In this day and age, the overarching expectation for software development teams is that they develop and release quality products rapidly and frequently. In general, they do so by leveraging short development cycles. The challenge for many organizations is that the expectation for speed and quality is the same, regardless of the complexity of the system being developed.
We can all agree that increased application complexity brings an increased risk for quality issues, along with other deployment challenges. So, how can we limit the effect that system complexity has on both application quality and delivery speed?
Below I will discuss the concerns that arise when delivering frequent changes to complex applications. In addition, I will provide common development practices for managing a complex codebase and preserving quality throughout a CI/CD pipeline.
The challenges of delivering frequent changes to complex applications
Complex applications are characterized by complex functionality, and frequent deployments of applications with complicated features can lead to a variety of challenges. Consider the following:
Complicated features can be challenging to test
Ensuring application quality requires DevOps-minded teams to thoroughly test all features – verifying the application is functioning properly. This can be difficult when testing complex features and especially difficult when frequent modifications are being made to these features in preparation for frequent deployments. Challenges arise with ensuring proper test coverage (proper testing for all individual components, as well as testing how these units of code work in conjunction with one another). In addition, features that require complicated processing can create demands as it relates to test data management.
Efficient release management for complicated apps requires effective source code management techniques
Complex systems often have large and complicated codebases. When they’re being modified and released in short development cycles, these codebases are often being worked on by five to ten (or more) developers at a time. Multiple hands in the cookie jar can create challenges for teams trying to manage their codebases effectively.
Developers may find themselves dealing with challenging merges due to changes that conflict with those from other developers. And, if not managed carefully, this can result in unfulfilled application requirements or even broken functionality.
Fortunately for development teams faced with managing frequent releases of complex systems, there are many processes, frameworks and tools that can assist in simplifying this exercise. Let’s take a look at some best practices for effectively managing the development process in a manner that mitigates the risks associated with deploying complex applications.
Continuous testing to the rescue
Let’s first address the process for testing complicated features within an application. How can a DevOps team ensure that complex systems have proper test coverage to verify functionality? The answer lies in implementing continuous testing throughout your development pipeline. Continuous testing can be defined as end-to-end automated testing throughout the development process; and properly implementing continuous testing involves utilizing several different testing concepts.
Developers should write unit tests for individual components, testing their base functionality. In addition, automated integration tests should be written for each feature to ensure these components function properly in conjunction with one another.
These tests can then be configured to run as part of the continuous integration process within your CI/CD pipeline. In other words, when code is committed, the tests should be executed as part of an automated application build process. If any test fails, then the build fails. This serves to notify the developer of issues with their code at the earliest possible moment in the development process.
Early bug discovery then allows for bugs to be fixed early on in the development process, where they’re less expensive to resolve. This helps to ensure application quality at later points in the development lifecycle, which saves time on the backend of the development process. (This is especially important when dealing with large and complicated applications where any major issue could completely destroy the timeline for release).
Manage your codebase effectively
As mentioned above, large and complex codebases are oftentimes developed by large development teams. And, when a bunch of developers are working on an application at once, there’s bound to be some confusion. Therefore, it’s critical to have a well-defined process for managing the source code for such an application.
There are several accepted practices for managing source code effectively. One such approach is to have all developers work in and commit to a common branch, known as trunk or mainline – this is called trunk-based development. The idea is to eliminate the need for long-running feature branches that result in developers getting out of sync with one another.
With trunk-based development, developers either commit directly to the trunk branch or utilize short-running feature branches for development (frequently merging with trunk). The advantages of this particular development style are fairly straightforward. Trunk-based development helps developers avoid complicated merges that can lead to missing or broken functionality.
Additionally, through the process of merging frequently with the trunk branch, the CI/CD pipeline is constantly being triggered. This results in the source code being tested and validated on a consistent basis, which enables the trunk branch to remain in a state that’s almost always ready for release. Development teams find this strategy particularly advantageous when looking to iterate quickly to get enhancements and bug fixes out the door.
The importance of post-deployment monitoring
Development processes that keep developers in-sync and continuous testing practices within your CI/CD pipeline are huge steps towards ensuring application quality, no matter how complex the application. But, whether deploying frequently or infrequently, it should be considered vital to continue to monitor your release after deploying to production. This monitoring should include performance monitoring (such as slow page load times which could indicate design or scalability flaws within the code) as well as incident monitoring, which leads to data that can be aggregated and contextualized to provide opportunities for continuous improvement within your application.
Continuous improvement to release management and deployment
No matter the complexity of the system, robust end-to-end testing throughout your CI/CD pipeline can help to mitigate risk in a particular release. And, when combined with an effective technique for managing source code (keeping devs in sync with one another), developers are empowered to find and resolve issues within their application earlier than ever before in the development process.
While every organization has some uniqueness within their development process, leveraging these practices can help to allow any application (no matter how complex) to remain in a state that’s almost always ready for deployment – simplifying release management.