As engineering teams increasingly adopt DevOps as their software development strategy, they are becoming faster and more efficient. Unfortunately, this speed and efficiency can expose cracks in the delivery system as well as other bottlenecks to productivity. Often you can find information on how to adopt DevOps practices like continuous integration (CI) and continuous deployment, but there isn’t as much information on what could go wrong and how to handle those challenges.
First, let’s note that continuous delivery is different from continuous deployment. Though you may see these terms used interchangeably, they do mean different things. Continuous delivery means that the main codebase is always in a state where it is ready to be deployed. Despite this, it doesn’t mean that there is an actual delivery or release. A manual step is required to deploy the code to production.
On the other hand, continuous deployment involves automating all of the steps necessary to deploy. It is the final stage in the process of software development automation. With continuous deployment, all commits that pass the automated CI tests are deployed to an actual production environment. This requires both CI and continuous delivery.
Why is continuous deployment important?
Traditionally, software development teams were primarily concerned with their release schedules. When there was code developed for new features or existing code in need of fixes, all of the changes would be added to one big release. A specific time would be set for the updates and downtime was often expected while the release was being deployed. With modern software development practices, it is now possible to have frequent and automatic releases and updates. Deploying continuously comes with several benefits:
- Engineering teams can take immediate action in response to changes in the market. They no longer need to wait for a major release to push changes to their codebase.
- You can automate the entire development process from commit to deploy. This means that the system administrators don’t have to perform releases themselves, and it frees up their time to work on their other tasks.
- Engineers no longer get stressed out as the release date approaches. This frees them up to concentrate on feature-driven development and testing.
- It allows for real-world experimentation. Internal and external customers can be a part of the QA process, and you get immediate user feedback as well as the ability to perform A/B testing in a production environment.
The result is that management will be able to see continuous progress and users will get features and hot fixes as soon as they are ready. However, the success of continuous deployment depends on various factors that include the quality of the test suite, deployment strategies, and the adoption of continuous deployment best practices.
Problems associated with continuous deployment
While continuous deployment allows for the benefits listed above, it also exposes several problems that can affect the success of a deployment if a solution is not present. Such problems include:
- A lack of confidence in the pipeline. Developers and managers can lack confidence in the automated deployment fearing that they will push poor quality code. This is due to two main reasons:
- A lack of confidence in the test suite. A fundamental component of continuous deployment is automated testing. Challenges that come with testing include flaky tests, an increase in testing time, and incomplete test coverage.
- A lack of confidence in the security checks and not factoring in security from the onset of the process.
- The use of external resources and OSS helps reduce development time. However, using these resources requires monitoring their status and their security issues.
- The availability of tools, their compatibility, and their configuration. Finding the right combination of tools for testing, security, and automation can be challenging.
- Dealing with multiple teams across a large organization is difficult and synchronization becomes a big problem. The product team and marketing team, for instance, need early alignment to eliminate last-minute revisions that delay deployments.
- Depending on your deployment strategy, needing additional infrastructure leads to additional costs.
So, how do you ensure that your team can achieve zero-downtime deployments?
Handling roadblocks to zero-downtime
Here are some suggestions to reduce or eliminate the problems described above:
- Adopt test-driven development practices to provide exhaustive test coverage for your project.
- Coordinate with the security team early and often.
- Add security scans of your OSS and third-party services.
- Use best-in-class tooling that enables flexibility, compatibility, and functionality.
- Create a visible development schedule for all involved parties and require strict adherence.
- Develop architecture using microservices. This architecture is backward compatible, it isolates changes, and it allows testability within each service.
- Research the best deployment strategy for your project before making infrastructure changes and additions.
Additional continuous deployment best practices
To further enhance zero-downtime deployments, the following best practices should be employed:
- Treat your infrastructure as code. Use version control and testing for changes in infrastructure the same way you would for changes in code.
- Establish a communication channel where alerts can be sent to the relevant team members.
- For every task, whether it be a feature request or a bug fix, use an issue tracker.
- Use a branch-naming convention that contains the issue number.
- Never commit directly to the master branch.
- Build high availability into your infrastructure to provide a redundant and resilient system.
When the challenges associated with continuous deployment are adequately considered, it’s a solution that offers continuous improvement. Immediately responding to changes in the market, automating your entire pipeline from commit to deploy, reducing stress on your engineers, and experimenting in real-world environments allows for delivering more value to your users more often.
Alice Njenga enjoys converting dense technical material into articles that are easy to understand for both the layman and the tech professional.