RDS: Relational Database Service#

Amazon RDS (Relational Database Service) is AWS’ managed database service. If you don’t want to manage/host a database server yourself, you can let AWS handle provisioning, backups, patching, and monitoring. You get a database you can connect to with (nearly) zero operational overhead.

That said, RDS can get very expensive, especially if you have lots of data or need to operate in multiple AZs. But for many applications, the cost of a managed service is reasonable, and far outweighed by its benefits.

Boot.dev’s site is powered by a managed database service! It used to be on AWS RDS, and now its on Google Cloud SQL, but they’re basically the same thing.

Prerequisites#

Before we can create a database, we need to set up the networking infrastructure.

  1. Stand up a VPC named patientping, or use your existing one from the EC2 module, if you still have it.
  2. Stand up subnets within the VPC:
    1. A public subnet named patientping-public-a for your application servers
    2. A private subnet named patientping-private-a for your database
  3. Add an internet gateway (IGW) to the VPC, and make sure the public subnet’s route table points to it with a 0.0.0.0/0 default route.
  4. Make sure you have a key pair that you can use to SSH into EC2 instances.
  5. Stand up an Amazon Linux AMI server on a t3.micro instance, named patientping-web-v2, in your public subnet.
  6. Add a security group to the instance that allows you to SSH into it (named patientping-public or similar).
  7. Make sure your instance has a public IP address, preferably by attaching an Elastic IP to it.

This EC2 instance will serve as an application server that we’ll use to test connections to the database.

Whew! That’s a lot of setup. If you just completed the EC2 chapter, you might already have most of this in place. If so, feel free to reuse it.

Cost check: A t3.micro instance costs about $0.0104 per hour (~$7.60 per month). The public IP is free when attached to a running instance.

I recommend checking your work in the AWS CLI with these commands:

# Check your VPC
aws ec2 describe-vpcs --filters Name=tag:Name,Values=patientping

# Check your subnets
aws ec2 describe-subnets --filters Name=tag:Name,Values=patientping-public-a
aws ec2 describe-subnets --filters Name=tag:Name,Values=patientping-private-a

# Check your instance
aws ec2 describe-instances --filters Name=tag:Name,Values=patientping-web-v2

# Make sure your instance has a public IP
aws ec2 describe-instances --filters Name=tag:Name,Values=patientping-web-v2 --query 'Reservations[*].Instances[*].PublicIpAddress'

Once you have your VPC, subnets, IGW, and test instance ready, answer the multiple choice question. We’ll be creating an RDS database shortly.

Backward rds create-a-postgresql-database-in-aws Forward