Blue-green deployment for models in MLOps - Step-by-Step Execution

Process Flow - Blue-green deployment for models

Start with Blue environment live

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Deploy new model to Green environment

↓

Test Green environment model

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Switch traffic

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Green becomes live

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Blue environment idle, ready for next update

This flow shows how a new model is deployed to a separate environment (Green) while the current model runs in Blue. After testing, traffic switches to Green if successful, else fixes are made.

Execution Sample

MLOps

Deploy model v2 to Green
Test Green model
If test passes:
  Switch traffic to Green
Else:
  Fix Green model

This pseudo-code shows the steps to deploy a new model version to the Green environment, test it, and switch traffic if tests pass.

Process Table

Step	Action	Environment State	Test Result	Traffic Routing
1	Blue environment live with model v1	Blue: v1 live, Green: idle	N/A	Traffic -> Blue
2	Deploy model v2 to Green	Blue: v1 live, Green: v2 deployed	N/A	Traffic -> Blue
3	Test Green model v2	Blue: v1 live, Green: v2 deployed	Pass	Traffic -> Blue
4	Switch traffic to Green	Blue: v1 idle, Green: v2 live	Pass	Traffic -> Green
5	Blue environment idle, ready for next update	Blue: idle, Green: v2 live	N/A	Traffic -> Green

💡 Traffic switched to Green environment after successful test; Blue environment is idle.

Status Tracker

Variable	Start	After Step 2	After Step 3	After Step 4	Final
Blue environment model	v1 live	v1 live	v1 live	idle	idle
Green environment model	idle	v2 deployed	v2 deployed	v2 live	v2 live
Traffic routing	Blue	Blue	Blue	Green	Green
Test result	N/A	N/A	Pass	Pass	N/A

Key Moments - 3 Insights

Why do we deploy the new model to the Green environment instead of updating Blue directly?

Deploying to Green keeps Blue live and serving traffic, so users are not affected if the new model has issues. This is shown in execution_table steps 1 and 2.

What happens if the Green model test fails?

If the test fails, traffic stays on Blue and the Green model is fixed before switching. This is implied by the decision branch in concept_flow and the absence of traffic switch in execution_table.

Why is the Blue environment kept idle after switching traffic?

Blue is kept idle as a backup to quickly roll back if needed, ensuring reliability. This is shown in execution_table step 5.

Visual Quiz - 3 Questions

Look at the execution_table at step 3, what is the test result for the Green model?

A Pass

B Fail

C Not tested

D Unknown

💡 Hint

Check the 'Test Result' column in execution_table row for step 3.

At which step does traffic switch from Blue to Green?

A Step 2

B Step 3

C Step 4

D Step 5

💡 Hint

Look at the 'Traffic Routing' column in execution_table to find when it changes to Green.

If the Green model test failed at step 3, what would happen to traffic routing?

A Switch to Green anyway

B Keep traffic on Blue

C Split traffic between Blue and Green

D Stop all traffic

💡 Hint

Refer to key_moments about test failure and traffic routing behavior.

Concept Snapshot

Blue-green deployment for models:
- Two environments: Blue (live) and Green (new)
- Deploy new model to Green, test it
- If tests pass, switch traffic to Green
- Blue becomes idle backup
- Enables zero downtime and quick rollback

Full Transcript

Blue-green deployment for models means having two environments: Blue and Green. Blue runs the current model live. We deploy the new model to Green and test it without affecting users. If tests pass, we switch user traffic to Green, making it live. Blue then becomes idle, ready to be a backup. This method avoids downtime and allows quick rollback if needed.