Welcome!

Agile Computing Authors: Elizabeth White, Liz McMillan, Yeshim Deniz, Pat Romanski, Andy Thurai

Related Topics: @DevOpsSummit, Containers Expo Blog, Agile Computing

@DevOpsSummit: Blog Feed Post

How HTTP/2 Eliminates Technical Debt By @LMacVittie | @DevOpsSummit #DevOps

In fact, technical debt is a significant focus of the Agile methodology and is flows (quite naturally) into DevOps

Developers are – despite their attention to what is considered a very logic-based field of study – a very creative group. Give them a hurdle to overcome and they will. The problem, of course, is not that they’ve solved a problem, it’s that in doing so they’ve likely created a source of technical debt that will, over time, become problematic.

In fact, technical debt is a significant focus of the Agile methodology and is flows (quite naturally) into DevOps. That’s good, because technical debt, like real debt, compounds over time and can put a significant damper on future growth and success.

Such is the case with HTTP 1.1 or, to be precise, the limitations of HTTP 1.1. Developers, upon facing certain limitations, came up with solutions (workarounds, hacks, etc…) and put them into practice in their code. Then, thanks to the Internet, those practices were shared with other developers facing the same limitations and, ultimately, became de facto standard techniques for “getting around” those pesky protocol problems.

Three of those problems are a significant source of technical debt that’s continuing to compound interest today:

1. Domain sharding
This practice began when developers decided that the six connections per origin (host) limitation impeded on their ability to shove data at clients really, really fast. They weren’t wrong – it did – but primarily because web apps ballooned from comprising a handful of objects to well over 80 in a short period of time. Each object requires its own GET request and without more significant parallelization than was allowed by the spec, well… application experience suffered. Domain sharding simply increased the number of connections that could be used in parallel by artificially inflating the number of hosts (origins). Using CNAMEs, many new “hosts” were created, each allowed up to six connections of their own.

The technical debt here is accumulated because the code is tightly-coupled to those hosts (and there’s technical ops debt, too, in maintaining those additional CNAMEs in DNS but for today let’s just focus on the code, shall we?)  and any changes to the hosts requires changes to the application. Which is bad, because they can be spread out across a whole lot of code in a larger organization.

Domain sharding in the application itself, too, can be a burden on the network and downright horrific for mobile applications as it requires additional DNS lookups along with all the extra overhead associated with TCP connections.

HTTP/2 Answer: Request and Response Multiplexing
A new binary framing layer enables full request and response multiplexing and eliminates the need for multiple connections. Developers can return to applications that do not need to know anything about hosts or origins and can, in fact, use relative addressing to ensure greater portability across environments. Network teams, too, can breathe easier knowing they won’t need to maintain a list of CNAMEs in DNS whose only purpose is to support domain sharding.

2. Inlining
Another way to reduce the number of connections needed to transfer all the various objects required by a web app is, well, to reduce the number of objects required. One way this was (and still is) accomplished is through inlining. Basically, the objects (usual small images) are embedded in the HTML. Commonly, developers further decrease the size of these objects using base64 encoding, which can reduce images more than 30 percent.

Obviously this is a high source of technical debt, as any changes to the inlined resource must be reflected everywhere it is inlined. If the image was inlined in 5 different HTML pages… each one must be updated whenever that resource needs to be changed. Additionally, these resources cannot be cached on their own and even when compressed using base64 encoding they increase the overall size of the page, requiring more round trips between client and server that can impair app performance.

HTTP/2 Answer: Server Push
Server push is as it sounds – the ability of the server to push resources to the client. What makes this capability appealing in HTTP/2 is that it’s used to push extra objects to the client without an explicit request. So if the client requests a page, the server can respond with the page and any additional objects it wants to send along. It’s the server anticipating the request because it’s part of the page.

This eliminates the need to inline those images that are always associated with a given page in the first place, and further returns the ability to cache those images on the client to take advantage of the performance benefits when images are reused throughout a web application.

3. Concatenation
A second workaround to the problem of needing more connections was to reduce the number of connections needed by reducing the number of objects needing transfer. CSS (Cascading Style Sheets) and JavaScript files are combined into single files and smaller images are merged together into image sprites.

Technical debt is incurred here by absolutely decimating the notion of modularity. If one bundles CSS and JavaScript together, then it’s a lot harder to treat each as an individual object that can be reused by others and easily updated in the future. Changes must be merged from an “original” to the concatenated file used by the application; a process made manual by the practice of concatenation. And you know what manual processes introduce, don’t you? Yup. The potential for mistakes.

Concatenation also breaks caching and puts higher burdens on the client as larger files require more memory and more resources to parse and render.

HTTP/2 Answer: Multiplexing and Server Push
Concatenation can be eliminated as a performance-improving technique by the ability to push files in anticipation of a request and the use of multiplexed responses on the server side. Both mean a return to modular code and the use of caching (both in the network and on the client).

Technical debt may be a neologistic metaphor, but the underlying reality of choices developers (and ops) make in order to address (sometimes real and sometimes perceived) issues related to protocols and networking do have an impact on the future. It can make applications difficult to maintain, upgrade, or migrate to other environments. HTTP/2 offers a standards-based means of addressing many of the issues with HTTP 1.1 with respect to performance, and given the rising attention being paid to mobile apps – where these workarounds can really hurt performance – it’s time to start planning how to migrate to HTTP/2 to eliminate as much technical debt as possible from the past and avoid as much as possible in the future.

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.

IoT & Smart Cities Stories
DXWorldEXPO LLC announced today that All in Mobile, a mobile app development company from Poland, will exhibit at the 22nd International CloudEXPO | DXWorldEXPO. All In Mobile is a mobile app development company from Poland. Since 2014, they maintain passion for developing mobile applications for enterprises and startups worldwide.
Nicolas Fierro is CEO of MIMIR Blockchain Solutions. He is a programmer, technologist, and operations dev who has worked with Ethereum and blockchain since 2014. His knowledge in blockchain dates to when he performed dev ops services to the Ethereum Foundation as one the privileged few developers to work with the original core team in Switzerland.
Cloud-enabled transformation has evolved from cost saving measure to business innovation strategy -- one that combines the cloud with cognitive capabilities to drive market disruption. Learn how you can achieve the insight and agility you need to gain a competitive advantage. Industry-acclaimed CTO and cloud expert, Shankar Kalyana presents. Only the most exceptional IBMers are appointed with the rare distinction of IBM Fellow, the highest technical honor in the company. Shankar has also receive...
DXWorldEXPO LLC announced today that ICOHOLDER named "Media Sponsor" of Miami Blockchain Event by FinTechEXPO. ICOHOLDER gives detailed information and help the community to invest in the trusty projects. Miami Blockchain Event by FinTechEXPO has opened its Call for Papers. The two-day event will present 20 top Blockchain experts. All speaking inquiries which covers the following information can be submitted by email to [email protected] Miami Blockchain Event by FinTechEXPOalso offers sp...
Headquartered in Plainsboro, NJ, Synametrics Technologies has provided IT professionals and computer systems developers since 1997. Based on the success of their initial product offerings (WinSQL and DeltaCopy), the company continues to create and hone innovative products that help its customers get more from their computer applications, databases and infrastructure. To date, over one million users around the world have chosen Synametrics solutions to help power their accelerated business or per...
DXWordEXPO New York 2018, colocated with CloudEXPO New York 2018 will be held November 11-13, 2018, in New York City and will bring together Cloud Computing, FinTech and Blockchain, Digital Transformation, Big Data, Internet of Things, DevOps, AI, Machine Learning and WebRTC to one location.
@DevOpsSummit at Cloud Expo, taking place November 12-13 in New York City, NY, is co-located with 22nd international CloudEXPO | first international DXWorldEXPO and will feature technical sessions from a rock star conference faculty and the leading industry players in the world. The widespread success of cloud computing is driving the DevOps revolution in enterprise IT. Now as never before, development teams must communicate and collaborate in a dynamic, 24/7/365 environment. There is no time t...
When talking IoT we often focus on the devices, the sensors, the hardware itself. The new smart appliances, the new smart or self-driving cars (which are amalgamations of many ‘things'). When we are looking at the world of IoT, we should take a step back, look at the big picture. What value are these devices providing. IoT is not about the devices, its about the data consumed and generated. The devices are tools, mechanisms, conduits. This paper discusses the considerations when dealing with the...
Charles Araujo is an industry analyst, internationally recognized authority on the Digital Enterprise and author of The Quantum Age of IT: Why Everything You Know About IT is About to Change. As Principal Analyst with Intellyx, he writes, speaks and advises organizations on how to navigate through this time of disruption. He is also the founder of The Institute for Digital Transformation and a sought after keynote speaker. He has been a regular contributor to both InformationWeek and CIO Insight...
Digital Transformation is much more than a buzzword. The radical shift to digital mechanisms for almost every process is evident across all industries and verticals. This is often especially true in financial services, where the legacy environment is many times unable to keep up with the rapidly shifting demands of the consumer. The constant pressure to provide complete, omnichannel delivery of customer-facing solutions to meet both regulatory and customer demands is putting enormous pressure on...