Welcome!

Microservices Expo Authors: Yeshim Deniz, Elizabeth White, Pat Romanski, Jason Bloomberg, Mark Leake

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
Cloud Expo, Inc. has announced today that Andi Mann and Aruna Ravichandran have been named Co-Chairs of @DevOpsSummit at Cloud Expo Silicon Valley which will take place Oct. 31-Nov. 2, 2017, at the Santa Clara Convention Center in Santa Clara, CA. "DevOps is at the intersection of technology and business-optimizing tools, organizations and processes to bring measurable improvements in productivity and profitability," said Aruna Ravichandran, vice president, DevOps product and solutions marketing...
@DevOpsSummit at Cloud Expo taking place Oct 31 - Nov 2, 2017, at the Santa Clara Convention Center, Santa Clara, CA, is co-located with the 21st 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 ...
SYS-CON Events announced today that CA Technologies has been named "Platinum Sponsor" of SYS-CON's 21st International Cloud Expo®, which will take place October 31-November 2, 2017, at the Santa Clara Convention Center in Santa Clara, CA. CA Technologies helps customers succeed in a future where every business - from apparel to energy - is being rewritten by software. From planning to development to management to security, CA creates software that fuels transformation for companies in the applic...
What's the role of an IT self-service portal when you get to continuous delivery and Infrastructure as Code? This general session showed how to create the continuous delivery culture and eight accelerators for leading the change. Don Demcsak is a DevOps and Cloud Native Modernization Principal for Dell EMC based out of New Jersey. He is a former, long time, Microsoft Most Valuable Professional, specializing in building and architecting Application Delivery Pipelines for hybrid legacy, and cloud ...
In his session at Cloud Expo, Alan Winters, an entertainment executive/TV producer turned serial entrepreneur, presented a success story of an entrepreneur who has both suffered through and benefited from offshore development across multiple businesses: The smart choice, or how to select the right offshore development partner Warning signs, or how to minimize chances of making the wrong choice Collaboration, or how to establish the most effective work processes Budget control, or how to ma...
21st International Cloud Expo, taking place October 31 - November 2, 2017, 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. Me...
"When we talk about cloud without compromise what we're talking about is that when people think about 'I need the flexibility of the cloud' - it's the ability to create applications and run them in a cloud environment that's far more flexible,” explained Matthew Finnie, CTO of Interoute, in this SYS-CON.tv interview at 20th Cloud Expo, held June 6-8, 2017, at the Javits Center in New York City, NY.
In 2014, Amazon announced a new form of compute called Lambda. We didn't know it at the time, but this represented a fundamental shift in what we expect from cloud computing. Now, all of the major cloud computing vendors want to take part in this disruptive technology. In his session at 20th Cloud Expo, Doug Vanderweide, an instructor at Linux Academy, discussed why major players like AWS, Microsoft Azure, IBM Bluemix, and Google Cloud Platform are all trying to sidestep VMs and containers wit...
A common misconception about the cloud is that one size fits all. Companies expecting to run all of their operations using one cloud solution or service must realize that doing so is akin to forcing the totality of their business functionality into a straightjacket. Unlocking the full potential of the cloud means embracing the multi-cloud future where businesses use their own cloud, and/or clouds from different vendors, to support separate functions or product groups. There is no single cloud so...
Both SaaS vendors and SaaS buyers are going “all-in” to hyperscale IaaS platforms such as AWS, which is disrupting the SaaS value proposition. Why should the enterprise SaaS consumer pay for the SaaS service if their data is resident in adjacent AWS S3 buckets? If both SaaS sellers and buyers are using the same cloud tools, automation and pay-per-transaction model offered by IaaS platforms, then why not host the “shrink-wrapped” software in the customers’ cloud? Further, serverless computing, cl...
Hybrid IT is today’s reality, and while its implementation may seem daunting at times, more and more organizations are migrating to the cloud. In fact, according to SolarWinds 2017 IT Trends Index: Portrait of a Hybrid IT Organization 95 percent of organizations have migrated crucial applications to the cloud in the past year. As such, it’s in every IT professional’s best interest to know what to expect.
The taxi industry never saw Uber coming. Startups are a threat to incumbents like never before, and a major enabler for startups is that they are instantly “cloud ready.” If innovation moves at the pace of IT, then your company is in trouble. Why? Because your data center will not keep up with frenetic pace AWS, Microsoft and Google are rolling out new capabilities. In his session at 20th Cloud Expo, Don Browning, VP of Cloud Architecture at Turner, posited that disruption is inevitable for comp...
For most organizations, the move to hybrid cloud is now a question of when, not if. Fully 82% of enterprises plan to have a hybrid cloud strategy this year, according to Infoholic Research. The worldwide hybrid cloud computing market is expected to grow about 34% annually over the next five years, reaching $241.13 billion by 2022. Companies are embracing hybrid cloud because of the many advantages it offers compared to relying on a single provider for all of their cloud needs. Hybrid offers bala...
Containers, microservices and DevOps are all the rage lately. You can read about how great they are and how they’ll change your life and the industry everywhere. So naturally when we started a new company and were deciding how to architect our app, we went with microservices, containers and DevOps. About now you’re expecting a story of how everything went so smoothly, we’re now pushing out code ten times a day, but the reality is quite different.
"We are a monitoring company. We work with Salesforce, BBC, and quite a few other big logos. We basically provide monitoring for them, structure for their cloud services and we fit into the DevOps world" explained David Gildeh, Co-founder and CEO of Outlyer, 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.
If you cannot explicitly articulate how investing in a new technology, changing the approach or re-engineering the business process will help you achieve your customer-centric vision of the future in direct and measurable ways, you probably shouldn’t be doing it. At Intellyx, we spend a lot of time talking to technology vendors. In our conversations, we explore emerging new technologies that are either disrupting the way enterprise organizations work or that help enable those organizations to ...
For organizations that have amassed large sums of software complexity, taking a microservices approach is the first step toward DevOps and continuous improvement / development. Integrating system-level analysis with microservices makes it easier to change and add functionality to applications at any time without the increase of risk. Before you start big transformation projects or a cloud migration, make sure these changes won’t take down your entire organization.
There's a lot to gain from cloud computing, but success requires a thoughtful and enterprise focused approach. Cloud computing decouples data and information from the infrastructure on which it lies. A process that is a LOT more involved than dragging some folders from your desktop to a shared drive. Cloud computing as a mission transformation activity, not a technological one. As an organization moves from local information hosting to the cloud, one of the most important challenges is addressi...
Companies have always been concerned that traditional enterprise software is slow and complex to install, often disrupting critical and time-sensitive operations during roll-out. With the growing need to integrate new digital technologies into the enterprise to transform business processes, this concern has become even more pressing. A 2016 Panorama Consulting Solutions study revealed that enterprise resource planning (ERP) projects took an average of 21 months to install, with 57 percent of t...
Microservices are increasingly used in the development world as developers work to create larger, more complex applications that are better developed and managed as a combination of smaller services that work cohesively together for larger, application-wide functionality. Tools such as Service Fabric are rising to meet the need to think about and build apps using a piece-by-piece methodology that is, frankly, less mind-boggling than considering the whole of the application at once. Today, we'll ...