“Software is eating the world” is no longer a hopeful vision. It’s happening. It’s here. Software is driving the world’s most important technological trends, and 2020 will prove to be an inflection point for several of them.
Underlying the rapid pace of software transformation is another trend that has become immensely popular in itself. The rise of continuous delivery has enabled software companies to turn their ideas into reality faster than ever before.
Let’s take a look at this software development practice in more detail and discuss ways you can better implement it on your team.
Continuous delivery means the default state of your software build is “ready for deployment”. Each new update to the source code is automatically tested, built, and configured for deployment. This process makes deployments a predictable and routine affair that can be performed on the drop of a hat. Here’s a great primer video on continuous delivery and its cousins, continuous integration, and continuous deployment.
Before the days of continuous delivery, software releases would cause massive bottlenecks for the application and operation teams. Teams would be so backed up and under immense deadline stress that releases would typically either be delayed or contain a number of errors. For more and more teams, implementing both a DevOps mentality and a continuous delivery strategy, those stressful days are long gone.
Continuous delivery is often confused with continuous deployment, but the two methodologies are distinctively different. If a team subscribes to continuous deployment, every change is sent through the pipeline of testing and is automatically released into production. This results in a number of incremental deployments occurring everyday. With continuous delivery, you have the capability and confidence to automatically release every change, but choose to deploy manually instead.
Continuous delivery was developed with speed in mind. Each new software revision is automatically built, tested, and prepared for deployment, even if you choose not to deploy continuously. You’ll also save time by catching errors before they’re deployed, which we talk about below.
Not only does CD speed up deployment, it actually reduces the risk of bad deployments as well. Errors are much less likely to occur throughout the process, and it becomes much easier to identify errors when they do occur. Using a deployment monitoring tool such as Retrace, you can immediately identify which deployment version caused the error and make the fix.
The best-case scenario is to catch errors before a new version is released. Continuous delivery enables this because the software is constantly in a production-like environment, ready to be deployed. This helps teams avoid last-minute hiccups and stay on schedule.
Continuous delivery leads to more deployments, which means more frequent feedback from the customer. Imagine spending a year on a massive software update, only to have the user completely hate it (or worse, not care at all). CD helps you waste less time by learning quickly if you’re making the changes your customers care about. This is where Agile methodology is also incredibly beneficial.
The terms continuous delivery (CD) and continuous integration (CI) are often interchangeably used. However, there are clear differences between both. Not even speaking about the differences with continuous deployment.
Firstly, continuous integration focuses on merging back changes as often as possible to the main branch. This means the application will be built and tested for every small code increment. It provides developers with fast feedback about the quality of their code. Continuous integration is therefore commonly associated with an agile approach of software development. Next, let’s learn what’s different with continuous delivery.
Continuous delivery acts as a subset of continuous integration. That means it only focuses on delivering software as quickly as possible to the customer. Therefore, continuous delivery focuses on improving the release process. The ultimate goal is to automate the full software delivery process. However, that’s absolutely not the end goal. Many more optimizations are possible such as caching dependencies to speed up the delivery process. For example, you would cache all the dependencies for your product. Only if one of the dependencies changes, you would download and cache this one again.
Lastly, continuous deployment talks about automating the whole software delivery process. What do we want to achieve here? We want to automate each step of the deployment process throughout all stages up to production. This means the continuous deployment process takes care of testing the code for different environments and eventually deploys the application to the production environment. Of course, the process stops if some tests fail for a certain environment. In short, continuous deployment is ideal for shortening the feedback loop to the customer.
The continuous delivery process begins with another popular software development practice: continuous integration. Continuously integration means new code from each developer is merged in real-time, ensuring the new changes will work together in production. We see a lot of customers using tools like Jenkins or Bamboo to streamline the continuous integration and continuous delivery process.
The next step in the CD process is quality checks. Teams will roll out deployments in incremental stages to users who try the new releases and ensure quality control. These “deployment rings” or stages are production-like environments, giving you a look at exactly how your deployments would perform in production.
Many teams will take the “fail fast” approach when it comes to testing. This means the tests that are most likely to fail the quickest are run first, and the longer tests occur only after the “fail fast” tests have been ran successfully. This allows teams to identify quick fixes immediately and then begin working on the next deployment as the longer tests take place.
Monitoring is a critical element of continuous delivery, but manual monitoring can be a difficult and time consuming task. Using a deployment or application monitoring tool allows you to easily keep tabs on your software metrics and KPIs. When you see a red flag pop up, whether it be load times or server utilization, you can quickly identify which release caused the error. From there, simply rollback the latest deployment and send it back to the queue.
Retrace by Stackify provides you with comprehensive deployment tracking to pinpoint how deployments affected your customized metrics. Below is an example of what Retrace deployment tracking looks like in the Dashboard view. The red arrows are pointing to the deployment markers.
If you want to use Stackify’s Retrace dashboard as well, read about the functionalities Stackify offers and why it’s helpful for your engineering team.
Continuous delivery is becoming table stakes for software companies. To put it bluntly, those who don’t adopt a faster, more agile software development process will perish.
Luckily there’s an entire fleet of tools and a community of helpful experts to help you build a more continuous development cycle. So move fast, break (fewer) things, and change the world, one software update at a time.