Continuous Delivery vs. Continuous Deployment: Where to draw the line?
You’ve likely heard of the term CI/CD pipeline. You have probably known about these practices: continuous integration, continuous delivery, and continuous deployment as well.
But the uncertainty remains: What are the differences between continuous delivery and continuous deployment? Which one should you apply to your CI/CD pipeline? How are these terms related to one another? How to find out which one suits your team best?
This blog will clear out the confusion, from the definitions to the differences and help you pick out the most appropriate practice for your team.
What is Continuous Delivery?
Continuous delivery is a software engineering practice in which code changes are prepared to be released to production. However, keep in mind that the codes must pass the automated unit testing, integration testing, system testing before being pushed to production.
The transition between continuous integration and continuous delivery is usually completed automatically, including automated testing at the unit, integration, and system levels.
Automated tests provide more thorough validation. Developers can update and locate issues before the release is publically available. Automated testing and an automated release process is a perfect combination to establish a seamless and mechanized pipeline.
With the releases available in the staging environment, continuous delivery allows developers to release at any rate of their choice, within a single push of a button. That means the decision to initiate a release must be made by a human, and only after that does continuous delivery takes place.
What is Continuous Deployment?
Continuous deployment takes a further step from continuous delivery. It is a software engineering practice that ensures code changes are continuously released into the production environment. The goal is to release a new version whenever developers make changes and automatically get those changes to the end users.
Continuous deployment is the ultimate goal of software development companies. Your company’s development and IT teams must properly prepare to tackle implementing continuous deployment. Production-ready environments and appropriate practices must be put in place to make sure the live environment is up to par.
In continuous deployment, codes are run and maintained in a simulated environment, ensuring that the ultimate quality is taken into consideration. Real-time monitoring of the live environment is also a requirement to keep track of any arising issues and resolve them quickly.
Differences between Continuous Delivery and Continuous Deployment
This question is often asked: What is the CD in CI/CD? Does it stand for deployment or delivery?
Well, the answer is both. Depending on the existing workflow and requirements, your team would pick the practice that best fits them and their product.
Continuous delivery is the best choice for companies that want to take control and be the last filter before new releases are deployed to the end users. This practice also allows businesses to operate in a more regulated way: automatically test the final product with automation tools, then have it manually revised by the Quality Assurance (QA) team.
Continuous deployment can be considered a special case of continuous delivery. In this practice, the team must ensure the builds passed all tests and that the test suites are good enough to qualify builds and automatically deploy them.
Both continuous deployment and continuous delivery depend on real-time infrastructure and application monitoring tools to maintain the product and uncover any issues that had not been found before release.
Continuously testing and monitoring the product and incorporating new releases into tests are the ultimate aspect of quality control that any successful product needs.
Continuous Delivery vs. Continuous Deployment | Table Comparison
|Continuous Delivery||A software engineering practice in which code changes are prepared to be released to production.||– Ensures frequent releases.
– Ensures releases are completed in smaller chunks.
– Allows instant responses to defects.
– Makes releases more stable, reliable, and controllable.
|Organizations that want to stage new features and releases on a frequent schedule||– Requires using continuous delivery solutions to automate deployment.
– Test automation is leveraged to identify whether the software meets exit criteria or not.
|Continuous Deployment||A software engineering practice that ensures code changes are continuously released into the production environment.||– Ensures each deployment stage is completed quickly and reliably.
– Eliminate manual steps and automate the entire process.
– Allows teams to create a fully automated CI/CD pipeline.
|Organizations that release new features on a daily and hourly basis. Ensure cross-department coordination (development, support, marketing, business, etc.) is maintained.||– Same as continuous delivery with an added emphasis in testing once in production.
– Ability to automate rollback of production features should also be considered.
Benefits of Each Practice
Continuous delivery ensures that releases are completed on a regular basis in smaller chunks. Even if the end users do not notice the significant changes, releasing on a smaller scale several times a day is often more effective than a giant release on a weekly or even longer timescale.
End users are more receptive to small changes than large ones. These smaller changes are also more stable, reliable, and controllable.
Failed test cases can arise at any level and environment. Therefore, the CI/CD pipeline must include a feedback channel to report failures to developers quickly. These feedback loops must be as short as possible to compete against the steady stream of releases. Developers can then put the failed tests into the backlog to repair at a later sprint — or if the failure is critical, repair right away. Quick responses to critical failures is a key benefit of implementing a CI/CD pipeline into every development lifecycle.
Successful continuous deployment happens when teams rely on an automated infrastructure to ensure each part of the deployment is achieved in a quick and reliable manner. Manual testing is not an option in continuous deployment as it slows down the process. Additionally, it is not as efficient compared to automated testing.
Continuous deployment allows teams to commit to a fully automated pipeline, including deploying to production. By automatically pushing new releases into production, the team will no longer have to worry about “big releases” and receiving feedback directly from the users’ end on the product.
How Continuous Integration, Continuous Deployment, and Continuous Delivery relate to each other
This brings us to the question: What does CD mean in a CI/CD pipeline?
A typical CI/CD pipeline begins with the continuous integration process — allowing developers to integrate code changes into a shared repository continuously.
This ensures code can be continuously tested, that developers are not duplicating efforts from other developers, and that the integration into the code base happens more smoothly.
After the continuous integration phase, the production moves on to continuous delivery. The code changes will go through multiple fixes and feedback before being pushed into a production-like environment.
In continuous delivery, the team decides what and when to deploy new updates to the customers.
The deployment process can take a step further with continuous deployment — completely free of human interference. These two concepts do not share the same definition, yet they have a mutual goal of automating and streamlining the development process.
Sometimes, continuous delivery is combined with continuous deployment to exploit the benefits from both practices to the fullest.
For a more in-depth breakdown of what CI/CD is, be sure to check out our previous blog: What is CI/CD?
Want to Learn More?
Whether it is continuous delivery or continuous deployment that your team integrates into the CI/CD pipeline, both are great practices to ensure your team always stay up to date on releases and keep the customers happy.
From planning to coding, then building out the code implementation, the most important part is to test the pipeline continuously and thoroughly. Then the workflow moves on to release the code to production, deploy the changes to the live environment, operating and monitoring the release to note any elements that should be fixed or upgraded.
Download Katalon Studio for free to help with your CI/CD implementation and test automation requirements.
Further reading: Best 14 CI/CD Tools You Must Know | Updated for 2019Trigger modal