|Software development process|
|Paradigms and models|
|Methodologies and frameworks|
|Standards and BOKs|
DevOps (a clipped compound of development and operations) is a culture, movement or practice that emphasizes the collaboration and communication of both software developers and other information-technology (IT) professionals while automating the process of software delivery and infrastructure changes. It aims at establishing a culture and environment where building, testing, and releasing software, can happen rapidly, frequently, and more reliably.
- 1 Overview
- 2 History of the term "DevOps"
- 3 DevOps Toolchain
- 4 Relationship to agile and continuous delivery
- 5 Goals
- 6 Cultural change
- 7 Deployment
- 8 Scope of adoption
- 9 References
- 10 Further reading
In traditional, functionally separated organizations there is rarely cross-departmental integration of these functions with IT operations. DevOps promotes a set of processes and methods for thinking about communication and collaboration between development, QA, and IT operations.
History of the term "DevOps"
At the Agile 2008 conference, Andrew Clay Shafer and Patrick Debois discussed "Agile Infrastructure". The term "DevOps" was popularized through a series of devopsdays starting in 2009 in Belgium. Since then, there have been devopsdays conferences held in many countries worldwide.
Because DevOps is a cultural shift and collaboration between development and operations, there is no single DevOps tool, rather a set or “toolchain” consisting of multiple tools. Generally, DevOps tools fit into one or more of these categories, which is reflective of the software development and delivery process:
- Code – Code Development and Review, continuous integration tools
- Build – Version control tools, code merging, Build status
- Test – Test and results determine performance
- Package – Artifact repository, Application pre-deployment staging
- Release – Change management, Release approvals, release automation
- Configure – Infrastructure configuration and management, Infrastructure as Code tools
- Monitor – Applications performance monitoring, End user experience
Though there are many tools available in the market, certain categories of them are essential in the DevOps toolchain setup for use in a company. Some attempts to identify those basic tools can be found in the existing literature.
Tools such as Docker (containerization), Jenkins (continuous Integration), Puppet (Infrastructure as Code) and Vagrant (virtualization platform) among many others are often used and frequently referenced in DevOps tooling discussions.
Relationship to agile and continuous delivery
Organizations that have adopted agile software development are seeing increasing quantities of releases. DevOps was essentially born from this increasing popularity of agile development. Agile and DevOps are similar, but differ in a few important respects. Agile represents a change in thinking, whereas DevOps actually implements organizational cultural change. One goal of DevOps is to establish an environment where releasing more reliable applications faster and more frequently can occur. Release managers are beginning to utilize tools such as application release automation and continuous integration tools to help advance this goal, doing so through the continuous delivery approach.
Continuous delivery and DevOps are similar in their meanings and are often conflated, but they are two different concepts. DevOps has a broader scope, and centers around the cultural change, specifically the collaboration of the various teams involved in software delivery (developers, operations, quality assurance, management, etc.), as well as automating the processes in software delivery. Continuous Delivery, on the other hand, is an approach to automate the delivery aspect, and focuses on bringing together different processes and executing them more quickly and more frequently. They have common end goals and are often used in conjunction to achieve them. DevOps and Continuous Delivery share a background in agile methods and lean thinking: small and quick changes with focused value to the end customer. They are well communicated and collaborated internally, thus helping achieve quick time to market, with reduced risk.
The specific goals of DevOps span the entire delivery pipeline. They include improved deployment frequency, which can lead to faster time to market, lower failure rate of new releases, shortened lead time between fixes, and faster mean time to recovery in the event of a new release crashing or otherwise disabling the current system. Simple processes become increasingly programmable and dynamic, using a DevOps approach. DevOps aims to maximize the predictability, efficiency, security, and maintainability of operational processes. Very often, automation supports this objective.
DevOps integration targets product delivery, continuous testing, quality testing, feature development, and maintenance releases in order to improve reliability and security and provide faster development and deployment cycles. Many of the ideas (and people) involved in DevOps came from the enterprise systems management and agile software development movements.
DevOps aids in software application release management for an organization by standardizing development environments. Events can be more easily tracked as well as resolving documented process control and granular reporting issues. The DevOps approach grants developers more control of the environment, giving infrastructure more application-centric understanding.
DevOps is more than just a tool or a process change; it inherently requires an organizational culture shift. This cultural change is especially difficult because of the conflicting nature of departmental roles. Operations seeks organizational stability; developers seek change; and testers seek risk reduction. Getting these groups to work cohesively is a critical challenge in enterprise DevOps adoption.
Building a DevOps culture
DevOps principles demand strong interdepartmental communication, and team-building and other employee engagement activities are often used to create an environment that fosters this communication and cultural change within an organization. Team-building activities can include board games, trust activities, and employee engagement seminars.
Companies with very frequent releases may require a DevOps awareness or orientation program. For example, the company that operates the image hosting website Flickr developed a DevOps approach to support a business requirement of ten deployments per day; this daily deployment cycle would be much higher at organizations producing multi-focus or multi-function applications. This is referred to as continuous deployment or continuous delivery  and has been associated with the lean startup methodology. Working groups, professional associations and blogs have formed on the topic since 2009.
Scope of adoption
Some articles in the DevOps literature assume, or recommend, significant participation in DevOps initiatives from outside an organization's IT Department, e.g.: "DevOps is just the Agile principle taken to the full enterprise." An example of such broader participation is this recommended change to internal funding processes: "Funding is typically provided in a waterfall manner, with specific hard dates (months, quarters, fiscal year) and gates, not suitable for a Continuous Delivery model. Funding too should be continuous."
Adoption of DevOps is being driven by many factors including:
- Use of agile and other development processes and methods
- Demand for an increased rate of production releases from application and business unit stakeholders
- Wide availability of virtualized and cloud infrastructure from internal and external providers
- Increased usage of data center automation and configuration management tools
- Increased focus on test automation and continuous integration methods
- A critical mass of publicly available best practices
The Theory of Constraints applies to the adaptation of DevOps – the single constraint is the inherent aversion to change from departments within the enterprise. Incremental adoption embodies the methodology the Theory of Constraints provides for combating any constraint, known as “The five focusing steps”.
The Incremental approach centers around the idea of minimizing risk and cost of a DevOps Adoption whilst building the necessary in-house skillset and momentum needed to have widespread – successful implementation across the enterprise. Gene Kim’s Three Ways Principles essentially establishes different ways of incremental DevOps adoption.
The First Way: Systems Thinking
The emphasis is on the performance of the entire system, as opposed to the performance of a specific or single department or individual. Focus is also on all business value streams that are enabled by IT. This process works in a linear fashion ensuring that defects are never passed along.
The Second Way: Amplify Feedback Loops
The emphasis is on increasing feedback and understanding of all teams involved. The outcomes of this will be increased communication and responding to all customers, internal and external, shortening and amplifying all feedback loops, and embedding knowledge where and to whom it’s needed.
The Third Way: Culture of Continual Experimentation and Learning
Two things are equally important: experimentation and practice. Embedding this in the working culture - where learning from taking risks, and repetition and practice are encouraged - is key to mastery. Risk taking and experimentation promote improvement, whilst mastery provides the skills required to revert any mistakes.
- Loukides, Mike (2012-06-07). "What is DevOps?".
- Floris, Erich; Chintan, Amrit; Maya, Daneva (2014-12-10). "A Mapping Study on Cooperation between Information System Development and Operations".
- Samovskiy, Dmitriy (2010-03-02). "The Rise of DevOps". Fubaredness Is Contagious.
- Kim, Gene. "DevOps Culture Part 1".
- Lyman, Jay. "DevOps mixing dev, ops, agile, cloud, open source and business". 451 CAOS Theory.
- Turnbull, James (Feb 2010). "What DevOps means to me...". Kartar.
- Debois, Patrick. "Agile 2008 Toronto". Just Enough Documented Information. Retrieved 12 March 2015.
- Debois, Patrick (2009). "DevOpsDays Ghent". DevopsDays. Retrieved 31 March 2011.
- Debois, Patrick. "DevOps Days". DevOps Days. Retrieved 31 March 2011.
- Gartner Market Trends: DevOps – Not a Market, but Tool-Centric Philosophy That supports a Continuous Delivery Value Chain (Report). Gartner. 18 February 2015.
- Edwards, Damon. "Integrating DevOps tools into a Service Delivery Platform". dev2ops.org.
- Seroter, Richard. "Exploring the ENTIRE DevOps Toolchain for (Cloud) Teams". infoq.com.
- Theakanath, Thomas. "DevOps Stack on a Shoestring Budget". devops.com.
- "Stronger DevOps Culture with Puppet and Vagrant". Puppet Labs. Retrieved 2015-10-22.
- Ambler, Scott W. (12 February 2014). "We need more Agile IT Now!". Dr. Dobb’s The world of software Development (San Francisco: UBM).
- Best Practices in Change, Configuration and Release Management (Report). Gartner. 14 July 2010.
- Hammond, Jeffrey (9 September 2011). "The Relationship between DevOps and Continuous Deliver". Forrester Research (Forester).
- Humble, Jez; Farley, David (2011). Continuous Delivery: reliable software releases through build, test, and deployment automation. Pearson Education Inc. ISBN 978-0-321-60191-9.
- "What is DevOps?". NewRelic.com. Retrieved 2014-10-21.
- Nasrat, Paul. "Agile Infrastructure". InfoQ. Retrieved 31 March 2011.
- Emerging Technology Analysis: DevOps a Culture Shift, Not a Technology (Report). Gartner.
- Loukides, Mike (11 June 2012). What is Devops?. Oreilly Media.
- "Gartner IT Glossary – devops". Gartner. Retrieved October 30, 2015.
- Walls, Mandi (15 April 2013). "Building a DevOps Culture". OReilly Media.
- Roach, Patrick. "Dice Breakers: Using DevOps principles and nerdery to reimagine Team building". DevOps.com.
- "10+ Deploys Per Day: Dev and Ops Cooperation at Flickr".
- "SAM SIG: Applied Lean Startup Ideas: Continuous Deployment at kaChing". SVForum.
- Humble, Jez. "Why Enterprises Must Adopt Devops to Enable Continuous Delivery". Cutter IT Journal.
- "Applied Lean Startup Ideas: Continuous Deployment at kaChing".
- "DevOps Days 2009 Conference".
- Edwards, Damon. "DevOps Meetup Recap".
- "DevOps is Agile for the Rest of the Company". DevOps.com.
- "The Art of DevOps". DevOps.com.
- "Virtual Infrastructure products: features comparison". Welcome to IT 2.0: Next Generation IT infrastructures.
- Ellard, Jennifer. "Bringing Order to Chaos through Data Center Automation". Information Management. SourceMedia.
- "Impact of DevOps on Testing". DevOps.com.
- "Theory of Constraints". vorne Industries Inc. Retrieved 13 November 2015.
- Bhargava, Rajat (27 March 2014). "DevOps Adoption – Startups". DevOps.com.
- Bhargava, Rajat (27 March 2014). "DevOps Adoption – Startups". DevOps.com.
- Kim, Gene (22 January 2013). "DevOps distilled, Part 1: The three underlying principles" (PDF). IBM DeveloperWorks.
- "Incremental DevOps" (PDF).
- Kim, Gene. "The Three Ways: The Principles Underpinning DevOps". IT Revolution Press. Retrieved 13 November 2015.
- Hüttermann, Michael (2012). DevOps for Developers. Apress. ISBN 978-1-430-24569-8.
- Davis, Jennifer; Daniels, Katherine (2015). Effective DevOps. O'Reilly. ISBN 978-1-4919-2630-7.
- Kim, Gene. "Reading List for "The Phoenix Project:" The DevOps Novel (Part 1)". IT Revolution.