Welcome!

Cloud Security Authors: Elizabeth White, Ed Featherston, Darren Anstee, Liz McMillan, Pat Romanski

Related Topics: @CloudExpo, Microservices Expo, Containers Expo Blog, Agile Computing, Cloud Security, @BigDataExpo, 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
SYS-CON Events announced today that Commvault, a global leader in enterprise data protection and information management, has been named “Bronze Sponsor” of SYS-CON's 19th International Cloud Expo, which will take place on November 1–3, 2016, at the Santa Clara Convention Center in Santa Clara, CA. Commvault is a leading provider of data protection and information management solutions, helping companies worldwide activate their data to drive more value and business insight and to transform moder...
Personalization has long been the holy grail of marketing. Simply stated, communicate the most relevant offer to the right person and you will increase sales. To achieve this, you must understand the individual. Consequently, digital marketers developed many ways to gather and leverage customer information to deliver targeted experiences. In his session at @ThingsExpo, Lou Casal, Founder and Principal Consultant at Practicala, discussed how the Internet of Things (IoT) has accelerated our abil...
SYS-CON Events has announced today that Roger Strukhoff has been named conference chair of Cloud Expo and @ThingsExpo 2016 Silicon Valley. The 19th Cloud Expo and 6th @ThingsExpo will take place on November 1-3, 2016, at the Santa Clara Convention Center in Santa Clara, CA. "The Internet of Things brings trillions of dollars of opportunity to developers and enterprise IT, no matter how you measure it," stated Roger Strukhoff. "More importantly, it leverages the power of devices and the Interne...
Digital innovation is the next big wave of business transformation based on digital technologies of which IoT and Big Data are key components, For example: Business boundary innovation is a challenge to excavate third-party business value using IoT and BigData, like Nest Business structure innovation may propose re-building business structure from scratch, as Uber does in the taxicab industry The social model innovation is also a big challenge to the new social architecture with the design fr...
So, you bought into the current machine learning craze and went on to collect millions/billions of records from this promising new data source. Now, what do you do with them? Too often, the abundance of data quickly turns into an abundance of problems. How do you extract that "magic essence" from your data without falling into the common pitfalls? In her session at @ThingsExpo, Natalia Ponomareva, Software Engineer at Google, provided tips on how to be successful in large scale machine learning...
If you had a chance to enter on the ground level of the largest e-commerce market in the world – would you? China is the world’s most populated country with the second largest economy and the world’s fastest growing market. It is estimated that by 2018 the Chinese market will be reaching over $30 billion in gaming revenue alone. Admittedly for a foreign company, doing business in China can be challenging. Often changing laws, administrative regulations and the often inscrutable Chinese Interne...
Why do your mobile transformations need to happen today? Mobile is the strategy that enterprise transformation centers on to drive customer engagement. In his general session at @ThingsExpo, Roger Woods, Director, Mobile Product & Strategy – Adobe Marketing Cloud, covered key IoT and mobile trends that are forcing mobile transformation, key components of a solid mobile strategy and explored how brands are effectively driving mobile change throughout the enterprise.
In his session at @ThingsExpo, Kausik Sridharabalan, founder and CTO of Pulzze Systems, Inc., will focus on key challenges in building an Internet of Things solution infrastructure. He will shed light on efficient ways of defining interactions within IoT solutions, leading to cost and time reduction. He will also introduce ways to handle data and how one can develop IoT solutions that are lean, flexible and configurable, thus making IoT infrastructure agile and scalable.
Data is an unusual currency; it is not restricted by the same transactional limitations as money or people. In fact, the more that you leverage your data across multiple business use cases, the more valuable it becomes to the organization. And the same can be said about the organization’s analytics. In his session at 19th Cloud Expo, Bill Schmarzo, CTO for the Big Data Practice at EMC, will introduce a methodology for capturing, enriching and sharing data (and analytics) across the organizati...
SYS-CON Events announced today that Bsquare has been named “Silver Sponsor” of SYS-CON's @ThingsExpo, which will take place on November 1–3, 2016, at the Santa Clara Convention Center in Santa Clara, CA. For more than two decades, Bsquare has helped its customers extract business value from a broad array of physical assets by making them intelligent, connecting them, and using the data they generate to optimize business processes.
Internet of @ThingsExpo has announced today that Chris Matthieu has been named tech chair of Internet of @ThingsExpo 2016 Silicon Valley. The 6thInternet of @ThingsExpo will take place on November 1–3, 2016, at the Santa Clara Convention Center in Santa Clara, CA.
A strange thing is happening along the way to the Internet of Things, namely far too many devices to work with and manage. It has become clear that we'll need much higher efficiency user experiences that can allow us to more easily and scalably work with the thousands of devices that will soon be in each of our lives. Enter the conversational interface revolution, combining bots we can literally talk with, gesture to, and even direct with our thoughts, with embedded artificial intelligence, wh...
Video experiences should be unique and exciting! But that doesn’t mean you need to patch all the pieces yourself. Users demand rich and engaging experiences and new ways to connect with you. But creating robust video applications at scale can be complicated, time-consuming and expensive. In his session at @ThingsExpo, Zohar Babin, Vice President of Platform, Ecosystem and Community at Kaltura, will discuss how VPaaS enables you to move fast, creating scalable video experiences that reach your...
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 sett...
Cloud computing is being adopted in one form or another by 94% of enterprises today. Tens of billions of new devices are being connected to The Internet of Things. And Big Data is driving this bus. An exponential increase is expected in the amount of information being processed, managed, analyzed, and acted upon by enterprise IT. This amazing is not part of some distant future - it is happening today. One report shows a 650% increase in enterprise data by 2020. Other estimates are even higher....
SYS-CON Events announced today that SoftLayer, an IBM Company, has been named “Gold Sponsor” of SYS-CON's 18th Cloud Expo, which will take place on June 7-9, 2016, at the Javits Center in New York, New York. SoftLayer, an IBM Company, provides cloud infrastructure as a service from a growing number of data centers and network points of presence around the world. SoftLayer’s customers range from Web startups to global enterprises.
19th Cloud Expo, taking place November 1-3, 2016, at the Santa Clara Convention Center in Santa Clara, CA, will feature technical sessions from a rock star conference faculty and the leading industry players in the world. Cloud computing is now being embraced by a majority of enterprises of all sizes. Yesterday's debate about public vs. private has transformed into the reality of hybrid cloud: a recent survey shows that 74% of enterprises have a hybrid cloud strategy. Meanwhile, 94% of enterpri...
Businesses are struggling to manage the information flow and interactions between all of these new devices and things jumping on their network, and the apps and IT systems they control. The data businesses gather is only helpful if they can do something with it. In his session at @ThingsExpo, Chris Witeck, Principal Technology Strategist at Citrix, will discuss how different the impact of IoT will be for large businesses, expanding how IoT will allow large organizations to make their legacy ap...
In his general session at 18th Cloud Expo, Lee Atchison, Principal Cloud Architect and Advocate at New Relic, discussed cloud as a ‘better data center’ and how it adds new capacity (faster) and improves application availability (redundancy). The cloud is a ‘Dynamic Tool for Dynamic Apps’ and resource allocation is an integral part of your application architecture, so use only the resources you need and allocate /de-allocate resources on the fly.
SYS-CON Events announced today the Enterprise IoT Bootcamp, being held November 1-2, 2016, in conjunction with 19th Cloud Expo | @ThingsExpo at the Santa Clara Convention Center in Santa Clara, CA. Combined with real-world scenarios and use cases, the Enterprise IoT Bootcamp is not just based on presentations but with hands-on demos and detailed walkthroughs. We will introduce you to a variety of real world use cases prototyped using Arduino, Raspberry Pi, BeagleBone, Spark, and Intel Edison. Y...