Welcome!

Cloud Security Authors: Elizabeth White, Liz McMillan, Yeshim Deniz, Ed Featherston, Pat Romanski

Related Topics: @CloudExpo, Microservices Expo, Containers Expo Blog, Agile Computing, Cloud Security, @DXWorldExpo, SDN Journal

@CloudExpo: Blog Feed Post

Cloud: Impact of DNS on Performance

Developers and operations must work together to mitigate the impact of hybrid architectures on application performance

One of the ramifications of relying on off-premise cloud infrastructure is that you're necessarily stuck with some of the idiosyncrasies that come with it. For example, it's not your network, and thus topologically-related identifiers such as host names and IP address are not within your purview. But you certainly aren't going to ask your customers to visit "host111-east-virginia-zone3-subnet5.cloudproivder.com". At least not if you want them visit, you won't.

Luckily, you control your own DNS destiny, so you'll just CNAME that crazy long host name provided by the provider to be something more catchy and inline with your branding, say, "coolappz.com".

While certainly more appealing to everyone (easy to remember, fits better on a bumper sticker and on branded swag) it does have a downside: double the latency.

You see, CNAME lookups require two distinct DNS queries to resolve - the first retrieves the ultra-ugly-long host name, the second resolves the ultra-ugly-long host name into an IP address that can actually be used by the browser to connect.

So that's double the lookup, double the roundtrips, double the latency.

Of course, no web page comprises just one host. That would be so 90s and this, this is the 21st century! This is Web 2.0, the age of integration and interconnection and inter-everything. And if the services upon which you rely to build that web app are using CNAMEs, too, well... I hope you like math cause you're going to be added up some roundtrips and latency for a while.

The point here is not to scare you off of hybrid architectures due to the potential impact on performance, but rather to remind you to keep the impact in the fore. It is important to remember the impact of topology, proximity, and the technology in general on the overall performance of your web applications.

A Google Developers article nails down where DNS latency comes from quite well:

There are two components to DNS latency:

  • - Latency between the client (user) and DNS resolving server. In most cases this is largely due to the usual round-trip time (RTT) constraints in networked systems: geographical distance between client and server machines; network congestion; packet loss and long retransmit delays (one second on average); overloaded servers, denial-of-service attacks and so on.
  • - Latency between resolving servers and other nameservers. This source of latency is caused primarily by the following factors:
    • - Cache misses. If a response cannot be served from a resolver's cache, but requires recursively querying other nameservers, the added network latency is considerable, especially if the authoritative servers are geographically remote.
    • - Underprovisioning. If DNS resolvers are overloaded, they must queue DNS resolution requests and responses, and may begin dropping and retransmitting packets.
    • - Malicious traffic. Even if a DNS service is overprovisioned, DoS traffic can place undue load on the servers. Similarly, Kaminsky-style attacks can involve flooding resolvers with queries that are guaranteed to bypass the cache and require outgoing requests for resolution.

-- Introduction: causes and mitigations of DNS latency

Interestingly, Google is arguing for public DNS services, even though this may in fact contribute to location-induced DNS latency, particularly for custom domains for which the authoritative zone is served by relatively few number of DNS servers, most of which are geographically located far from the majority of users. Intercontinental latency is still very much problematic.

Catchpoint, a web performance monitoring service, mentions this in its exhaustive list of the ways in which DNS impacts performance:

Exotic Domains: be careful with the exotic domain names, .ly, .tv… these domains have authoritative servers that are often far away from you end user ISPs. The records will have almost always 2 day TTL, however you never know when someone will be impacted because the query has to go to the authoritative servers and they fail. Example “.ly”, 2 authoritative servers are in Libya, 2 in the US, and 1 in the Netherlands.

So when we go connecting clouds and data centers, we need to be concerned with where and how domains are being disseminated, sharded, and resolved. We need to more carefully consider how we are referencing content and whether or not the performance boosts we get from some techniques (such as domain sharding) are being offset by the impact of double the latency from the need to resolve those extra hosts.

We need to examine that in the context of other contributing factors, such as TTL (time to live). If the time to live is long enough, then perhaps the initial hit from the extra lookup required to resolve a CNAME isn't going to matter over the life of the session. If we're looking at supporting a stateless API in which sessions don't really exist, then the second lookup may indeed be problematic, but only if the calls are generally spread out over a time interval that is greater than the TTL.

It's a balancing act, where understanding how application network services contribute to the performance of applications is critical to pushing the right buttons and twisting the right knobs will alleviate performance issues that can damage adoption and growth of the web applications that are key to business.

You're Not Off The Hook, Developers

So often it's the case that applications are written with a specific behavior in mind and it is left to devops to figure out how to mitigate these kinds of potential performance issues. But it is just as important for developers to understand how the application network services contribute to performance because sometimes, all it takes is for the application to be "tweaked' with respect to an update interval or use of a different host name to generate a significant improvement in performance. It is increasingly difficult for - and sometimes even impossible - for operations to make adjustments in the infrastructure, particularly in hybrid environments where infrastructure services are black-box and off-limits.

Thus, it is of growing importance that developers and operations work together to map the interaction of applications with application network services such that each group can make appropriate modifications and configuration changes that serve to improve the overall performance of the application, no matter where it might be deployed.

As more and more organizations adopt hybrid, distributed applications that span geographies in addition to environments, this level of cooperation and collaboration will be key to managing web application performance issues.

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.

@ThingsExpo Stories
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...
DXWorldEXPO LLC, the producer of the world's most influential technology conferences and trade shows has announced the 22nd International CloudEXPO | DXWorldEXPO "Early Bird Registration" is now open. Register for Full Conference "Gold Pass" ▸ Here (Expo Hall ▸ Here)
Join IBM November 1 at 21st Cloud Expo at the Santa Clara Convention Center in Santa Clara, CA, and learn how IBM Watson can bring cognitive services and AI to intelligent, unmanned systems. Cognitive analysis impacts today’s systems with unparalleled ability that were previously available only to manned, back-end operations. Thanks to cloud processing, IBM Watson can bring cognitive services and AI to intelligent, unmanned systems. Imagine a robot vacuum that becomes your personal assistant tha...
"MobiDev is a software development company and we do complex, custom software development for everybody from entrepreneurs to large enterprises," explained Alan Winters, U.S. Head of Business Development at MobiDev, 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.
I think DevOps is now a rambunctious teenager - it's starting to get a mind of its own, wanting to get its own things but it still needs some adult supervision," explained Thomas Hooker, VP of marketing at CollabNet, in this SYS-CON.tv interview at DevOps Summit at 20th Cloud Expo, held June 6-8, 2017, at the Javits Center in New York City, NY.
Recently, WebRTC has a lot of eyes from market. The use cases of WebRTC are expanding - video chat, online education, online health care etc. Not only for human-to-human communication, but also IoT use cases such as machine to human use cases can be seen recently. One of the typical use-case is remote camera monitoring. With WebRTC, people can have interoperability and flexibility for deploying monitoring service. However, the benefit of WebRTC for IoT is not only its convenience and interopera...
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...
It is of utmost importance for the future success of WebRTC to ensure that interoperability is operational between web browsers and any WebRTC-compliant client. To be guaranteed as operational and effective, interoperability must be tested extensively by establishing WebRTC data and media connections between different web browsers running on different devices and operating systems. In his session at WebRTC Summit at @ThingsExpo, Dr. Alex Gouaillard, CEO and Founder of CoSMo Software, presented ...
WebRTC is great technology to build your own communication tools. It will be even more exciting experience it with advanced devices, such as a 360 Camera, 360 microphone, and a depth sensor camera. In his session at @ThingsExpo, Masashi Ganeko, a manager at INFOCOM Corporation, introduced two experimental projects from his team and what they learned from them. "Shotoku Tamago" uses the robot audition software HARK to track speakers in 360 video of a remote party. "Virtual Teleport" uses a multip...
Business professionals no longer wonder if they'll migrate to the cloud; it's now a matter of when. The cloud environment has proved to be a major force in transitioning to an agile business model that enables quick decisions and fast implementation that solidify customer relationships. And when the cloud is combined with the power of cognitive computing, it drives innovation and transformation that achieves astounding competitive advantage.
Data is the fuel that drives the machine learning algorithmic engines and ultimately provides the business value. In his session at Cloud Expo, Ed Featherston, a director and senior enterprise architect at Collaborative Consulting, discussed the key considerations around quality, volume, timeliness, and pedigree that must be dealt with in order to properly fuel that engine.
IoT is rapidly becoming mainstream as more and more investments are made into the platforms and technology. As this movement continues to expand and gain momentum it creates a massive wall of noise that can be difficult to sift through. Unfortunately, this inevitably makes IoT less approachable for people to get started with and can hamper efforts to integrate this key technology into your own portfolio. There are so many connected products already in place today with many hundreds more on the h...
When shopping for a new data processing platform for IoT solutions, many development teams want to be able to test-drive options before making a choice. Yet when evaluating an IoT solution, it’s simply not feasible to do so at scale with physical devices. Building a sensor simulator is the next best choice; however, generating a realistic simulation at very high TPS with ease of configurability is a formidable challenge. When dealing with multiple application or transport protocols, you would be...
Detecting internal user threats in the Big Data eco-system is challenging and cumbersome. Many organizations monitor internal usage of the Big Data eco-system using a set of alerts. This is not a scalable process given the increase in the number of alerts with the accelerating growth in data volume and user base. Organizations are increasingly leveraging machine learning to monitor only those data elements that are sensitive and critical, autonomously establish monitoring policies, and to detect...
In his keynote at 18th Cloud Expo, Andrew Keys, Co-Founder of ConsenSys Enterprise, provided an overview of the evolution of the Internet and the Database and the future of their combination – the Blockchain. Andrew Keys is Co-Founder of ConsenSys Enterprise. He comes to ConsenSys Enterprise with capital markets, technology and entrepreneurial experience. Previously, he worked for UBS investment bank in equities analysis. Later, he was responsible for the creation and distribution of life settl...
In his session at @ThingsExpo, Dr. Robert Cohen, an economist and senior fellow at the Economic Strategy Institute, presented the findings of a series of six detailed case studies of how large corporations are implementing IoT. The session explored how IoT has improved their economic performance, had major impacts on business models and resulted in impressive ROIs. The companies covered span manufacturing and services firms. He also explored servicification, how manufacturing firms shift from se...
DevOpsSummit New York 2018, colocated with CloudEXPO | DXWorldEXPO New York 2018 will be held November 11-13, 2018, in New York City. Digital Transformation (DX) is a major focus with the introduction of DXWorldEXPO within the program. Successful transformation requires a laser focus on being data-driven and on using all the tools available that enable transformation if they plan to survive over the long term. A total of 88% of Fortune 500 companies from a generation ago are now out of bus...
The Jevons Paradox suggests that when technological advances increase efficiency of a resource, it results in an overall increase in consumption. Writing on the increased use of coal as a result of technological improvements, 19th-century economist William Stanley Jevons found that these improvements led to the development of new ways to utilize coal. In his session at 19th Cloud Expo, Mark Thiele, Chief Strategy Officer for Apcera, compared the Jevons Paradox to modern-day enterprise IT, examin...
IoT solutions exploit operational data generated by Internet-connected smart “things” for the purpose of gaining operational insight and producing “better outcomes” (for example, create new business models, eliminate unscheduled maintenance, etc.). The explosive proliferation of IoT solutions will result in an exponential growth in the volume of IoT data, precipitating significant Information Governance issues: who owns the IoT data, what are the rights/duties of IoT solutions adopters towards t...
Amazon started as an online bookseller 20 years ago. Since then, it has evolved into a technology juggernaut that has disrupted multiple markets and industries and touches many aspects of our lives. It is a relentless technology and business model innovator driving disruption throughout numerous ecosystems. Amazon’s AWS revenues alone are approaching $16B a year making it one of the largest IT companies in the world. With dominant offerings in Cloud, IoT, eCommerce, Big Data, AI, Digital Assista...