Welcome!

Microservices Expo Authors: Flint Brenton, Liz McMillan, Pat Romanski, Elizabeth White, Charles Araujo

Related Topics: @DevOpsSummit, Microservices Expo, Linux Containers, Containers Expo Blog, @CloudExpo

@DevOpsSummit: Blog Post

Microservices and HTTP/2 By @LMacVittie | @DevOpsSummit #DevOps #Docker #Containers #Microservices

It's all about that architecture

Microservices & IoT Power Panel at @DevOpsSummit

In this Power Panel at @DevOpsSummit, moderated by Jason Bloomberg, president of Intellyx, panelists Roberto Medrano, Executive Vice President at Akana; Lori MacVittie, Evangelist for F5 Networks; and Troy Topnik, ActiveState's Technical Product Manager; and Otis Gospodnetić, founder of Sematext; 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 environment, and we must architect and code accordingly. At the very least, you'll have no problem filling in your buzzword bingo cards.

Microservices and HTTP/2
By Lori MavVittie

There's a lot of things we do to improve the performance of web and mobile applications.  We use caching. We use compression. We offload security (SSL and TLS) to a proxy with greater compute capacity.

We do all that because performance is king. Failure to perform can be, for many businesses, equivalent to an outage with increased abandonment rates and angry customers taking to the Internet to express their extreme displeasure.

The recently official HTTP/2 specification takes performance very seriously, and introduced a variety of key components designed specifically to address the need for speed. One of these was to base the newest version of the Internet's lingua franca on SPDY.

We apply image optimization and minification to content.

One of the impacts of this decision is that connections between the client (whether tethered or mobile) and the app (whether in the cloud or on big-iron) are limited to just one. One TCP connection per app. That's a huge divergence from HTTP/1 where it was typical to open 2, 4 or 6 TCP connections per site in order to take advantage of broadband. And it worked for the most part because, well, broadband. So it wouldn't be a surprise if someone interprets that ONE connection per app limitation to be a negative in terms of app performance.

There are, of course, a number of changes in the way HTTP/2 communicates over that single connection that ultimately should counteract any potential negative impact on performance from the reduction in TCP connections. The elimination of the overhead of multiple DNS lookups (not insignificant, by the way) as well as TCP-related impacts from slow start and session setup as well as a more forgiving exchange of frames under the covers is certainly a boon in terms of application performance. The ability to just push multiple responses to the client without having to play the HTTP acknowledgement game is significant in that it eliminates one of the biggest performance inhibitors of the web: latency arising from too many round trips. We've (as in the corporate We) seen gains of 2-3 times the performance of HTTP/1 with HTTP/2 during testing. And we aren't alone; there's plenty of performance testing going on out there, on the Internets, that are showing similar improvements.

Which is why it's important (very important) that we not undo all the gains of HTTP/2 with an architecture that mimics the behavior (and performance) of HTTP/1.

Domain Sharding and Microservices
Before we jump into microservices, we should review domain sharding because the concept is important when we look at how microservices are actually consumed and delivered from an HTTP point of view.

Scalability patterns (i.e. architectures) include the notion of Y-axis scale which is a sharding-based pattern. That is, it creates individual scalability domains (or clusters, if you prefer) based on some identifiable characteristic in the request. User identification (often extricated from an HTTP cookie) and URL are commonly used information upon which to shard requests and distribute them to achieve greater scalability.

An incarnation of the Y-axis scaling pattern is domain sharding. Domain sharding, for the uninitiated, is the practice of distributing content to a variety of different host names within a domain. This technique was (and probably still is) very common to overcome connection limitations imposed by HTTP/1 and its supporting browsers. You can see evidence of domain sharding when a web site uses images.example.com and scripts.example.com and static.example.com to optimize page or application load time.  Connection limitations were by host (origin server), not domain, so this technique was invaluable in achieving greater parallelization of data transfers that made it appear, at least, that pages were loading more quickly.

Which made everyone happy. Until mobile came along. Then we suddenly began to realize the detrimental impact of introducing all that extra latency (every connection requires a DNS lookup, a TCP handshake, and suffers the performance impacts of TCP slow start) on a device with much more limited processing (and network) capability. I'm not going to detail the impact; if you want to read about it in more detail I recommend reading some material from Steve Souder and Tom Daly or Mobify on the subject. Suffice to say, domain sharding has an impact on mobile performance, and it is rarely a positive one.

You might think, well, HTTP/2 is coming and all that's behind us now. Except it isn't. Microservice architectures in theory, if not in practice, are ultimately a sharding-based application architecture that, if we're not careful, can translate into a domain sharding-based network architecture that ultimately negates any of the performance gains realized by adopting HTTP/2.

That means the architectural approach you (that's you, ops) adopt to delivering microservices can have a profound impact on the performance of applications composed from those services.

The danger is not that each service will be its on (isolated and localized) "domain", because that's the whole point of microservices in the first place. The danger is that those isolated domains will be presented to the outside world as individual, isolated domains, each requiring their own personal, private connection by clients.

Even if we assume there are load balancing services in front of each service (a good assumption at this point) that still means direct connections between the client and each of the services used by the client application because the load balancing service acts as a virtual service, but does not eliminate the isolation. Each one is still its own "domain" in the sense that it requires a separate, dedicated TCP connection.

This is essentially the same thing as domain sharding as each host requires its own IP address to which the client can connect, and its behavior is counterproductive to HTTP/2*.

What we need to do to continue the benefits of a single, optimized TCP connection while being able to shard the back end is to architect a different solution in the "big black box" that is the network. To be precise, we need to take advantage of the advanced capabilities of a proxy-based load balancing service rather than a simple load balancer.

An HTTP/2 Enabling Network Architecture for Microservices
That means we need to enable a single connection between the client and the server and then utilize capabilities like Y-axis sharding (content switching, L7 load balancing, etc...) in "the network" to maintain the performance benefits of HTTP/2 to the client while enabling all the operational and development benefits of a microservices architecture.

What we can do is insert a layer 7 load balancer between the client and the local microservice load balancers. The connection on the client side maintains a single connection in the manner specified (and preferred) by HTTP/2 and requires only a single DNS lookup, one TCP session start up, and incurs the penalties from TCP slow start only once. On the service side, the layer 7 load balancer also maintains persistent connections to the local, domain load balancing services which also reduces the impact of session management on performance. Each of the local, domain load balancing services can be optimized to best distribute requests for each service. Each maintains its own algorithm and monitoring configurations which are unique to the service to ensure optimal performance.

This architecture is only minimally different from the default, but the insertion of a layer 7 load balancer capable of routing application requests based on a variety of HTTP variables (such as the cookies used for persistence or to extract user IDs or the unique verb or noun associated with a service from the URL of a RESTful API call) results in a network architecture that closely maintains the intention of HTTP/2 without requiring significant changes to a microservice based application architecture.

Essentially, we're combining X- and Y-axis scalability patterns to architect a collaborative operational architecture capable of scaling and supporting microservices without compromising on the technical aspects of HTTP/2 that were introduced to improve performance, particularly for mobile applications.

Technically speaking we're still doing sharding, but we're doing it inside the network and without breaking the one TCP connection per app specified by HTTP/2. Which means you get the best of both worlds - performance and efficiency.

Why DevOps Matters
The impact of new architectures - like microservices - on the network and the resources (infrastructure) that deliver those services is not always evident to developers or even ops. That's one of the reasons DevOps as a cultural force within IT is critical; because it engenders a breaking down of the isolated silos between ops groups that exist (all four of them) and enables greater collaboration that leads to more efficient deployment, yes, but also more efficient implementations. Implementations that don't necessarily cause performance problems that require disruptive modification to applications or services.

Collaboration in the design and architectural phases will go along way towards improving not only the efficacy of the deployment pipeline but the performance and efficiency of applications across the entire operational spectrum.

* It's not good for HTTP/1, either, as in this scenario there is essentially no difference** between HTTP/1 and HTTP/2.

** In terms of network impact. HTTP/2 still receives benefits from its native header compression and other performance benefits.

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.

Comments (0)

Share your thoughts on this story.

Add your comment
You must be signed in to add a comment. Sign-in | Register

In accordance with our Comment Policy, we encourage comments that are on topic, relevant and to-the-point. We will remove comments that include profanity, personal attacks, racial slurs, threats of violence, or other inappropriate material that violates our Terms and Conditions, and will block users who make repeated violations. We ask all readers to expect diversity of opinion and to treat one another with dignity and respect.


@MicroservicesExpo Stories
Don’t go chasing waterfall … development, that is. According to a recent post by Madison Moore on Medium featuring insights from several software delivery industry leaders, waterfall is – while still popular – not the best way to win in the marketplace. With methodologies like Agile, DevOps and Continuous Delivery becoming ever more prominent over the past 15 years or so, waterfall is old news. Or, is it? Moore cites a recent study by Gartner: “According to Gartner’s IT Key Metrics Data report, ...
In his keynote at 19th Cloud Expo, Sheng Liang, co-founder and CEO of Rancher Labs, discussed the technological advances and new business opportunities created by the rapid adoption of containers. With the success of Amazon Web Services (AWS) and various open source technologies used to build private clouds, cloud computing has become an essential component of IT strategy. However, users continue to face challenges in implementing clouds, as older technologies evolve and newer ones like Docker c...
All organizations that did not originate this moment have a pre-existing culture as well as legacy technology and processes that can be more or less amenable to DevOps implementation. That organizational culture is influenced by the personalities and management styles of Executive Management, the wider culture in which the organization is situated, and the personalities of key team members at all levels of the organization. This culture and entrenched interests usually throw a wrench in the work...
We all know that end users experience the internet primarily with mobile devices. From an app development perspective, we know that successfully responding to the needs of mobile customers depends on rapid DevOps – failing fast, in short, until the right solution evolves in your customers' relationship to your business. Whether you’re decomposing an SOA monolith, or developing a new application cloud natively, it’s not a question of using microservices - not doing so will be a path to eventual ...
The next XaaS is CICDaaS. Why? Because CICD saves developers a huge amount of time. CD is an especially great option for projects that require multiple and frequent contributions to be integrated. But… securing CICD best practices is an emerging, essential, yet little understood practice for DevOps teams and their Cloud Service Providers. The only way to get CICD to work in a highly secure environment takes collaboration, patience and persistence. Building CICD in the cloud requires rigorous ar...
"This all sounds great. But it's just not realistic." This is what a group of five senior IT executives told me during a workshop I held not long ago. We were working through an exercise on the organizational characteristics necessary to successfully execute a digital transformation, and the group was doing their ‘readout.' The executives loved everything we discussed and agreed that if such an environment existed, it would make transformation much easier. They just didn't believe it was reali...
Without lifecycle traceability and visibility across the tool chain, stakeholders from Planning-to-Ops have limited insight and answers to who, what, when, why and how across the DevOps lifecycle. This impacts the ability to deliver high quality software at the needed velocity to drive positive business outcomes. In his general session at @DevOpsSummit at 19th Cloud Expo, Eric Robertson, General Manager at CollabNet, will discuss how customers are able to achieve a level of transparency that e...
"DivvyCloud as a company set out to help customers automate solutions to the most common cloud problems," noted Jeremy Snyder, VP of Business Development at DivvyCloud, in this SYS-CON.tv interview at 20th Cloud Expo, held June 6-8, 2017, at the Javits Center in New York City, NY.
We all know that end users experience the Internet primarily with mobile devices. From an app development perspective, we know that successfully responding to the needs of mobile customers depends on rapid DevOps – failing fast, in short, until the right solution evolves in your customers' relationship to your business. Whether you’re decomposing an SOA monolith, or developing a new application cloud natively, it’s not a question of using microservices – not doing so will be a path to eventual b...
"Opsani helps the enterprise adopt containers, help them move their infrastructure into this modern world of DevOps, accelerate the delivery of new features into production, and really get them going on the container path," explained Ross Schibler, CEO of Opsani, and Peter Nickolov, CTO of Opsani, in this SYS-CON.tv interview at DevOps Summit at 21st Cloud Expo, held Oct 31 – Nov 2, 2017, at the Santa Clara Convention Center in Santa Clara, CA.
Docker is sweeping across startups and enterprises alike, changing the way we build and ship applications. It's the most prominent and widely known software container platform, and it's particularly useful for eliminating common challenges when collaborating on code (like the "it works on my machine" phenomenon that most devs know all too well). With Docker, you can run and manage apps side-by-side - in isolated containers - resulting in better compute density. It's something that many developer...
The “Digital Era” is forcing us to engage with new methods to build, operate and maintain applications. This transformation also implies an evolution to more and more intelligent applications to better engage with the customers, while creating significant market differentiators. In both cases, the cloud has become a key enabler to embrace this digital revolution. So, moving to the cloud is no longer the question; the new questions are HOW and WHEN. To make this equation even more complex, most ...
Your homes and cars can be automated and self-serviced. Why can't your storage? From simply asking questions to analyze and troubleshoot your infrastructure, to provisioning storage with snapshots, recovery and replication, your wildest sci-fi dream has come true. In his session at @DevOpsSummit at 20th Cloud Expo, Dan Florea, Director of Product Management at Tintri, provided a ChatOps demo where you can talk to your storage and manage it from anywhere, through Slack and similar services with...
What's the role of an IT self-service portal when you get to continuous delivery and Infrastructure as Code? This general session showed how to create the continuous delivery culture and eight accelerators for leading the change. Don Demcsak is a DevOps and Cloud Native Modernization Principal for Dell EMC based out of New Jersey. He is a former, long time, Microsoft Most Valuable Professional, specializing in building and architecting Application Delivery Pipelines for hybrid legacy, and cloud ...
Many organizations are now looking to DevOps maturity models to gauge their DevOps adoption and compare their maturity to their peers. However, as enterprise organizations rush to adopt DevOps, moving past experimentation to embrace it at scale, they are in danger of falling into the trap that they have fallen into time and time again. Unfortunately, we've seen this movie before, and we know how it ends: badly.
"I focus on what we are calling CAST Highlight, which is our SaaS application portfolio analysis tool. It is an extremely lightweight tool that can integrate with pretty much any build process right now," explained Andrew Siegmund, Application Migration Specialist for CAST, 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.
"We view the cloud not as a specific technology but as a way of doing business and that way of doing business is transforming the way software, infrastructure and services are being delivered to business," explained Matthew Rosen, CEO and Director at Fusion, in this SYS-CON.tv interview at 18th Cloud Expo (http://www.CloudComputingExpo.com), held June 7-9 at the Javits Center in New York City, NY.
You often hear the two titles of "DevOps" and "Immutable Infrastructure" used independently. In his session at DevOps Summit, John Willis, Technical Evangelist for Docker, covered the union between the two topics and why this is important. He provided an overview of Immutable Infrastructure then showed how an Immutable Continuous Delivery pipeline can be applied as a best practice for "DevOps." He ended the session with some interesting case study examples.
In his session at Cloud Expo, Alan Winters, U.S. Head of Business Development at MobiDev, presented a success story of an entrepreneur who has both suffered through and benefited from offshore development across multiple businesses: The smart choice, or how to select the right offshore development partner Warning signs, or how to minimize chances of making the wrong choice Collaboration, or how to establish the most effective work processes Budget control, or how to maximize project result...
Explosive growth in connected devices. Enormous amounts of data for collection and analysis. Critical use of data for split-second decision making and actionable information. All three are factors in making the Internet of Things a reality. Yet, any one factor would have an IT organization pondering its infrastructure strategy. How should your organization enhance its IT framework to enable an Internet of Things implementation? In his session at @ThingsExpo, James Kirkland, Red Hat's Chief Archi...