Blue Green Deployment
Blue and Green represent two production ready environments
A flip in the network interface decides the instance that will receive the request
The network flip makes the Staging environment the new production environment, and what was production becomes staging
With this type of deployment we get the opportunity to rollback to the previous version if any issue arises
Difficult to migrate databases using this approach
Draining: Getting users (sessions) from the old server to the new server
This is achieved in Azure using Application Gateway
Rolling Deployment
We have more that one server hosting the application, and new versions of application is deployed gradually to the servers
This type of deployment requires the new versions of the code to be backwards compatible
Risk is introduced gradually, if any issue occurs it will only effect a small percentage of the servers
Canary/Ring Deployment
A more sophisticated version of rolling deployment
Different users will receive different versions of the application
What is a Canary ?
- The name comes from a old mining particle
- Canary (type of bird) are more sensitive to toxic gases in the air, they acted as a danger detector
- If a canary fell over in its cage, it was clear that there was danger and everyone needed to be cleared
In the software world a small subset of the end users act like the canary