What is meant by continuous delivery?

Q: Which is an example of continuous delivery in DevOps?

So, in DevOps, continuous delivery is also called Automated deployment pipeline. This will include few manual testing as well like User acceptance testing which generally will be run by the end user and also few manual approval gates, as the code comes close to the production environment.

What is Continuous Delivery?

Continuous Delivery is the ability to get changes of all types—including new features, configuration changes, bug fixes and experiments—into production, or into the hands of users, safely and quickly in a sustainable way.

Índice Show

What is Continuous Delivery?
Why continuous delivery?
Relationship to DevOps[edit]
Relationship to continuous deployment[edit]
Principles[edit]
Deployment pipeline[edit]
Tools/tool types[edit]
Architecting for continuous delivery[edit]
Implementation and usage[edit]
Benefits and obstacles[edit]
Strategies to overcome adoption challenges[edit]
See also[edit]
Further reading[edit]
References[edit]
What is continuous delivery example?
What does continuous delivery mean in agile?
What is continuous delivery in DevOps?
Which is an example of continuous delivery in DevOps?

Our goal is to make deployments—whether of a large-scale distributed system, a complex production environment, an embedded system, or an app—predictable, routine affairs that can be performed on demand.

We achieve all this by ensuring our code is always in a deployable state, even in the face of teams of thousands of developers making changes on a daily basis. We thus completely eliminate the integration, testing and hardening phases that traditionally followed “dev complete”, as well as code freezes.

Why continuous delivery?

It is often assumed that if we want to deploy software more frequently, we must accept lower levels of stability and reliability in our systems. In fact, peer-reviewed research shows that this is not the case—high performance teams consistently deliver services faster and more reliably than their low performing competition. This is true even in highly regulated domains such as financial services and government. This capability provides an incredible competitive advantage for organizations that are willing to invest the effort to pursue it.

The practices at the heart of continuous delivery help us achieve several important benefits:

Low risk releases. The primary goal of continuous delivery is to make software deployments painless, low-risk events that can be performed at any time, on demand. By applying patterns such as blue-green deployments it is relatively straightforward to achieve zero-downtime deployments that are undetectable to users.
Faster time to market. It’s not uncommon for the integration and test/fix phase of the traditional phased software delivery lifecycle to consume weeks or even months. When teams work together to automate the build and deployment, environment provisioning, and regression testing processes, developers can incorporate integration and regression testing into their daily work and completely remove these phases. We also avoid the large amounts of re-work that plague the phased approach.
Higher quality. When developers have automated tools that discover regressions within minutes, teams are freed to focus their effort on user research and higher level testing activities such as exploratory testing, usability testing, and performance and security testing. By building a deployment pipeline, these activities can be performed continuously throughout the delivery process, ensuring quality is built in to products and services from the beginning.
Lower costs. Any successful software product or service will evolve significantly over the course of its lifetime. By investing in build, test, deployment and environment automation, we substantially reduce the cost of making and delivering incremental changes to software by eliminating many of the fixed costs associated with the release process.
Better products. Continuous delivery makes it economic to work in small batches. This means we can get feedback from users throughout the delivery lifecycle based on working software. Techniques such as A/B testing enable us to take a hypothesis-driven approach to product development whereby we can test ideas with users before building out whole features. This means we can avoid the 2/3 of features we build that deliver zero or negative value to our businesses.
Happier teams. Peer-reviewed research has shown continuous delivery makes releases less painful and reduces team burnout. Furthermore, when we release more frequently, software delivery teams can engage more actively with users, learn which ideas work and which don’t, and see first-hand the outcomes of the work they have done. By removing the low-value painful activities associated with software delivery, we can focus on what we care about most—continuously delighting our users.

If this sounds too good to be true, bear in mind: continuous delivery is not magic. It’s about continuous, daily improvement—the constant discipline of pursuing higher performance by following the heuristic “if it hurts, do it more often, and bring the pain forward.”

Continuous delivery (CD) is a software engineering approach in which teams produce software in short cycles, ensuring that the software can be reliably released at any time and, when releasing the software, without doing so manually.[1][2] It aims at building, testing, and releasing software with greater speed and frequency. The approach helps reduce the cost, time, and risk of delivering changes by allowing for more incremental updates to applications in production. A straightforward and repeatable deployment process is important for continuous delivery.

Continuous delivery contrasts with continuous deployment (also abbreviated CD), a similar approach in which software is also produced in short cycles but through automated deployments rather than manual ones. As such, continuous deployment can be viewed as a more complete form of automation than continuous delivery.[citation needed]

Relationship to DevOps[edit]

Continuous delivery and DevOps are similar in their meanings and are often conflated, but they are two different concepts.[3] DevOps has a broader scope,[4] and centers around 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.[4] 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.[5] Thus, DevOps can be a product of continuous delivery, and CD flows directly into DevOps.

Relationship to continuous deployment[edit]

Continuous delivery is the ability to deliver software that can be deployed at any time through manual releases; this is in contrast to continuous deployment which uses automated deployments.[6] According to Martin Fowler, continuous deployment requires continuous delivery.[7] Academic literature differentiates between the two approaches according to deployment method; manual vs. automated.[2][8]

Principles[edit]

Continuous delivery treats the commonplace notion of a deployment pipeline[9] as a lean Poka-Yoke:[10] a set of validations through which a piece of software must pass on its way to release. Code is compiled if necessary and then packaged by a build server every time a change is committed to a source control repository, then tested by a number of different techniques (possibly including manual testing) before it can be marked as releasable.

Developers used to a long cycle time may need to change their mindset when working in a CD environment. It is important to understand that any code commit may be released to customers at any point. Patterns such as feature toggles can be very useful for committing code early which is not yet ready for use by end users. Using NoSQL can eliminate the step of data migrations and schema changes, often manual steps or exceptions to a continuous delivery workflow.[11] Other useful techniques for developing code in isolation such as code branching are not obsolete in a CD world, but must be adapted to fit the principles of CD - for example, running multiple long-lived code branches can prove impractical, as a releasable artifact must be built early in the CD process from a single code branch if it is to pass through all phases of the pipeline.[clarification needed]

Deployment pipeline[edit]

Continuous delivery is enabled through the deployment pipeline. The purpose of the deployment pipeline has three components: visibility, feedback, and continually deploy.[12]

Visibility – All aspects of the delivery system including building, deploying, testing, and releasing are visible to every member of the team to promote collaboration.
Feedback – Team members learn of problems as soon as possible when they occur so that they are able to fix them as quickly as possible.
Continually deploy – Through a fully automated process, you can deploy and release any version of the software to any environment.

Tools/tool types[edit]

Continuous delivery takes automation from source control all the way through production. There are various tools that help accomplish all or part of this process.[13] These tools are part of the deployment pipeline which includes continuous delivery. The types of tools that execute various parts of the process include: continuous integration, application release automation, build automation, application lifecycle management.[14]

Architecting for continuous delivery[edit]

To practice continuous delivery effectively, software applications have to meet a set of architecturally significant requirements (ASRs) such as deployability, modifiability, and testability.[15] These ASRs require a high priority and cannot be traded off lightly.

Microservices are often used when architecting for continuous delivery.[16] The use of Microservices can increase a software system's deployability and modifiability. The observed deployability improvements include: deployment independence shorter deployment time, simpler deployment procedures, and zero downtime deployment. The observed modifiability improvements include: shorter cycle time for small incremental functional changes, easier technology selection changes, incremental quality attribute changes, and easier language and library upgrades.[16]

Implementation and usage[edit]

The CD book written by Jez Humble and David Farley (2010) popularized the term, however, since its creation the definition has continued to advance and now has a more developed meaning. Companies today are implementing these continuous delivery principles and best practices. The difference in domains, e.g. medical vs. web, is still significant and affects the implementation and usage.[17] Well-known companies that have this approach include Yahoo!,[18] Amazon,[19] Facebook,[20] Google,[21] Paddy Power[1] and Wells Fargo.[22]

Benefits and obstacles[edit]

Several benefits of continuous delivery have been reported.[1][17]

Accelerated Time to Market: CD lets an organization deliver the business value inherent in new software releases to customers more quickly. This capability helps the company stay a step ahead of the competition.
Building the Right Product: Frequent releases let the application development teams obtain user feedback more quickly. This lets them work on only the useful features. If they find that a feature isn't useful, they spend no further effort on it. This helps them build the right product.
Improved Productivity and Efficiency: Significant time savings for developers, testers, operations engineers, etc. through automation.
Reliable Releases: The risks associated with a release have significantly decreased, and the release process has become more reliable. With CD, the deployment process and scripts are tested repeatedly before deployment to production. So, most errors in the deployment process and scripts have already been discovered. With more frequent releases, the number of code changes in each release decreases. This makes finding and fixing any problems that do occur easier, reducing the time in which they have an impact.
Improved Product Quality: The number of open bugs and production incidents has decreased significantly.
Improved Customer Satisfaction: A higher level of customer satisfaction is achieved.

Obstacles have also been investigated.[17]

Customer preferences: Some customers do not want continuous updates to their systems. This is especially true at the critical stages of their operations.
Domain restrictions: In some domains, such as telecom and medical, regulations require extensive testing before new versions are allowed to enter the operations phase.
Lack of test automation: Lack of test automation leads to a lack of developer confidence and can prevent using continuous delivery.
Differences in environments: Different environments used in the development, testing and production can result in undetected issues slipping to the production environment.
Tests needing a human oracle: Not all quality attributes can be verified with automation. These attributes require humans in the loop, slowing down the delivery pipeline.

Eight further adoption challenges were raised and elaborated on by Chen.[6] These challenges are in the areas of organizational structure, processes, tools, infrastructure, legacy systems, architecting for CD, continuous testing of non-functional requirements, and test execution optimization.

Strategies to overcome adoption challenges[edit]

Several strategies to overcome continuous delivery adoption challenges have been reported.[6]

Strategies to Overcome CD Adoption Challenges

Strategy	Description
Selling CD as a painkiller	Identify each stakeholder's pain points that CD can solve, and sell CD as a painkiller to that stakeholder. This strategy helps to achieve buy-in from the wide range of stakeholders that a CD implementation requires.
Dedicated team with multi-disciplinary members	Without a dedicated team, it can be hard to progress because employees are often assigned to work on other value streams. A multi-disciplinary team not only provides the wide range of skills required for CD implementation but also smooths the communication with related teams.
Continuous delivery of continuous delivery	Organize the implementation of CD in a way that delivers value to the company as early as possible, onboarding more projects gradually, in small increments and eventually rolling out CD across the whole organization. This strategy helps justify the investment required by making concrete benefits visible along the way. Visible benefits, in turn, help to achieve the sustained company support and investment required to survive the long and tough journey to CD.
Starting with easy but important applications	When selecting the first few applications to migrate to CD, choose the ones that are easy to migrate but that are important to the business. Being easy to migrate helps to demonstrate the benefits of CD quickly, which can prevent the implementation initiative from being killed. Being important to the business helps to secure the required resources, demonstrates clear and unarguable value, and raises the visibility of CD in the organization.
Visual CD pipeline skeleton	Give a team a visual CD pipeline skeleton that has the full CD pipeline view but with empty stages for those they cannot implement yet. This helps to build up a CD mindset and maintain the momentum for CD adoption. The pipeline skeleton is especially useful when the team's migration to CD requires a large effort and mindset changes over a long period of time.
Expert drop	Assign a CD expert to join tough projects as a senior member of the development team. Having the expert on the team helps to build the motivation and momentum to move to CD from inside the team. It also helps to maintain momentum when the migration requires a large effort and a long period of time.

References[edit]

^ a b c Chen, Lianping (2015). "Continuous Delivery: Huge Benefits, but Challenges Too". IEEE Software. 32 (2): 50–54. doi:10.1109/MS.2015.27. S2CID 1241241.
^ a b Shahin, Mojtaba; Ali Babara, Muhammad; Zhu, Liming (2017). "Continuous Integration, Delivery and Deployment: A Systematic Review on Approaches, Tools, Challenges and Practices". IEEE Access. 5: 3909–3943. arXiv:1703.07019. Bibcode:2017arXiv170307019S. doi:10.1109/ACCESS.2017.2685629. S2CID 11638909.
^ Hammond, Jeffrey (9 September 2011). "The Relationship between DevOps and Continuous Delivery". Forrester Research. Forester.
^ a b 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.
^ Swartout, Paul (2012). Continuous Delivery and DevOps: A Quickstart guide. Packt Publishing. ISBN 978-1849693684.
^ a b c Chen, Lianping (2017). "Continuous Delivery: Overcoming adoption challenges". Journal of Systems and Software. 128: 72–86. doi:10.1016/j.jss.2017.02.013.
^ "bliki: ContinuousDelivery". martinfowler.com. Retrieved 2015-10-29.
^ Shahin, Mojtaba; Babar, Muhammad Ali; Zahedi, Mansooreh; Zhu, Liming (2017). "Beyond Continuous Delivery: An Empirical Investigation of Continuous Deployment Challenges". 2017 ACM/IEEE International Symposium on Empirical Software Engineering and Measurement (ESEM). pp. 111–120. doi:10.1109/ESEM.2017.18. ISBN 978-1-5090-4039-1. S2CID 3479812.
^ Humble, J.; Read, C.; North, D. (2006). "The Deployment Production Line". Agile 2006 (Agile'06). pp. 113–118. doi:10.1109/AGILE.2006.53. ISBN 0-7695-2562-8. S2CID 16572138.
^ Fitzgerald, Brian (2014-06-03). Continuous Software Engineering and Beyond: Trends and Challenges (PDF). 1st International Workshop on Rapid Continuous Software Engineering. New York, NY: Association for Computing Machinery. pp. 1–9. doi:10.1145/2593812.2593813. hdl:10344/3896. ISBN 978-1-4503-2856-2. Archived from the original (PDF) on 2014-10-25. Retrieved 2014-10-24.
^ Kluge, Lars (12 September 2013). "Continuous Deployment with MongoDB at Kitchensurfing". slideshare.net. Retrieved 3 January 2014.
^ Duvall, Paul (2012). "Continuous Delivery: Patterns and Anti-Patterns in Software Lifecycle" (PDF). Refcardz. Retrieved October 9, 2015.
^ Phillips, Andrew (29 July 2014). "The Continuous Delivery Pipeline – What it is and Why it's so important in Developing Software". DevOps.com. Archived from the original on 28 September 2015. Retrieved October 9, 2015.
^ Binstock, Andrew (16 September 2014). "Continuous Delivery: The Agile SUccessor". Dr. Dobb's the World of Software Development. San Francisco: UBM.
^ Chen, Lianping (2015). Towards Architecting for Continuous Delivery. The 12th Working IEEE/IFIP Conference on Software Architecture(WICSA 2015). Montréal, Canada: IEEE. doi:10.1109/WICSA.2015.23.
^ a b Chen, Lianping (2018). Microservices: Architecting for Continuous Delivery and DevOps. The IEEE International Conference on Software Architecture (ICSA 2018). IEEE.
^ a b c Leppänen, M.; Mäkinen, S.; Pagels, M.; Eloranta, V. P.; Itkonen, J.; Mäntylä, M. V.; Männistö, T. (2015-03-01). "The Highways and Country Roads to Continuous Deployment". IEEE Software. 32 (2): 64–72. doi:10.1109/MS.2015.50. ISSN 0740-7459. S2CID 18719684.
^ "Implementing Continuous Delivery at Yahoo!". confreaks.tv. 23 October 2013.
^ "Velocity 2011: Jon Jenkins, "Velocity Culture"". youtube.com. 20 June 2011.
^ "Rapid Release At Massive Scale". 2017-08-31.
^ Humble, Jez (13 February 2014). "The Case for Continuous Delivery". thoughtworks.com. Retrieved 16 July 2014.
^ jFrog (December 2014). "2014-year-continuous-integration-revolution".

What is continuous delivery example?

It typically includes automation of additional steps in releasing new software to minimize the manual processes required. For example, a continuous deployment pipeline may automatically release the development team's changes from the repository to the production environment, where customers can use it.

What does continuous delivery mean in agile?

Continuous Delivery Explained After all, according to Agile signatory (and full-time legend) Martin Fowler, Continuous Delivery is “a software development discipline where you build software in such a way that it can be released at any time.”

What is continuous delivery in DevOps?

Continuous delivery (CD) is the process of automating build, test, configuration, and deployment from a build to a production environment. A release pipeline can create multiple testing or staging environments to automate infrastructure creation and deploy new builds.

Which is an example of continuous delivery in DevOps?

So, in DevOps, continuous delivery is also called 'Automated deployment pipeline'. This will include few manual testing as well like 'User acceptance testing' which generally will be run by the end user and also few manual approval gates, as the code comes close to the production environment.