Today’s software-obsessed world demands accelerated time-to-market, enhanced productivity, seamless IT alignment, and reduced costs. Thankfully, software development teams all over the world have finally woken up to the fact that deploying and delivering software (or parts of it) in a continuous fashion is a far better way to achieve these goals – than delivering it in one go.
DevOps (and its continuous everything concepts) has emerged as the gold standard for enabling a quicker transformation, allowing organizations to absorb new priorities, so they can align themselves to address rapidly changing business requirements. Offering the tools teams need to accelerate high-quality software development, DevOps ensures fewer bugs while allowing changes to be implemented easily and continuously.
But when it comes to knowing the difference between continuous deployment and continuous delivery, there is always a lot of confusion! Read on to understand the real differences between the two concepts that are changing the face of software development.
The realm of continuous deployment and continuous delivery
In the DevOps world, continuous deployment and continuous delivery are often used interchangeably, when in reality, the two are different in many ways. While continuous deployment makes sure that every change that is made to the code in production is released to customers quickly and efficiently, the aim of continuous delivery is to make sure that once the code has been tested, it is automatically released into the production environment.
Let’s look at the two concepts in detail:
Atlassian defines continuous deployment as, “a software release process that uses automated testing to validate if changes to a codebase are correct and stable for immediate autonomous deployment to a production environment”. By making sure all changes are automatically passed through all stages of the production pipeline and released to customers, continuous deployment offers a great way to shorten the feedback loop. Since only a failed test will prevent a new change to be deployed to production, developers can focus on building software and witness changes go live quickly and efficiently.
On the other hand, Atlassian defines continuous delivery as, “an extension of continuous integration that automatically deploys all code changes to a testing and/or production environment after the build stage”. This means, in addition to automated testing, teams can also have an automated release process in place and deploy applications at any time with the simple click of a button. It also allows them to decide the frequency of releases – that suits their business requirements – and enjoy easy and assured deployments into production.
Understanding the differences between them
Continuous deployment and continuous delivery deliver exceptional benefits to the software development process: while one makes the development process faster, the other takes away the complexity. Together, they ensure deployment pipelines are triggered automatically and feedback loops are faster – making iterations quicker and easier.
Here’s how the concepts differ across different parameters:
Goal: The goal of continuous deployment is to automate the process of deployment, so changes can be released quickly. The goal of continuous delivery is to keep code in an easily deployable state, so new features and changes can be quickly and reliably released.
Process: Continuous deployment takes validated features from the staging environment and deploys them into the production environment – whenever they are ready for release. On the other hand, continuous deployment runs a progressive set of test suites against every build, enabling teams to move bug-free software to a production-like environment.
Approvals: In continuous deployment, no approvals are needed since changes are released to production automatically. In continuous delivery, although every change that is pushed to the main repository is ready to be shipped, it still requires human approval.
Human involvement: While continuous deployment requires no human intervention, in continuous delivery, tests have to be performed manually to ensure the release of high-quality, bug-free software and code has to be deployed manually to the production environment.
Benefits: Continuous deployment delivers benefits across faster development, and low-risk releases. Since issues are quickly and easily fixed, it helps reduce lead time while ensuring a continuous stream of improvements. On the other hand, continuous delivery reduces development complexity, enabling teams to always have ready-to-deploy code for reliable and faster releases. Through shorter feedback loops and faster iterations, it also allows for improved product quality – and thus better user satisfaction.
Bringing high-quality software to the market quickly and efficiently requires you to embrace DevOps and the concepts of continuous deployment and delivery. While both these concepts are core to successful DevOps outcomes, if you want to maximize the benefits of continuous deployment and continuous delivery, make sure to automate the build process such that code is compiled, tested and deployed to the production environment as soon as efficiently as possible. At the same time, remember to deploy to production as early as possible, so you can execute a set of test suites against every build and release small batches – to easily troubleshoot and rectify issues.
The above article is authored by Anurag Sinha, Co-Founder & Managing Director, Wissen Technology (Wissen.com)