Welcome!

@DevOpsSummit Authors: Yeshim Deniz, Pat Romanski, Carmen Gonzalez, Mehdi Daoudi, XebiaLabs Blog

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

@DevOpsSummit: Blog Post

Glue Records and Why They Are Crucial | @DevOpsSummit #DevOps #WebPerf

A lot has been written and discussed about Domain Name System (DNS) in the past few days

Glue Records and Why They Are Crucial
By Nilabh Mishra

A lot has been written and discussed about Domain Name System (DNS) in the past few days. The DDoS attacks on one of the major managed DNS Providers a while ago just made us all take DNS issues seriously once again.

So why so much emphasis on getting DNS Right? Like a lot of other people in this Ecosystem, we believe that DNS is not just a metric but a lifeline; a backbone for our online systems. It is extremely important to the Internet as it lays the foundation for the WWW (World Wide Web).

DNS, in simple terms, translates Host names to IP Addresses. The objective of DNS seems straight forward and simple, yet in real life, it has grown to become one of the most complex systems we have today.

All these add more complexity to an already complex system.

  • Domain Registries
  • Global Top Level Domains (gTLDs)
  • Numerous Country Code Top Level Domains (ccTLDs)
  • An ever-growing list of all the new TLDs (.space, .photography etc.)

Since DNS is not restricted to a single machine (being a distributed, coherent, and hierarchical database) and involves multiple hierarchies and entities, ensuring that every hierarchy and entity involved in managing the system is working efficiently becomes crucial. At the top of the hierarchy is:

  • Root(.)
  • gTLD servers
  • Authoritative Nameservers for domains

Every level in this hierarchy has an important role to play in the resolution process of a Domain Name:

  • The Registries (Verisign managing .COM and .NET)
  • Registrars (GoDaddy and Namecheap)
  • Registrants (those register a Domain Name)
  • ISPs
  • Managed DNS Service Providers

We all are a part of this system and it becomes extremely important for us, as Registrants, to keep an eye on how these multiple components are functioning to ensure that we have a stable and well-functioning system.

In this article, we will focus on a very important concept in DNS known as “Additional Records,” or “Glue Records.”

Additional Records or Glue Records
In simplest of terms, Glue records are A records or IP Addresses that are assigned or mapped to a Domain Name or a sub-domain. Glue records become extremely important when the Nameservers for a domain name are the sub-domains of the domain name itself.

The Glue records can be seen under the “Additional Section” of a DNS Response.

Let’s take an example to understand how Glue Records work; assume you have a domain name called “yourdomain.com” for which you are using the following set of Nameservers:

ns1. yourdomain.com

ns2. yourdomain.com

In the DNS Resolution process, the authoritative nameservers for yourdomain.com are ns1.yourdomain.com and ns2.yourdomain.com. The DNS resolution for ns1.yourdomain.com would first require the resolution of yourdomain.com, which returns the authoritative nameservers as ns1 and ns2.yourdomain.

As you may have already noticed, this creates a circular dependency, or other words a Loop, and the resolution never succeeds.

Glue records help in breaking this dependency by providing the IP Addresses for ns1.yourdomain.com and ns2.yourdomain.com in the lookup process, this breaks the loop from getting created as we no longer need to resolve the nameservers for the IP Addresses – these addresses are already provided in the form of “Glue Records”.

image2

In the example above, we see that Glue records helped remove the circular dependency by providing the A Records for ns1.ctrls.in and ns2.ctrls.in which were returned as the Authoritative Nameservers for the domain: ctrls.in. If this was not the case, the DNS Lookup would have failed because of a circular dependency.

For Domain names, which do not use sub-domains of the same domain as Authoritative Nameservers, Glue records help in reducing the number of lookups by providing the IP Addresses for the authoritative Nameservers. Here is an example for Wikipedia.com.

image1

In this case, Wikipedia.org returned ns1.wikimedia.org, ns2.wikimedia.org and ns3.wikimedia.org as the authoritative nameservers for the domain. This would have required an additional level of DNS lookup for Wikimedia.org to get the A/AAAA record for the domain name initially queried for i.e. Wikipedia.org.

One of our customers, a leading CDN provider headquartered in China, reached out to us a while ago, complaining that the A records being returned for two of their Nameservers were incorrect (Old IPs).

When investigating this case, we observed that when doing a DNS Experience test for the Nameservers, the IPs being returned by the authoritative nameservers were correct. However, when running a DNS Direct test to the Nameservers of the Domain using any of the gTLDs (a-m.gtld-servers.net.), the IPs returned were the incorrect IPs.

Digs to the domain name using the command: dig “domain name here” @a.root-servers.net returned the same response as Catchpoint’s DNS tests.

Further investigation led us to believe that this was one of those cases where the changes to the GLUE/Additional record at the Domain Registrar’s end was not pushed to the gTLD Servers.

Catchpoint DNS Monitors
Experience DNS Test For DNS tests that use the experience monitor, Catchpoint randomly selects a server from each level of the DNS route and queries it for the domain.
Direct DNS Test This test provides the complete query and response from the DNS server specified for the test along with the length of time it took to complete the test and any errors received during testing.


What fixed this issue?
Based on our recommendations, our Client reached out to the Domain Registrar for the domain and got the Glue records updated for the Domain. The change made was pushed to all the gTLD servers and the issue was resolved.

This incident emphasizes the importance of monitoring each level as well as each component of this amazingly vast system we know as DNS. Having a Monitoring strategy focused around DNS is not just recommended but is crucial to discover issues that may be under our control or out of our control.

The post Glue Records and Why They are Crucial appeared first on Catchpoint's Blog.

Read the original blog entry...

More Stories By Mehdi Daoudi

Catchpoint radically transforms the way businesses manage, monitor, and test the performance of online applications. Truly understand and improve user experience with clear visibility into complex, distributed online systems.

Founded in 2008 by four DoubleClick / Google executives with a passion for speed, reliability and overall better online experiences, Catchpoint has now become the most innovative provider of web performance testing and monitoring solutions. We are a team with expertise in designing, building, operating, scaling and monitoring highly transactional Internet services used by thousands of companies and impacting the experience of millions of users. Catchpoint is funded by top-tier venture capital firm, Battery Ventures, which has invested in category leaders such as Akamai, Omniture (Adobe Systems), Optimizely, Tealium, BazaarVoice, Marketo and many more.

@DevOpsSummit Stories
SYS-CON Events announced today that Juniper Networks (NYSE: JNPR), an industry leader in automated, scalable and secure networks, will exhibit at SYS-CON's 20th International Cloud Expo®, which will take place on June 6-8, 2017, at the Javits Center in New York City, NY. Juniper Networks challenges the status quo with products, solutions and services that transform the economics of networking. The company co-innovates with customers and partners to deliver automated, scalable and secure networks with agility, performance and value.
The 20th International Cloud Expo has announced that its Call for Papers is open. Cloud Expo, to be held June 6-8, 2017, at the Javits Center in New York City, brings together Cloud Computing, Big Data, Internet of Things, DevOps, Containers, Microservices and WebRTC to one location. With cloud computing driving a higher percentage of enterprise IT budgets every year, it becomes increasingly important to plant your flag in this fast-expanding business opportunity. Submit your speaking proposal today!
SYS-CON Events announced today that Hitachi, the leading provider the Internet of Things and Digital Transformation, will exhibit at SYS-CON's 20th International Cloud Expo®, which will take place on June 6-8, 2017, at the Javits Center in New York City, NY. Hitachi Data Systems, a wholly owned subsidiary of Hitachi, Ltd., offers an integrated portfolio of services and solutions that enable digital transformation through enhanced data management, governance, mobility and analytics. We help global organizations open new revenue streams, increase efficiencies, improve customer experience and ensure rapid time to market in the digital age. Only Hitachi Data Systems powers the digital enterprise by integrating the best information technology and operational technology from across the Hitachi family of companies. We combine this experience with Hitachi expertise in the internet of things to d...
The goal of Continuous Testing is to shift testing left to find defects earlier and release software faster. This can be achieved by integrating a set of open source functional and performance testing tools in the early stages of your software delivery lifecycle. There is one process that binds all application delivery stages together into one well-orchestrated machine: Continuous Testing. Continuous Testing is the conveyor belt between the Software Factory and production stages. Artifacts are moved from one stage to the next only after they have been tested and approved to continue. New code submitted to the repository is tested upon commit. When tests fail, the code is rejected. Subsystems are approved as part of periodic builds on their way to the delivery stage, where the system is being tested as production ready. The release process stops when tests fail. The key is to shift test ...
Back in February of 2017, Andrew Clay Schafer of Pivotal tweeted the following: “seriously tho, the whole software industry is stuck on deployment when we desperately need architecture and telemetry.” Intrigue in a 140 characters. For me, I hear Andrew saying, “we’re jumping to step 5 before we’ve successfully completed steps 1-4.”
SYS-CON Events announced today that T-Mobile will exhibit at SYS-CON's 20th International Cloud Expo®, which will take place on June 6-8, 2017, at the Javits Center in New York City, NY. As America's Un-carrier, T-Mobile US, Inc., is redefining the way consumers and businesses buy wireless services through leading product and service innovation. The Company's advanced nationwide 4G LTE network delivers outstanding wireless experiences to 67.4 million customers who are unwilling to compromise on quality and value.
SYS-CON Events announced today that Hitachi, the leading provider the Internet of Things and Digital Transformation, will exhibit at SYS-CON's 20th International Cloud Expo®, which will take place on June 6-8, 2017, at the Javits Center in New York City, NY. Hitachi Data Systems, a wholly owned subsidiary of Hitachi, Ltd., offers an integrated portfolio of services and solutions that enable digital transformation through enhanced data management, governance, mobility and analytics. We help global organizations open new revenue streams, increase efficiencies, improve customer experience and ensure rapid time to market in the digital age. Only Hitachi Data Systems powers the digital enterprise by integrating the best information technology and operational technology from across the Hitachi family of companies. We combine this experience with Hitachi expertise in the internet of things to d...
“DevOps is really about the business. The business is under pressure today, competitively in the marketplace to respond to the expectations of the customer. The business is driving IT and the problem is that IT isn't responding fast enough," explained Mark Levy, Senior Product Marketing Manager at Serena Software, in this SYS-CON.tv interview at DevOps Summit, held Nov 4–6, 2014, at the Santa Clara Convention Center in Santa Clara, CA.
20th Cloud Expo, taking place June 6-8, 2017, at the Javits Center in New York City, NY, 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.
SYS-CON Events announced today that Grape Up will exhibit at SYS-CON's 21st International Cloud Expo®, which will take place on Oct. 31 – Nov 2, 2017, at the Santa Clara Convention Center in Santa Clara, CA. Grape Up is a software company specializing in cloud native application development and professional services related to Cloud Foundry PaaS. With five expert teams that operate in various sectors of the market across the U.S. and Europe, Grape Up works with a variety of customers from emerging startups to Fortune 1000 companies.
SYS-CON Events announced today that Super Micro Computer, Inc., a global leader in compute, storage and networking technologies, will exhibit at SYS-CON's 20th International Cloud Expo®, which will take place on June 6-8, 2017, at the Javits Center in New York City, NY. Supermicro (NASDAQ: SMCI), the leading innovator in high-performance, high-efficiency server technology, is a premier provider of advanced server Building Block Solutions® for Data Center, Cloud Computing, Enterprise IT, Hadoop/Big Data, HPC and Embedded Systems worldwide. Supermicro is committed to protecting the environment through its “We Keep IT Green®” initiative and provides customers with the most energy-efficient, environmentally friendly solutions available on the market.
Everyone wants to use containers, but monitoring containers is hard. New ephemeral architecture introduces new challenges in how monitoring tools need to monitor and visualize containers, so your team can make sense of everything. In his session at @DevOpsSummit, David Gildeh, co-founder and CEO of Outlyer, will go through the challenges and show there is light at the end of the tunnel if you use the right tools and understand what you need to be monitoring to successfully use containers in your environments.
Developers want to create better apps faster. Static clouds are giving way to scalable systems, with dynamic resource allocation and application monitoring. You won't hear that chant from users on any picket line, but helping developers to create better apps faster is the mission of Lee Atchison, principal cloud architect and advocate at New Relic Inc., based in San Francisco. His singular job is to understand and drive the industry in the areas of cloud architecture, microservices, scalability and availability. In a keynote presentation, he spoke to a standing-room-only crowd at New York's Cloud Expo about how highly available, highly scalable systems can help developers attain the goal of better apps faster.
Grape Up is a software company, specialized in cloud native application development and professional services related to Cloud Foundry PaaS. With five expert teams that operate in various sectors of the market across the USA and Europe, we work with a variety of customers from emerging startups to Fortune 1000 companies.
SYS-CON Events announced today that Interoute, owner-operator of one of Europe's largest networks and a global cloud services platform, has been named “Bronze Sponsor” of SYS-CON's 20th Cloud Expo, which will take place on June 6-8, 2017 at the Javits Center in New York, New York. Interoute is the owner-operator of one of Europe's largest networks and a global cloud services platform which encompasses 12 data centers, 14 virtual data centers and 31 colocation centers, with connections to 195 additional third-party data centers across Europe. Its full-service Unified ICT platform serves international enterprises and many of the world’s leading service providers, as well as governments and universities.
@DevOpsSummit at Cloud taking place June 6-8, 2017, at Javits Center, New York City, is co-located with the 20th International Cloud Expo 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 to wait for long development cycles that produce software that is obsolete at launch. DevOps may be disruptive, but it is essential.
In recent years, containers have taken the world by storm. Companies of all sizes and industries have realized the massive benefits of containers, such as unprecedented mobility, higher hardware utilization, and increased flexibility and agility; however, many containers today are non-persistent. Containers without persistence miss out on many benefits, and in many cases simply pass the responsibility of persistence onto other infrastructure, adding additional complexity.
Cloud Expo, Inc. has announced today that Aruna Ravichandran, vice president of DevOps Product and Solutions Marketing at CA Technologies, has been named co-conference chair of DevOps at Cloud Expo 2017. The @DevOpsSummit at Cloud Expo New York will take place on June 6-8, 2017, at the Javits Center in New York City, New York, and @DevOpsSummit at Cloud Expo Silicon Valley will take place Oct. 31-Nov. 2, 2017, at the Santa Clara Convention Center in Santa Clara, CA.
Most companies are adopting or evaluating container technology - Docker in particular - to speed up application deployment, drive down cost, ease management and make application delivery more flexible overall. As with most new architectures, this dream takes a lot of work to become a reality. Even when you do get your application componentized enough and packaged properly, there are still challenges for DevOps teams to making the shift to continuous delivery and achieving that reduction in cost and increase in speed.
Translating agile methodology into real-world best practices within the modern software factory has driven widespread DevOps adoption, yet much work remains to expand workflows and tooling across the enterprise. As models evolve from pockets of experimentation into wholescale organizational reinvention, practitioners find themselves challenged to incorporate the culture and architecture necessary to support DevOps at scale. In his session at @DevOpsSummit at 20th Cloud Expo, Anand Akela, Senior Director of DevOps Solutions at CA Technologies, will discuss how existing adopters are employing unified agile and DevOps techniques to engage functional processes and toolchains that deliver increased software quality, faster time-to-market and measurably improved customer experience.
SYS-CON Events announced today that Twistlock, the leading provider of cloud container security solutions, will exhibit at SYS-CON's 20th International Cloud Expo®, which will take place on June 6-8, 2017, at the Javits Center in New York City, NY. Twistlock is the industry's first enterprise security suite for container security. Twistlock's technology addresses risks on the host and within the application of the container, enabling enterprises to consistently enforce security policies, monitor and audit activity and identify and isolate threats in a container or cluster of containers.
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 containers gain prominence. He explored these challenges and how to address them, while considering how containers will influence the direction of cloud computing.
SYS-CON Events announced today that Juniper Networks (NYSE: JNPR), an industry leader in automated, scalable and secure networks, will exhibit at SYS-CON's 20th International Cloud Expo®, which will take place on June 6-8, 2017, at the Javits Center in New York City, NY. Juniper Networks challenges the status quo with products, solutions and services that transform the economics of networking. The company co-innovates with customers and partners to deliver automated, scalable and secure networks with agility, performance and value.
SYS-CON Events announced today that CA Technologies has been named "Platinum Sponsor" of SYS-CON's 20th International Cloud Expo®, which will take place on June 6-8, 2017, at the Javits Center in New York City, New York, and 21st International Cloud Expo, which will take place in November in Silicon Valley, California.
DevOps is being widely accepted (if not fully adopted) as essential in enterprise IT. But as Enterprise DevOps gains maturity, expands scope, and increases velocity, the need for data-driven decisions across teams becomes more acute. DevOps teams in any modern business must wrangle the ‘digital exhaust’ from the delivery toolchain, "pervasive" and "cognitive" computing, APIs and services, mobile devices and applications, the Internet of Things, and now even blockchain.