Welcome!

Microservices Expo Authors: Pat Romanski, Liz McMillan, Stackify Blog, Elizabeth White, Yeshim Deniz

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.

@MicroservicesExpo Stories
SYS-CON Events announced today that Fusion, a leading provider of cloud services, 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. Fusion, a leading provider of integrated cloud solutions to small, medium and large businesses, is the industry’s single source for the cloud. Fusion’s advanced, proprietary cloud service platform enables the integration of leading edge solutions in the cloud, including cloud...
There are two main reasons for infrastructure automation. First, system administrators, IT professionals and DevOps engineers need to automate as many routine tasks as possible. That’s why we build tools at Stackify to help developers automate processes like application performance management, error monitoring, and log management; automation means you have more time for mission-critical tasks. Second, automation makes the management of complex, diverse environments possible and allows rapid scal...
Cloud promises the agility required by today’s digital businesses. As organizations adopt cloud based infrastructures and services, their IT resources become increasingly dynamic and hybrid in nature. Managing these require modern IT operations and tools. In his session at 20th Cloud Expo, Raj Sundaram, Senior Principal Product Manager at CA Technologies, will discuss how to modernize your IT operations in order to proactively manage your hybrid cloud and IT environments. He will be sharing bes...
This talk centers around how to automate best practices in a multi-/hybrid-cloud world based on our work with customers like GE, Discovery Communications and Fannie Mae. Today’s enterprises are reaping the benefits of cloud computing, but also discovering many risks and challenges. In the age of DevOps and the decentralization of IT, it’s easy to over-provision resources, forget that instances are running, or unintentionally expose vulnerabilities.
DevOps is often described as a combination of technology and culture. Without both, DevOps isn't complete. However, applying the culture to outdated technology is a recipe for disaster; as response times grow and connections between teams are delayed by technology, the culture will die. A Nutanix Enterprise Cloud has many benefits that provide the needed base for a true DevOps paradigm. In his Day 3 Keynote at 20th Cloud Expo, Chris Brown, a Solutions Marketing Manager at Nutanix, will explore t...
SYS-CON Events announced today that CollabNet, a global leader in enterprise software development, release automation and DevOps solutions, will be a Bronze Sponsor of SYS-CON's 20th International Cloud Expo®, taking place from June 6-8, 2017, at the Javits Center in New York City, NY. CollabNet offers a broad range of solutions with the mission of helping modern organizations deliver quality software at speed. The company’s latest innovation, the DevOps Lifecycle Manager (DLM), supports Value S...
SYS-CON Events announced today that Peak 10, Inc., a national IT infrastructure and cloud services provider, 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. Peak 10 provides reliable, tailored data center and network services, cloud and managed services. Its solutions are designed to scale and adapt to customers’ changing business needs, enabling them to lower costs, improve performance and focus intern...
SYS-CON Events announced today that Linux Academy, the foremost online Linux and cloud training platform and community, 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. Linux Academy was founded on the belief that providing high-quality, in-depth training should be available at an affordable price. Industry leaders in quality training, provided services, and student certification passes, its goal is to c...
It has never been a better time to be a developer! Thanks to cloud computing, deploying our applications is much easier than it used to be. How we deploy our apps continues to evolve thanks to cloud hosting, Platform-as-a-Service (PaaS), and now Function-as-a-Service. FaaS is the concept of serverless computing via serverless architectures. Software developers can leverage this to deploy an individual "function", action, or piece of business logic. They are expected to start within milliseconds...
DevOps at Cloud Expo – being held October 31 - November 2, 2017, at the Santa Clara Convention Center in Santa Clara, CA – announces that its Call for Papers is open. Born out of proven success in agile development, cloud computing, and process automation, DevOps is a macro trend you cannot afford to miss. From showcase success stories from early adopters and web-scale businesses, DevOps is expanding to organizations of all sizes, including the world's largest enterprises – and delivering real r...
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 ...
One of the biggest challenges with adopting a DevOps mentality is: new applications are easily adapted to cloud-native, microservice-based, or containerized architectures - they can be built for them - but old applications need complex refactoring. On the other hand, these new technologies can require relearning or adapting new, oftentimes more complex, methodologies and tools to be ready for production. In his general session at @DevOpsSummit at 20th Cloud Expo, Chris Brown, Solutions Marketi...
SYS-CON Events announced today that HTBase 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. HTBase (Gartner 2016 Cool Vendor) delivers a Composable IT infrastructure solution architected for agility and increased efficiency. It turns compute, storage, and fabric into fluid pools of resources that are easily composed and re-composed to meet each application’s needs. With HTBase, companies can quickly prov...
@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 developm...
With 10 simultaneous tracks, keynotes, general sessions and targeted breakout classes, Cloud Expo and @ThingsExpo are two of the most important technology events of the year. Since its launch over eight years ago, Cloud Expo and @ThingsExpo have presented a rock star faculty as well as showcased hundreds of sponsors and exhibitors! In this blog post, I provide 7 tips on how, as part of our world-class faculty, you can deliver one of the most popular sessions at our events. But before reading the...
The purpose of this article is draw attention to key SaaS services that are commonly overlooked during contact signing that are essential to ensuring they meet the expectations and requirements of the organization and provide guidance and recommendations for process and controls necessary for achieving quality SaaS contractual agreements.
SYS-CON Events announced today that OpsGenie 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. Founded in 2012, OpsGenie is an alerting and on-call management solution for dev and ops teams. OpsGenie provides the tools needed to design actionable alerts, manage on-call schedules and escalations, and ensure that the right people are notified at the right time, using multiple notification methods.
The first step to solving a problem is recognizing that it actually exists. And whether you've realized it or not, cloud services are a problem for your IT department. Even if you feel like you have a solid grasp of cloud technology and the nuances of making a cloud purchase, business leaders don't share the same confidence. Nearly 80% feel that IT lacks the skills necessary to help with cloud purchases-and they're looking to cloud brokers for help instead. It's time to admit we have a cloud s...
According to a recent Gartner study, by 2020, it will be unlikelythat any enterprise will have a “no cloud” policy, and hybrid will be the most common use of the cloud. While the benefits of leveraging public cloud infrastructures are well understood, the desire to keep critical workloads and data on-premise in the private data center still remains. For enterprises, the hybrid cloud provides a best of both worlds solution. However, the leading factor that determines the preference to the hybrid ...
In this modern world of IT, you've probably got some new colleagues in your life-namely, the cloud and SaaS providers who now hold your infrastructure in their hands. These business relationships-yes, they're technology-based, but cloud and SaaS are business models-will become as important to your IT team and your company as the hardware and software you used to install. Once you've adopted SaaS, or inherited SaaS, it's on you to avoid price hikes, licensing issues and app or provider sprawl....