital tr...
Keeping an application running at scale can be a daunting task. When do you need to add more capacity? Larger databases? Additional servers? These questions get harder as the complexity of your application grows. Microservice based architectures and cloud-based dynamic infrastructures are technologies that help you keep your application running with high availability, even during times of extreme scaling. But real cloud success, at scale, requires much more than a basic lift-and-shift migrati...
David Friend is the co-founder and CEO of Wasabi, the hot cloud storage company that delivers fast, low-cost, and reliable cloud storage. Prior to Wasabi, David co-founded Carbonite, one of the world's leading cloud backup companies. A successful tech entrepreneur for more than 30 years, David got his start at ARP Instruments, a manufacturer of synthesizers for rock bands, where he worked with leading musicians of the day like Stevie Wonder, Pete Townsend of The Who, and Led Zeppelin. David has ...
Darktrace is the world's leading AI company for cyber security. Created by mathematicians from the University of Cambridge, Darktrace's Enterprise Immune System is the first non-consumer application of machine learning to work at scale, across all network types, from physical, virtualized, and cloud, through to IoT and industrial control systems. Installed as a self-configuring cyber defense platform, Darktrace continuously learns what is ‘normal' for all devices and users, updating its understa...
Dion Hinchcliffe is an internationally recognized digital expert, bestselling book author, frequent keynote speaker, analyst, futurist, and transformation expert based in Washington, DC. He is currently Chief Strategy Officer at the industry-leading digital strategy and online community solutions firm, 7Summits.
Addteq is a leader in providing business solutions to Enterprise clients. Addteq has been in the business for more than 10 years. Through the use of DevOps automation, Addteq strives on creating innovative solutions to solve business processes. Clients depend on Addteq to modernize the software delivery process by providing Atlassian solutions, create custom add-ons, conduct training, offer hosting, perform DevOps services, and provide overall support services.