Deployment Strategies In AWS ASG - Terminate and Launch

  

Terminate and Launch: Terminate the existing instance and launch a new instance with updated LT.

In this strategy we will change the minimum number of instances to be running during the time of deployment. 

I have 5 EC2 instances under the ASG which are running on version LT1.

Setting minimum 10% -> Ensure 1 machine is actively taking traffic and others are updated.

Setting minimum 50% -> Ensure 3 machines are active and 2 are updated.

Setting minimum 90% -> Ensure 4 machines are active and 1 is updated.

Increasing the minimum will increase the deployment time.

Please find the below table for better understanding.

Instances #	Min Healthy Instances	Minimum Must Machines	Instances # Patched at a time
10	20%	2	8
10	30%	3	7
10	40%	4	6
10	50%	5	5
10	60%	6	4
10	70%	7	3
10	80%	8	2
10	90%	9	1