DevOps: Difference between revisions

DevOps (a clipped compound of "development" and "operations") is a software development and delivery process that emphasizes communication and collaboration between product management, software development, and operations professionals.^[1][2][3] It seeks to automate the process of software integration, testing, deployment, and infrastructure changes by establishing a culture and environment where building, testing, and releasing software can happen rapidly, frequently, and more reliably.^[4][5][6]

History

At the Agile 2008 conference, Andrew Shafer and Patrick Debois presented on "Agile Infrastructure".^[7] The term DevOps was popularized through a series of "devopsdays" starting in 2009 in Belgium.^[8] Since then, there have been devopsdays conferences, held in many countries, worldwide.^[9]

The popularity of DevOps has grown in recent years, inspiring many other tangential initiatives including OpsDev, WinOps, and BizDevOps.^[10][11][12]

DevOps toolchain

As DevOps is a truly cross-functional mode of working, there is no single "DevOps tool": it is rather a set (or "toolchain") of multiple tools.^[13] DevOps tools tend to fit into one or more of these categories, reflective of key aspects of the development and delivery process:^[14][15]

1. Code — code development and review, source code management tools, code merging
2. Build — continuous integration tools, build status
3. Test — continuous testing tools that provide feedback on business risks
4. Package — artifact repository, application pre-deployment staging
5. Release — change management, release approvals, release automation
6. Configure — infrastructure configuration and management, Infrastructure as Code tools
7. Monitor — applications performance monitoring, end–user experience

While there are many tools available, certain categories are essential in a DevOps toolchain; especially continuous integration (e.g. Jenkins) and infrastructure as code (e.g. Puppet).^[16][17]

Relationship to other approaches

Agile

The need for DevOps arose from the increasing success of agile software development, as that led to organizations wanting to release their software faster and more frequently. They sought to overcome the strain this put on their release management processes, by adopting patterns such as application release automation, continuous integration tools, and continuous delivery.^[18]

Continuous delivery

Continuous delivery and DevOps have common goals and are often used in conjunction, but there are subtle differences.^[19][20]

While continuous delivery is focused on automating the processes in software delivery, DevOps also focuses on the organization change to support great collaboration between the many functions involved.^[19]

DevOps and continuous delivery share a background in agile methods and lean thinking: small and quick changes with focused value to the end customer.^[21] They are well communicated and collaborated internally, thus helping achieve quick time to market, with reduced risks.

Site reliability engineering

In 2003, Google developed site reliability engineering, a new approach for releasing new features continuously into large-scale high-availability systems while maintaining high-quality end user experience.^[22] Some aspects of DevOps have taken a similar appraoch.^[23]

Goals

The goals of DevOps span the entire delivery pipeline. They include:

• Improved deployment frequency;
• Faster time to market;
• Lower failure rate of new releases;
• Shortened lead time between fixes;
• 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.^[24] 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.^[25]

DevOps helps software application release management for an organization, by factoring in infrastructure related code as yet another artifact in the software build and release cycle. When you combine the use of a ticket tracking system (e.g. JIRA), version control (e.g. git) and configuration management tool (e.g. Puppet), changes can be more easily processed, tracked and reported on. Developers and Operations have an interest and stake in keeping production up and running, therefore any code related to infrastructure is now considered yet another artifact in the software delivery process.

Views on the benefits claimed for DevOps

Companies that practice DevOps have reported significant benefits, including: significantly shorter time to market, improved customer satisfaction, better product quality, more reliable releases, improved productivity and efficiency, and the increased ability to build the right product by fast experimentation.^[26]

However, a study released in January 2017 by F5 of almost 2,200 IT executives and industry professionals found that only one in five surveyed think DevOps had a strategic impact on their organization despite rise in usage. The same study found that only 17% identified DevOps as key, well below software as a service (42%), big data (41%) and public cloud infrastructure as a service (39%).^[27]

Cultural change

DevOps is more than just a tool or a process change; it inherently requires an organizational culture shift.^[28] This cultural change is especially difficult, because of the conflicting nature of departmental roles:

• Operations — seeks organizational stability
• Developers — seek change
• Testers — seek risk reduction^[29]

Getting these groups to work cohesively is a critical challenge in enterprise DevOps adoption.^[30][31]

While DevOps reflects complex topics, the DevOps community uses analogies to communicate important concepts, much like "The Cathedral and the Bazaar" from the open source community.^[32]

• Cattle & Pets: the paradigm of disposable server infrastructure.
• 10 deployments per day: the story of Flickr adopting DevOps.

Building a DevOps culture

DevOps principles demand strong interdepartmental communication—team-building and other employee engagement activities are often used—to create an environment that fosters this communication and cultural change, within an organization.^[33] Team–building activities can include board games, trust activities, and employee engagement seminars.^[34]

Deployment

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;^[35] this daily deployment cycle would be much higher at organizations producing multi-focus or multi-function applications. This is referred to as continuous deployment^[36] or continuous delivery ^[37] and has been associated with the lean startup methodology.^[38] Working groups, professional associations and blogs have formed on the topic since 2009.^[6][39][40]

DevOps and architecture

To practice DevOps effectively, software applications have to meet a set of architecturally significant requirements (ASRs), such as: deployability, modifiability, testability, and monitorability.^[41] These ASRs require a high priority and cannot be traded off lightly.

Although in principle it is possible to practice DevOps with any architectural style — the microservices architectural style is becoming the standard for building continuously deployed systems. Because the size of each service is small, it allows the architecture of an individual service to emerge through continuous refactoring,^[42] hence reducing the need for a big upfront design^{[citation needed]} and allows for releasing the software early^{[citation needed]} and continuously.

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."^[43]

A survey published in January 2016 by the SaaS cloud-computing company RightScale, DevOps adoption increased from 66 percent in 2015 to 74 percent in 2016. And among larger enterprise organizations, DevOps adoption is even higher — 81 percent.^[44]

Adoption of DevOps is being driven by many factors — including:

1. Use of agile and other development processes and methods;
2. Demand for an increased rate of production releases — from application and business unit stakeholders;
3. Wide availability of virtualized^[45] and cloud infrastructure — from internal and external providers;
4. Increased usage of data center automation^[46] and configuration management tools;
5. Increased focus on test automation^[47] and continuous integration methods;
6. A critical mass of publicly–available best practices.

References

Further reading

• 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.