Welcome!

Agile Computing Authors: Elizabeth White, David H Deans, Fouad Khalil, Dana Gardner, Liz McMillan

Blog Feed Post

Why you should build an Immutable Infrastructure

Why you should build an Immutable Infrastructure – by Florian Motlik, CTO of Codeship

Some of the major challenges today when building infrastructure are predictability, scalability and automated recovery. A predictable system will promote the exact same artifact that you tested into your production system so no intermittent failure can cause any trouble. A scalable system make it trivial, especially automatically, to deal with any rise in traffic. And automated recovery will make sure your team can focus on building a better product and sleep during the night instead of maintaining infrastructure constantly.

At Codeship we’ve found that an Infrastructure made up of immutable components has helped us tremendously with these goals.

Julian Dunn from Chef recently released a blog post about their stance on immutable infrastructure.

Chad Fowler summed it up very well in a tweet

Instead of going over every piece of the article, I want to present an overview of the experience we – and others – have had in making parts of our infrastructure immutable.

What is Immutable Infrastructure

Immutable infrastructure is comprised of immutable components that are replaced for every deployment, rather than being updated in-place. Those components are started from a common image that is built once per deployment and can be tested and validated. The common image can be built through automation, but doesn’t have to be. Immutability is independent of any tool or workflow for building the images.

Its best use case is in a cloud or virtualized environment. While it’s possible in non-virtualized environments, the benefit doesn’t outweigh the effort.

State Isolation

The main criticism against immutable infrastructure – as stated in the Chef blog post – is that there is always state somewhere in the system and, therefore, the whole system isn’t immutable. That misses the point of immutable components. The main advantage when it comes to state in immutable infrastructure is that it is siloed. The boundaries between layers storing state and the layers that are ephemeral are clearly drawn and no leakage can possibly happen between those layers. There simply is no way to mix state into different components when you can’t expect them to be up and running the next minute.

Atomic Deployments and Validation

Updating an existing server can easily have unintended consequences. That’s why Chef, Puppet, CFEngine or other such tools exist – to take care of consistency across your infrastructure. A central system is necessary to manage the expected state of each server and to take action to ensure compliance. Deployment is not an atomic action but a transition that can go wrong and lead to an unknown state. This becomes very hard and complex to debug, as the exact state you are in is hard to know. Chef, Puppet or CFEngine are very complex systems as they have to deal with an overly complex problem.

Another solution to that problem is to build completely new images and servers that contain the application and the environment every time you want to deploy. In that case, the deployment doesn’t depend on the status the servers were in before, so the result is much more predictable and repeatable. Any third-party issues that may cause the deployment to fail can be caught by validating the new image and ensuring no production system was impacted. This one image can then be used to start any number of servers and switch atomically from the old machines to the new ones by changing the load balancer, for example.

There are of course downsides to rebuilding your images with every deployment. A full rebuild of the system takes a lot longer than simply updating and restarting the application. By layering your deployment you can optimize this, e.g. have a repository to build a base image and use that base image to just put in your application for the deployment image, but it will still be a slower process.

Another problem is that you introduce dependencies to third parties during deployment. If you install packages in the system and your apt repository is slow or down this can fail the deployment. While this could be a problem in a non immutable infrastructure as well you typically interact less with third party systems when you just push new code into an already provisioned system.

By deploying from a pre-provisioned base image and updating that base image regularly you can soften that problem, but it’s still there and might fail a deployment from time to time.

Building the automation currently still takes more time at the beginning of the project, as the tools for building immutable infrastructure are still new or need to be developed. It is definitely more investment in the beginning, but pays off immediately.

You can still use Chef, Puppet, CFEngine or Ansible to build your images, but as they aren’t built for an immutable infrastructure workflow they tend to be more complex than necessary.

Fast Recovery by preserving History

As all deployments are done by building new images, history is preserved automatically for rollback when necessary. The same process and automation that is used to deploy the next version can be used to roll back, which ensures the process of rolling back will work. By automating the creation of the images, you can even recreate historical images and branch off from earlier points in the history of the infrastructure.

Data schema changes are a potential problem, but that’s a general issue with rollbacks. Backwards compatibility and zero downtime deployments are a way to make sure this will work regardless of the changes.

Simple Experimentation

As you control the whole environment and application, any experiments with new versions of the language, operating system or dependencies are easy. With strict testing and validation in place, and the ability to roll-back if necessary, all the fear of upgrading any dependency is removed. Experimentation becomes an integral and trivial part of building your infrastructure.

Makes you collect your logs and metrics in a central location

With immutable components in place, it’s easy to simply kill a misbehaving server. While often errors are simply a product of the environment, for example a third party system misbehaving, and can be ignored, some will keep coming up. Not having access into the servers puts the right incentive on the team to collect and store logs and system metrics externally. This way, debugging can happen while the server is long gone.

If logs and metrics are missing to properly debug an issue, it’s easy to add more data collection to the infrastructure and replace all existing servers. Then once the error comes up again you can debug it fully from the data stored on an external system.

Conclusions

Immutable components as part of your infrastructure are a way to reduce inconsistency in your infrastructure and improve the trust into your deployment process. Atomic deployments, combined with validation of the image and easy rollback, make managing your infrastructure a lot easier.

It forces teams to silo data and expect failures that are inherent when building on top of a cloud infrastructure or when building systems in general. This increases resilience and trains you in a process to withstand any problems, especially in an automated fashion. Furthermore, it helps with building simple and independent components that are easy to deploy and scale.

And it’s not a theoretical idea. At Codeship, we’ve built our infrastructure this way for a long time. Heroku and other PaaS providers are built as immutable components and lots of companies – small and very large – have used immutability as a core concept of their infrastructure.

Tools like Packer have made building immutable components very easy. Together with existing cloud infrastructure they are a powerful concept to help you build better and safer infrastructure. Let me know in the comments if you have any questions or interesting insights to share.

Thanks

I got great feedback by the following people on this article. Thanks for taking the time and helping me to make it much clearer and simply better.

Links

Read the original blog entry...

More Stories By Manuel Weiss

I am the cofounder of Codeship – a hosted Continuous Integration and Deployment platform for web applications. On the Codeship blog we love to write about Software Testing, Continuos Integration and Deployment. Also check out our weekly screencast series 'Testing Tuesday'!

@ThingsExpo Stories
As cloud adoption continues to transform business, today’s global enterprises are challenged with managing a growing amount of information living outside of the data center. The rapid adoption of IoT and increasingly mobile workforce are exacerbating the problem. Ensuring secure data sharing and efficient backup poses capacity and bandwidth considerations as well as policy and regulatory compliance issues.
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.
Although it has gained significant traction in the consumer space, IoT is still in the early stages of adoption in enterprises environments. However, many companies are working on initiatives like Industry 4.0 that includes IoT as one of the key disruptive technologies expected to reshape businesses of tomorrow. The key challenges will be availability, robustness and reliability of networks that connect devices in a business environment. Software Defined Wide Area Network (SD-WAN) is expected to...
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 Pulzze Systems will exhibit at the 19th International Cloud Expo, which will take place on November 1–3, 2016, at the Santa Clara Convention Center in Santa Clara, CA. Pulzze Systems, Inc. provides infrastructure products for the Internet of Things to enable any connected device and system to carry out matched operations without programming. For more information, visit http://www.pulzzesystems.com.
Developing software for the Internet of Things (IoT) comes with its own set of challenges. Security, privacy, and unified standards are a few key issues. In addition, each IoT product is comprised of (at least) three separate application components: the software embedded in the device, the back-end service, and the mobile application for the end user’s controls. Each component is developed by a different team, using different technologies and practices, and deployed to a different stack/target –...
SYS-CON Events announced today Telecom Reseller has been named “Media 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. Telecom Reseller reports on Unified Communications, UCaaS, BPaaS for enterprise and SMBs. They report extensively on both customer premises based solutions such as IP-PBX as well as cloud based and hosted platforms.
Almost two-thirds of companies either have or soon will have IoT as the backbone of their business in 2016. However, IoT is far more complex than most firms expected. How can you not get trapped in the pitfalls? In his session at @ThingsExpo, Tony Shan, a renowned visionary and thought leader, will introduce a holistic method of IoTification, which is the process of IoTifying the existing technology and business models to adopt and leverage IoT. He will drill down to the components in this fra...
Pulzze Systems was happy to participate in such a premier event and thankful to be receiving the winning investment and global network support from G-Startup Worldwide. It is an exciting time for Pulzze to showcase the effectiveness of innovative technologies and enable them to make the world smarter and better. The reputable contest is held to identify promising startups around the globe that are assured to change the world through their innovative products and disruptive technologies. There w...
There is growing need for data-driven applications and the need for digital platforms to build these apps. In his session at 19th Cloud Expo, Muddu Sudhakar, VP and GM of Security & IoT at Splunk, will cover different PaaS solutions and Big Data platforms that are available to build applications. In addition, AI and machine learning are creating new requirements that developers need in the building of next-gen apps. The next-generation digital platforms have some of the past platform needs a...
With so much going on in this space you could be forgiven for thinking you were always working with yesterday’s technologies. So much change, so quickly. What do you do if you have to build a solution from the ground up that is expected to live in the field for at least 5-10 years? This is the challenge we faced when we looked to refresh our existing 10-year-old custom hardware stack to measure the fullness of trash cans and compactors.
The emerging Internet of Everything creates tremendous new opportunities for customer engagement and business model innovation. However, enterprises must overcome a number of critical challenges to bring these new solutions to market. In his session at @ThingsExpo, Michael Martin, CTO/CIO at nfrastructure, outlined these key challenges and recommended approaches for overcoming them to achieve speed and agility in the design, development and implementation of Internet of Everything solutions wi...
Today we can collect lots and lots of performance data. We build beautiful dashboards and even have fancy query languages to access and transform the data. Still performance data is a secret language only a couple of people understand. The more business becomes digital the more stakeholders are interested in this data including how it relates to business. Some of these people have never used a monitoring tool before. They have a question on their mind like “How is my application doing” but no id...
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....
Smart Cities are here to stay, but for their promise to be delivered, the data they produce must not be put in new siloes. In his session at @ThingsExpo, Mathias Herberts, Co-founder and CTO of Cityzen Data, will deep dive into best practices that will ensure a successful smart city journey.
Identity is in everything and customers are looking to their providers to ensure the security of their identities, transactions and data. With the increased reliance on cloud-based services, service providers must build security and trust into their offerings, adding value to customers and improving the user experience. Making identity, security and privacy easy for customers provides a unique advantage over the competition.
SYS-CON Events announced today that 910Telecom will exhibit at the 19th International Cloud Expo, which will take place on November 1–3, 2016, at the Santa Clara Convention Center in Santa Clara, CA. Housed in the classic Denver Gas & Electric Building, 910 15th St., 910Telecom is a carrier-neutral telecom hotel located in the heart of Denver. Adjacent to CenturyLink, AT&T, and Denver Main, 910Telecom offers connectivity to all major carriers, Internet service providers, Internet backbones and ...
Internet of @ThingsExpo, taking place November 1-3, 2016, at the Santa Clara Convention Center in Santa Clara, CA, is co-located with 19th Cloud Expo and will feature technical sessions from a rock star conference faculty and the leading industry players in the world. The Internet of Things (IoT) is the most profound change in personal and enterprise IT since the creation of the Worldwide Web more than 20 years ago. All major researchers estimate there will be tens of billions devices - comp...
SYS-CON Events announced today that Adobe has been named “Bronze 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. Adobe is changing the world though digital experiences. Adobe helps customers develop and deliver high-impact experiences that differentiate brands, build loyalty, and drive revenue across every screen, including smartphones, computers, tablets and TVs. Adobe content solutions are used daily by millions of co...
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, will discuss the key considerations around quality, volume, timeliness, and pedigree that must be dealt with in order to properly fuel that engine.