Jenkins versions and LTS - Deep Dive

Overview - Jenkins versions and LTS

What is it?

Jenkins is a tool that helps automate software building and testing. It has different versions released regularly. Some versions are called Long-Term Support (LTS) versions, which are more stable and updated less often. Other versions are called weekly releases, which have the newest features but may be less stable.

Why it matters

Using the right Jenkins version helps teams avoid unexpected problems during software automation. Without clear versioning and LTS, users might face bugs or instability that slow down their work. LTS versions provide a safe choice for critical projects, while weekly versions let users try new features early.

Where it fits

Before learning about Jenkins versions, you should understand what Jenkins is and how it automates tasks. After this, you can learn about Jenkins plugins and how to manage them, which also depend on version compatibility.

Mental Model

Core Idea

Jenkins versions balance stability and new features by offering Long-Term Support releases for reliability and weekly releases for innovation.

Think of it like...

Think of Jenkins versions like car models: LTS versions are like reliable family cars that get safety updates regularly, while weekly versions are like sports cars with the latest gadgets but sometimes need more tuning.

┌───────────────┐      ┌───────────────┐
│ Weekly Release│─────▶│ New Features  │
│ (Frequent)    │      │ (Less Stable) │
└───────────────┘      └───────────────┘
         │                      ▲
         ▼                      │
┌───────────────┐      ┌───────────────┐
│ LTS Release   │◀────│ Stability &   │
│ (Less Frequent)│     │ Bug Fixes     │
└───────────────┘      └───────────────┘

Build-Up - 7 Steps

1

Foundation

What is Jenkins and its purpose

Concept: Introduce Jenkins as a tool for automating software tasks.

Jenkins is a program that helps developers automatically build, test, and deliver software. Instead of doing these steps by hand, Jenkins runs them for you whenever you want.

Result

You understand Jenkins is an automation tool for software development.

Knowing Jenkins automates repetitive tasks helps you see why managing its versions matters for smooth software delivery.

2

Foundation

Understanding software versioning basics

Concept: Explain what software versions are and why they change.

Software versions are like labels that show updates or changes. New versions can fix problems or add features. Sometimes, versions are released often; other times, they come less frequently but are more stable.

Result

You grasp that software changes over time and versions help track those changes.

Understanding versioning basics prepares you to learn why Jenkins has different types of releases.

3

Intermediate

Difference between Jenkins weekly and LTS versions

🤔Before reading on: do you think weekly Jenkins versions are more stable or less stable than LTS versions? Commit to your answer.

Concept: Introduce the two main Jenkins release types and their purposes.

Jenkins releases two main types of versions: weekly and LTS. Weekly versions come out every week with the latest features but might have bugs. LTS versions come out every few months and focus on stability and bug fixes, making them safer for important projects.

Result

You can tell the difference between Jenkins weekly and LTS versions and when to use each.

Knowing the trade-off between new features and stability helps you choose the right Jenkins version for your needs.

4

Intermediate

How Jenkins LTS versions are created

🤔Before reading on: do you think LTS versions include all weekly features or only selected ones? Commit to your answer.

Concept: Explain the process of selecting features and fixes for LTS releases.

LTS versions are made by picking stable features and bug fixes from weekly releases over a period. They test these carefully to avoid new problems. This means LTS versions don’t always have the newest features but are more reliable.

Result

You understand that LTS versions are curated and tested snapshots of weekly releases.

Understanding how LTS versions are made shows why they are trusted for production environments.

5

Intermediate

Version compatibility with Jenkins plugins

🤔Before reading on: do you think plugins always work with any Jenkins version? Commit to your answer.

Concept: Introduce the importance of matching Jenkins versions with compatible plugins.

Jenkins uses plugins to add features. Plugins are tested to work with certain Jenkins versions. Using a plugin with an incompatible Jenkins version can cause errors or failures.

Result

You realize that choosing the right Jenkins version affects plugin stability.

Knowing version compatibility prevents common errors and downtime in Jenkins setups.

6

Advanced

Managing Jenkins upgrades between versions

🤔Before reading on: do you think upgrading Jenkins is always safe without preparation? Commit to your answer.

Concept: Teach best practices for safely upgrading Jenkins versions, especially from LTS to newer releases.

Upgrading Jenkins requires backing up data and checking plugin compatibility. Jumping from an old LTS to a new weekly version can cause issues. It’s safer to upgrade step-by-step and test in a staging environment first.

Result

You learn how to plan Jenkins upgrades to avoid breaking automation pipelines.

Understanding upgrade risks helps maintain continuous delivery without interruptions.

7

Expert

Surprises in Jenkins versioning and LTS policy

🤔Before reading on: do you think LTS versions always lag behind weekly releases by a fixed time? Commit to your answer.

Concept: Reveal nuanced facts about Jenkins LTS timing and versioning policies that affect real-world use.

Jenkins LTS versions are not fixed to a strict schedule; they depend on the stability of weekly releases. Sometimes LTS versions include backported fixes or skip certain weekly features. Also, plugin developers may target weekly versions first, causing delays in LTS support.

Result

You gain insight into the flexible and complex nature of Jenkins versioning and LTS releases.

Knowing these nuances helps you anticipate versioning challenges and plan Jenkins maintenance better.

Under the Hood

Jenkins versions are built from source code repositories. Weekly releases are automated builds from the latest code, including new features and fixes. LTS versions are created by selecting stable commits from weekly releases, then running extensive tests and quality checks before packaging. This process ensures LTS versions have fewer bugs and more predictable behavior.

Why designed this way?

Jenkins needed a way to serve both users who want the latest features and those who need stability. Weekly releases provide rapid innovation, while LTS versions reduce risk for production systems. This dual approach balances progress with reliability, avoiding forcing all users into unstable versions or slow updates.

┌───────────────┐
│ Jenkins Code  │
│ Repository    │
└──────┬────────┘
       │
       ▼
┌───────────────┐      ┌───────────────┐
│ Weekly Builds │─────▶│ New Features  │
│ (Automated)   │      │ & Fixes       │
└──────┬────────┘      └───────────────┘
       │
       ▼
┌───────────────┐
│ LTS Selection │
│ & Testing     │
└──────┬────────┘
       │
       ▼
┌───────────────┐
│ LTS Release   │
│ (Stable)      │
└───────────────┘

Myth Busters - 4 Common Misconceptions

Quick: Do you think Jenkins LTS versions always have the newest features? Commit yes or no.

Common Belief: LTS versions always include the latest features from weekly releases.

Reality: LTS versions only include features that have been tested and deemed stable, so they often lag behind weekly releases.

Why it matters: Assuming LTS has the newest features can lead to missing important updates or trying to use features that aren’t available, causing confusion.

Quick: Do you think you can safely upgrade Jenkins from any version to the latest without testing? Commit yes or no.

Common Belief: Upgrading Jenkins to the latest version is always safe and straightforward.

Reality: Upgrading without testing can break plugins or automation because of incompatibilities or changes in Jenkins internals.

Why it matters: Ignoring upgrade risks can cause downtime and lost productivity in critical automation pipelines.

Quick: Do you think Jenkins plugins work with all Jenkins versions? Commit yes or no.

Common Belief: Plugins are universally compatible with all Jenkins versions.

Reality: Plugins specify compatible Jenkins versions; using them outside this range can cause failures.

Why it matters: Misunderstanding plugin compatibility leads to errors and unstable Jenkins environments.

Quick: Do you think Jenkins LTS versions are released on a fixed schedule every few months? Commit yes or no.

Common Belief: Jenkins LTS versions are released on a strict, fixed schedule.

Reality: LTS releases depend on the stability of weekly releases and can vary in timing; they are not strictly scheduled.

Why it matters: Expecting fixed schedules can cause planning mistakes and surprises in maintenance windows.

Expert Zone

1

LTS versions sometimes backport critical fixes from newer weekly releases without including all features, creating hybrid stability.

2

Plugin developers often release updates targeting weekly versions first, causing a delay before full LTS compatibility.

3

The Jenkins community uses a voting system to decide when a weekly release is stable enough to become an LTS, reflecting community-driven quality control.

When NOT to use

Avoid using weekly Jenkins versions in production environments where stability is critical; instead, use LTS. For experimental features or plugin development, weekly versions are better. If you need guaranteed plugin compatibility, check plugin documentation before upgrading.

Production Patterns

Many organizations run Jenkins LTS in production for reliability and schedule upgrades during maintenance windows. They test upgrades in staging environments with the same plugin set. Some use weekly versions in development or testing to try new features early before promoting to LTS.

Connections

Semantic Versioning

Builds-on

Understanding Jenkins versioning is easier when you know semantic versioning principles, which help communicate changes and compatibility.

Software Release Life Cycle

Same pattern

Jenkins versions follow a common software release life cycle pattern balancing innovation and stability, similar to many other software projects.

Supply Chain Management

Analogy in process control

Just like supply chains balance new product launches with reliable inventory, Jenkins versioning balances new features with stable releases to keep software delivery smooth.

Common Pitfalls

#1 Upgrading Jenkins directly from an old LTS to the latest weekly without testing.

Wrong approach:

Download and install latest weekly Jenkins over old LTS without backup or plugin checks.

Correct approach:

Backup Jenkins data, test upgrade in staging, verify plugin compatibility, then upgrade stepwise from old LTS to newer LTS or weekly.

Root cause:

Underestimating the complexity of Jenkins upgrades and plugin dependencies.

#2 Assuming all plugins work with the Jenkins version you have.

Wrong approach:

Install plugins without checking their compatible Jenkins versions, leading to errors.

Correct approach:

Check plugin documentation for compatible Jenkins versions before installation or upgrade.

Root cause:

Ignoring plugin compatibility requirements.

#3 Using weekly Jenkins versions in production for critical systems.

Wrong approach:

Deploy weekly Jenkins releases directly in production environments.

Correct approach:

Use Jenkins LTS versions in production to ensure stability and fewer bugs.

Root cause:

Prioritizing new features over stability in critical environments.

Key Takeaways

Jenkins offers two main version types: weekly releases with new features and LTS releases focused on stability.

Choosing between weekly and LTS depends on your need for innovation versus reliability in your automation pipelines.

LTS versions are carefully selected and tested snapshots of weekly releases, making them safer for production use.

Upgrading Jenkins requires careful planning, including backups and plugin compatibility checks, to avoid downtime.

Understanding Jenkins versioning helps maintain smooth software delivery and prevents common automation failures.