Migration strategies in Jenkins - Step-by-Step Execution

Process Flow - Migration strategies

Assess current Jenkins setup

↓

Choose migration strategy

↓

In-place

↓

Backup

↓

Upgrade

↓

Verify

↓

Migration complete

This flow shows the main steps in Jenkins migration: assess, pick a strategy, execute steps, verify, and complete.

Execution Sample

Jenkins

1. Backup Jenkins data
2. Install new Jenkins version
3. Restore data
4. Verify jobs and plugins
5. Switch to new Jenkins

This sequence shows a simple in-place Jenkins migration process.

Process Table

Step	Action	Result	Next Step
1	Backup Jenkins data	Data saved safely	Install new Jenkins version
2	Install new Jenkins version	New Jenkins installed	Restore data
3	Restore data	Data restored to new Jenkins	Verify jobs and plugins
4	Verify jobs and plugins	All jobs and plugins work	Switch to new Jenkins
5	Switch to new Jenkins	Users redirected to new Jenkins	Migration complete
6	Migration complete	Jenkins migration successful	End

💡 Migration stops after successful switch and verification

Status Tracker

Variable	Start	After Step 1	After Step 2	After Step 3	After Step 4	Final
BackupStatus	None	Completed	Completed	Completed	Completed	Completed
JenkinsVersion	Old	Old	New Installed	New Installed	New Installed	New Installed
DataRestored	No	No	No	Yes	Yes	Yes
JobsVerified	No	No	No	No	Yes	Yes
UserTraffic	Old Jenkins	Old Jenkins	Old Jenkins	Old Jenkins	New Jenkins	New Jenkins

Key Moments - 3 Insights

Why do we backup Jenkins data before installing the new version?

Backing up ensures no data loss during upgrade. As shown in execution_table step 1, backup is completed before installation.

What happens if jobs and plugins verification fails after restoring data?

You should not switch user traffic to new Jenkins until verification passes, preventing service disruption. This is implied in step 4 and 5.

Why switch user traffic only after verification?

Switching traffic too early risks users hitting a broken system. Execution_table shows traffic switches only after successful verification at step 5.

Visual Quiz - 3 Questions

Look at the execution_table, what is the JenkinsVersion after step 3?

A None

B Old

C New Installed

D Upgrading

💡 Hint

Check variable_tracker row 'JenkinsVersion' at 'After Step 3'

At which step does user traffic switch to the new Jenkins?

A Step 3

B Step 5

C Step 4

D Step 6

💡 Hint

Look at execution_table row for step 5 and variable_tracker 'UserTraffic'

If backup fails at step 1, what should happen next?

A Abort migration and fix backup

B Skip verification

C Proceed to install new Jenkins

D Switch user traffic immediately

💡 Hint

Refer to key_moments about importance of backup before installation

Concept Snapshot

Migration strategies in Jenkins:
1. Backup current data
2. Choose strategy: In-place, Blue-Green, or Canary
3. Install or setup new Jenkins
4. Restore data and verify jobs/plugins
5. Switch user traffic to new Jenkins
6. Decommission old Jenkins
Always verify before switching traffic to avoid downtime.

Full Transcript

This visual execution shows Jenkins migration strategies step-by-step. First, backup your Jenkins data to avoid loss. Then install the new Jenkins version or set up a new environment depending on your strategy. Restore your data and verify all jobs and plugins work correctly. Only after successful verification should you switch user traffic to the new Jenkins. Finally, decommission the old Jenkins instance. This process ensures a smooth migration with minimal downtime and risk.