Just a place to put
some notes on the “AWS Essentials” course from https://linuxacademy.com
10) Auto Scaling
10.1) Auto Scaling Basics
Auto Scaling =
automates the process of adding (scaling
up) OR removing (scaling down)
EC2 instances based on traffic demand
for you application.
You can create collections of EC2 instances called Auto Scaling groups.
If you specify scaling
policies, then Auto Scaling can launch or terminate instances as demand on
your application increases or decreases.
Note: Auto scaling
is a service - not a physical offering - and will always stay in a VPC.
Auto Scaling
Components:
- Launch
Configuration: The EC2 template used when Auto Scaling needs to add an
additional server to your Auto Scaling
Group.
- Auto Scaling
Group: All the rules and settings that govern when an EC2 server is
automatically added or removed.
Pricing/Cost
Overview:
(1) Auto Scaling is FREE to use
(2) You will be charged for the resources that
Auto Scaling provisions!
10.2) Using Auto Scaling
Create Auto
Scaling Group:
Step 1: Create launch configuration
1. Choose AMI
2. Choose instance Type
3. Configure details
4. Add Storage
5. Configure Security Group
6. Review
Note: 1 -> 6
above are the same as creating an EC2 instance.
Step 2: Create Auto Scaling group
1. Configure Auto Scaling group details
2. Configure scaling policies
3. Configure Notifications
4. Configure Tags
5. Review
Image: Services
> EC2 > Auto Scaling: Launch Configurations > Create Auto Scaling
group
Image: 1. Configure
Auto Scaling group details
Note: Here you
select: Group size: Start with X instances
Image: 1. Configure
Auto Scaling group details: Advanced Details
Note: Here with ‘Receive traffic from
one or more load balancers’ ticked
Note: Here with ‘Health Check Type =
ELB’ (default is EC2)
Image: 2. Configure
scaling policies
Note: Here using ‘Use scaling
policies to adjust the capacity of this group’
Note: Here ‘Scale between 2 and
5 instances’
Note: Here with ‘Increase
Group Size’ and ‘Decrease Group Size’ policies set
Image: 3. Configure
Notifications
Note: Send a
notification to ... Whenever instances: launch
/ terminate / fail to launch / fail to terminate
10.3) Quiz: Auto Scaling Essentials
T: Auto scaling provides automation that contributes to highly
available and fault tolerant
architecture. Auto scaling is not used to send messages (this is SNS).
Q: What are the main two components of Auto Scaling?
A: Launch configuration and Auto Scaling group
Q: What best describes how you are charged for using Auto
Scaling?
A: Auto Scaling is free to use, but you are responsible
to pay for any AWS resources that Auto Scaling provisions.
T: Auto Scaling is the process of scaling up and scaling
down the number of EC2 instances based on traffic demands.
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