> For the complete documentation index, see [llms.txt](https://aws-postgresql-docs.beliciarodriguez.com/llms.txt). Markdown versions of documentation pages are available by appending `.md` to page URLs; this page is available as [Markdown](https://aws-postgresql-docs.beliciarodriguez.com/launching-instance/overview.md).

# Overview

This section reviews how to configure an AWS EC2 instance for a PostgreSQL server. We will

1. Create a security group that allows SSH and PostgreSQL server connections
2. Create a launch template 
3. Create server using auto scaling group (recommended) OR single instance
4. Attach an elastic IP address to our instance

Each of these subsections contains a video that walks through the instructions. 

### Why use AWS EC2 Auto Scaling over a single instance?

Auto-scaling adds or removes EC2 instances depending on changes in demand on the server. By using an auto scaling group, we can keep costs down by utilizing a smaller-sized instance (i.e 2 vCPUs) and adding instances when CPU usage increases. 

AWS EC2 auto scaling allows you to

* Assign a launch template to your auto scale group
  * A launch template is a saved pre-configuration of an instance that you can use to launch instances that have the same parameters
  * AWS uses your launch template to add instances you've previously configured when scaling out your application
    * Note: scaling out is when AWS **adds** instances when demand increases
* Configure the minimum, maximum, and desired number of instances for your application
* Prevent certain instances from being automatically terminated when scaling in 
  * Note: scaling in is when AWS **removes** instances when demand decreases
* Set a scaling policy that defines when instances should be added or removed from the group

### References

*Guides*

(1) Research Documentation for Creating Jupyter Hub Server Using AWS, <https://docs-jupyter.davidjachochavez.org/>

(2) Better Programming (Medium), *How to Provision a Cheap PostgreSQL Database in AWS EC2*, <https://medium.com/better-programming/how-to-provision-a-cheap-postgresql-database-in-aws-ec2-9984ff3ddaea>

*Documentations*

(3) Amazon EC2 Instance Types, <https://aws.amazon.com/ec2/instance-types/>

(4) Amazon EC2 On-Demand Instance Pricing,[ https://aws.amazon.com/ec2/pricing/on-demand/](https://aws.amazon.com/ec2/pricing/on-demand/)

(5) Amazon Elastic Compute Cloud, *Amazon EBS-optimized instances*, <https://docs.aws.amazon.com/AWSEC2/latest/UserGuide/ebs-optimized.html>

(6) AWS EC2 Auto Scaling User Guide, *What is Amazon EC2 Auto Scaling?,*[ https://docs.aws.amazon.com/autoscaling/ec2/userguide/what-is-amazon-ec2-auto-scaling.html](https://docs.aws.amazon.com/autoscaling/ec2/userguide/what-is-amazon-ec2-auto-scaling.html)

(7) Amazon EC2 Auto Scaling, *Creating a launch template for an Auto Scaling Group*, <https://docs.aws.amazon.com/autoscaling/ec2/userguide/create-launch-template.html>

(8) Amazon EC2 Auto Scaling, *Health checks for Auto Scaling,* [*https://docs.aws.amazon.com/autoscaling/ec2/userguide/healthcheck.html*](https://docs.aws.amazon.com/autoscaling/ec2/userguide/healthcheck.html)

(9) Amazon Elastic Compute Cloud, *Status checks for your instance*, <https://docs.aws.amazon.com/AWSEC2/latest/UserGuide/monitoring-system-instance-status-check.html>

(10) Amazon EC2 Auto Scaling, *Controlling which Auto Scaling instances terminate during scale in*, <https://docs.aws.amazon.com/autoscaling/ec2/userguide/as-instance-termination.html>

(11) Amazon EC2 Auto Scaling, *Target tracking scaling policies*, <https://docs.aws.amazon.com/autoscaling/ec2/userguide/as-scaling-target-tracking.html>

*Forums*

(12) StackOverflow, *What is the smallest AWS EC2 Instance I can run Postgres DB on?*,[ https://stackoverflow.com/questions/61718959/what-is-the-smallest-aws-ec2-instance-i-can-run-a-postgres-db-on](https://stackoverflow.com/questions/61718959/what-is-the-smallest-aws-ec2-instance-i-can-run-a-postgres-db-on)

(13) StackOverflow, *How does the ARM architecture differ from x86?*, <https://stackoverflow.com/questions/14794460/how-does-the-arm-architecture-differ-from-x86>