A release channel is a mechanism that software developers and organizations use to manage the delivery of different versions of their software to different groups of users, typically based on the stability, features, and updates of the software. Release channels help control the flow of updates and ensure that different users or environments get the appropriate version of the software based on their needs and at a suitable cadence for them.
Release channels usually correspond to different stages of development, testing, and stability. The question is, how do we know what Release Channel is best for our environment?
The main characteristics of a Release Channel that we need to evaluate for that decision are:
Stability
Each release channel provides a different level of stability. The Stability of a channel is key to understand to determine which channel is suitable for a production or a testing/development environment. Typically:- Stable Channels are designed for production environments, where the main goal is to provide reliability and minimal risk
- Channels like Beta, Edge or Canary provide early access to new features but are much more prone to bugs or instability
Frequency of Updates
Each release channel defines how often new updates are available. For example:- Nightly channels update frequently (even daily), providing access to the latest changes as soon as they are made.
- Stable or LTS channels update much less frequently or only when necessary, like for bug fixes or security patches.
For example, in Mulesoft:
- The Edge channel provides a minor release every 4 months (February, June and October). That’s the faster channel and the one that provides the latest features in the runtime
- The LTS channel releases a new version once a year
Feature Access
Different release channels provide access to different stages of feature development.- Edge/Canary/Alpha channels often get features in their earliest stages, which may still be experimental.
- Stable channels only get features after they’ve passed multiple levels of testing and verification.
Risk Tolerance
Risk tolerance is another key characteristic to understand what release channel better suits our profile.- Stable or LTS channels are designed for users who need a low-risk environment and prioritize reliability over accessing the latest features. More for production environments.
- Beta channels are for users willing to take on more risk (such as encountering bugs or incomplete features) in exchange for early access to new functionality. More for testing or development environments in which we experiment with new features in our app to see if they’ll break our code.
Audience
Each release channel typically targets a specific group of users or profile of users.- Stable/LTS channels target companies requiring production-ready software
- Beta channels target early adopters, testers or Mule developers interested to see new features in action and provide feedback before the release is Generally Available.
- Canary/Nightly channels target developers or highly technical users who are comfortable with instability and want the latest updates as soon as possible.
- Edge channel is more for Cloudhub customers, where they don’t have to worry about rolling out the updates or rolling back if anything goes wrong. All of that is managed by Mulesoft, and this way Cloudhub customers can have a more frequent cadence of new releases without compromising stability
- LTS channel is more for customers on Standalone runtimes or Runtime Fabric, where they are the owners of the infrastructure and the ones responsible of the whole upgrade process. Some companies are not fully equipped to keep up a cadence of upgrading their apps every 4 months (as in the Edge channel) and they prefer to do that once every 12-18 months.
Support and Maintenance
As we’ve seen in this post, not all channels provide the same level of stability, reliability or risk. For that reason, different channels provide different support models, in terms of support periods, bug fixes and security updates availability.- LTS (Long-Term Support) channels provide extended maintenance, offering bug fixes and security updates over several months/years, without introducing new features.
- Edge or Beta channels may offer shorter support periods, with updates being superseded quickly by newer versions.
- The Edge channel provides 5 months of Standard Support and 3 months of Extended Support
- The LTS channel provides 18 months of Standard Support and 6 months of Extended Support
Backwards Compatibility
Channels can differ in how strictly they maintain backward compatibility:- Stable and LTS channels typically emphasize backward compatibility, ensuring that upgrading to a new version won’t break existing systems.
- Edge/Canary channels may introduce changes that are not backward-compatible, requiring users to adjust or update their systems accordingly.
Testing and Validation
Another way to evaluate a release channel is to understand the level of testing and validation of the new versions introduced in the channel. Normally, more stable channels undergo more thorough testing.- Stable and LTS channels receive extensive validation, including unit tests, integration tests, and real-world testing.
- Alpha channels may have only undergone basic or developer-level testing, meaning they can contain bugs or incomplete features.
- Early release channels allow developers to gather feedback from users for future refinement.
Release Cycle
Different release channels follow distinct release cycles:- Stable/LTS channels follow a more conservative, slower release cycle to ensure all features are fully tested.
- Beta/Canary channels have a faster release cycle, pushing updates more quickly for testing or early access purposes.
Rollback Options
Last but not least, it’s very important to understand how easy/available is the rollback mechanism provided by a release channel.- Stable/LTS channels normally provide reliable and well-defined rollback mechanisms so that we can have assurance we can get back to a stable state in a timely fashion if anything goes wrong during the update
- Canary channels are less stable and is usually more complicated to roll back a version. That’s because the main goal of this type of channels is to provide new features as fast as possible and not to invest too many resources in rollback mechanisms.
Examples of Release Channels in the Software Industry
Stable Channel
- Purpose: Provides the most reliable and thoroughly tested version of the software.
- Audience: This is for the general public or users who prioritize stability and need a version that has passed extensive testing.
- Frequency of Updates: Less frequent than other channels, as it only receives updates after they've been tested in other channels.
Beta Channel
- Purpose: Allows users to test features that are nearly complete but may still contain minor bugs or stability issues.
- Audience: For users who want early access to new features and are willing to deal with some instability in exchange for being ahead of the stable release.
- Frequency of Updates: Updates are more frequent than in the stable channel, and users get to experience the latest features before the general public.
Alpha Channel
- Purpose: This is for early-stage testing where features are still being developed, and the software might be unstable or incomplete.
- Audience: Typically used by developers or testers who are deeply involved in the software's development process and are comfortable with bugs, crashes, and incomplete features.
- Frequency of Updates: Very frequent, with the possibility of breaking changes. Updates may be daily or even more frequent.
Canary Channel
- Purpose: Provides the absolute latest code and features but is the most unstable. Changes in the Canary channel are often experimental and could break at any time.
- Audience: Developers or cutting-edge users who want the earliest access to new features and are comfortable with highly unstable software.
- Frequency of Updates: Daily or even multiple times a day, as features are immediately tested after being committed by developers.
Long-Term Support Channel
- Purpose: Delivers versions that are supported for an extended period, receiving critical bug fixes and security patches without introducing new features or changes that might cause instability.
- Audience: Organizations or users who require long-term stability without the need for frequent updates or new features.
- Frequency of Updates: Rare, only when critical patches or security updates are needed.
Nightly Channel
- Purpose: Delivers the latest builds of the software generated from the code repository every night. These builds are experimental and mainly for testing.
- Audience: Developers and contributors who want to see the daily progress of the project.
- Frequency of Updates: Nightly or daily updates.
In summary, release channels are essential tools for balancing the need for stability with the need for innovation, allowing software providers like Mulesoft to roll out updates and features at a pace that meets the needs of different customers.