tzouris
commented
1 month ago Process:
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Edit auto-scaling group
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Create new launch template version with new instance type (downscaling from m7g.8xlarge to m7g.4xlarge)
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Update the hardware specs in the task definition
Leaving 20% headroom for the ECS container and system resources 16 vCPUs & 64 GB memory available 10 vCPUs for the task (the max) - left empty since this is optional for EC2 instances 56 GB RAM for the task
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Make new LT version the default
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Update ASG with new LT version
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Increase the number of desired instances - a new instance is deployed
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Edit the default load balancer rule and put up the maintenance message
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Stop the ECS task
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Decrease the amount of desired instances on the ASG - the old instance is terminated
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Start the task
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Update the ALB target group - this took about 5 mins.
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Re-assign the Elastic IP to the new instance
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Check with VPN if site loads
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Restore the ALB rule - default points back to ecs-commons-wordpress target group
Duration of entire process: 20 mins
No security groups needed to be updated because of the way they are configured.
From m7g.8xlarge to m7g.4xlarge.