Auto Scaling in AWS helps manage the number of EC2 instances based on application demand by maintaining a defined minimum and maximum number of instances in a collection known as an Auto Scaling Group. It utilizes launch configurations, scaling policies, and triggers through CloudWatch metrics to automatically adjust instance counts, ensuring high availability and redundancy across multiple Availability Zones. By integrating Auto Scaling with Elastic Load Balancing, traffic can be optimally routed to prevent any single instance from being overwhelmed.

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Auto Scaling Group (ASG)

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What is AutoScaling
➢ Auto Scaling helps you ensure that you have the correct number of Amazon EC2 instances available to
handle the load for your application.
You create collections of EC2 instances, called Auto Scaling groups.
➢ You can specify the minimum number of instances in each Auto Scaling group, and Auto Scaling ensures that
your group never goes below this size.
➢ You can specify the maximum number of instances in each Auto Scaling group, and Auto Scaling ensures that
your group never goes above this size.
➢ If you specify the desired capacity, either when you create the group or at any time thereafter, Auto Scaling
ensures that your group has this many instances.
➢ If you specify scaling policies, then Auto Scaling can launch or terminate instances as demand on your
application increases or decreases

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Configuring Auto Scaling in AWS
Launch
Configuration
Parameters for launching instances
Auto Scaling
Groups
Post-launch parameters
Auto Scaling
Policy
Scaling triggers
Scaling Event Act of scaling itself

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• Configuring Auto Scaling in AWS
Launch
Configuration
Set of parameters used to launch EC2 instances – AMI,
instance size, security groups
Auto Scaling
Groups
Defines the post-launch parameters
Auto Scaling
Policy
Rules for scaling or terminating autoscaled instances
Scaling Event Act of scaling itself
• AMI ID
• Instance size
• Block devices
• Key pairs
• Security groups

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• Configuring Auto Scaling in AWS
Launch
Configuration
Set of parameters used to launch EC2 instances – AMI,
instance size, security groups
Auto Scaling
Groups
Defines the post-launch parameters - AZ, ELB, min & max
servers to run
Auto Scaling
Policy
Rules for scaling or terminating autoscaled instances
Scaling Event Act of scaling itself
• Minimum & maximum number
of EC instances to run
• Cooldown parameters
• AZ & VPC ids where these
instances will run

6. Mahesh TR• Configuring Auto Scaling in AWS
Launch
Configuration
Set of parameters used to launch EC2 instances – AMI,
instance size, security groups
Auto Scaling
Groups
Defines the post-launch parameters
Auto Scaling
Policy
Rules for scaling or terminating autoscaled instances
Scaling Event Act of scaling itself
• Initiate scaling activity
• Use CloudWatch metrics as triggers
– EC2: CPU, disk, memory, network
– ELB: healthy instances, HTTP code, latency, request
count

7. Mahesh TR
• Configuring Auto Scaling in AWS
Launch
Configuration
Set of parameters used to launch EC2 instances – AMI,
instance size, security groups
Auto Scaling
Groups
Defines the post-launch parameters
Auto Scaling
Policy
Rules for scaling or terminating autoscaled instances
Scaling Event Act of scaling itself
• Act of scaling up/down
• Notification of scaling activity

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AutoScaling
• Auto Scaling dynamically adds and removes EC2 instances,
while Elastic Load Balancing manages incoming requests by
optimally routing traffic so that no one instance is
overwhelmed
• Auto Scaling helps to automatically increase the number of
EC2 instances when the user demand goes up, and decrease
the number of EC2 instances when demand goes down

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AutoScaling
• Autoscaling configuration requires the following :-
• Launch configuration which allows you to select an
• AMI
• Instance type
• IAM role (optional)
• Security group
• Key pair file

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AutoScaling
• High Availability & Redundancy
• Auto Scaling can span across multiple AZs, within the same
region
• When one AZ becomes unhealthy or unavailable, Auto
Scaling launches new instances in an unaffected AZ
• When the unhealthy AZs recovers, Auto Scaling redistributes
the traffic across all the healthy AZs
• It is recommended to take advantage of the safety and
reliability of geographic redundancy by using Auto Scaling &
ELB by spanning Auto Scaling groups across multiple AZs
within a region and then setting up ELB to distribute
incoming traffic across those AZs.

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THANK YOU!