How to Speed Up Your CI/CD Pipeline
The modern market is an ever-changing, ever-growing, hyper-modernist environment. Every day, thousands of new competitors emerge worldwide, transforming technologies shake up industries, and new paradigms pioneer the way business is conducted.
In these conditions, fast delivery is more important than ever, and clients want their projects to meet the demands of a competitive market that moves at lightning speed. Continuous Integration and Delivery (CI/CD) is a popular methodology aimed precisely at this, automating the development process and creating a constant cycle.
But even in a method designed to speed up the development cycle, there can be its own "bottlenecks," and that's exactly what we'll talk about today. What we can do to optimize our CI/CD pipeline.
Build Only What You Need
It may be tempting to try to push as much as possible into each commit, but building five different modules or services at once often leads to more problems than it's worth.
The right policy is that each commit should be like a good email—short and to the point. Even in projects based on monolithic architecture, you can gain a lot by sticking to one module at a time.
Focus your efforts on what is absolutely necessary, prioritize, and keep it simple. Massive commits often become bottlenecks related to code reviews, QA, and testing. If 99% of the code is perfect but one line is suspicious, the rest of the code may get stuck in the process while the error is fixed.
If this sounds like someone is selling microservices architecture, that's exactly it. Although monolithic approaches have their strengths, generally keeping everything micro and siloed saves a lot of time in the long run.
Avoid Making Too Many Changes at Once
A brief continuation of the previous point. Feature changes are necessary, but at the same time they represent a certain risk. From a software development perspective, every time we change functionality, we risk introducing bugs or causing unforeseen consequences.
From a user perspective, too many changes can confuse the end user, and it becomes harder to evaluate which changes work and which don't if they are all presented at once. Worse, there is a risk that one disliked change can spoil the entire update, as people tend to generalize a bad experience.
As with building new modules, if one feature fails a test, the others have to be postponed while the culprit is found. What's worse, the more changes, the harder it is to find the source of the problem.
It's worth repeating that the best way to avoid this kind of bottleneck is to think small: one change at a time allows for better organization and is easier for the entire team to handle.
Run Tasks in Parallel
CI/CD pipelines, when used correctly, can save a lot of time, but, like a pipe, they can only handle a certain amount of work. Past a certain threshold, the continuous cycle breaks down and a bottleneck forms.
For those not too familiar with software development, in most cases, build stages run sequentially. That is, each step runs independently and only after the previous one is complete.
Sometimes we can break the process into separate steps and run them simultaneously, which is commonly called parallel or concurrent execution. Five tasks, each taking a minute, will take five minutes sequentially, but only one minute in parallel.
Obviously, not all tasks can be run in parallel, nor need they be. Some tasks are quick or efficient enough to handle the load. Other tasks may require more time and resources, and in those cases, the process can be sped up by creating additional instances to work in tandem.
Cache, Cache, Cache
Artifacts from previous CI/CD releases can be reused in new cycles. For example, a package or container required by your application can be used in subsequent cycles.
To avoid having to download or fully rebuild the resource pool for each cycle, you should cache everything and reuse it wherever possible. There are great tools for this, such as Artifactory.
Reusing resources that are already at hand can significantly speed up the CI/CD pipeline. At the same time, it reduces the risk of compatibility issues.
While caches are useful, they are not meant to be used forever. It's important to clear the cache when updating or when it's no longer needed, to avoid confusion later.
Using Canary Releases
Some DevOps teams release preliminary builds to a small subset of users and gather feedback before committing to a full build. Canary releases help gather useful data about changes without exposing the entire user base to potential bugs and issues.
Large development teams can even create multiple canary releases, each targeting different user subsets. This way, different changes can be evaluated in parallel and potential problems can be identified more easily.
For example, if you have three user groups—A, B, and C—and group A reports a bug, you know that something is happening specifically with that canary release. Thus, it's easier to track the source of the problem.
Pipeline Analysis
We saved the most important for last. We cannot emphasize enough how important it is for the team to constantly monitor the CI/CD pipeline. Measure how long each cycle takes, and take a close look at the tasks that take the most time.
Is that time spent on high-value stages? If not, what can be done to reduce overall time or reshuffle steps?
Are there lengthy stages that provide no benefit? Why are they there? Can they be safely removed?
By understanding your own pipeline, you can make better decisions on how to speed up each cycle. Remember, CI/CD pipeline development is an iterative process. You must keep working on it and constantly monitor it to find areas for improvement.