[AWS] How to develop Redundant Web System ~Part1: Subnet Creation~

First of all

In this article, let me explain how to develop redundant web site by AWS. Redundant configuration is one of basic architecture. If you want to be a solution architect, you should understand it in detail. In part1, let me explain subnet creation.

System Requirement

Web site can be accessed on the Internet with FQDN
Redundant server configuration for incident recovery
Manual switchover at the time of an incident.
Can develop additional servers if the web access is increased

System Configuration

System Configuration diagram is as below. Public Users access EC2 instance through ELB, Elastic Load Balancer. And static contents are provided by S3 through CloudFront.

Prepare Subnet

In this section, please create two subnet at least.

Different subnets need to be designated to ELB.

Firstly, access to VPC setting screen.

And, click “Subnets” button.

Then, click “Create subnet”,

Please designate existing VPC. If you have not created it, please prepare it by referring to below article.
https://eeengineer.com/aws-how-to-develop-temporary-web-system-part1-vpn-creation/

Input subnet name.
And, select Availability Zone and IPv4 CIDR block.
Then, click “Create subnet”.

New VPC is created as below !!

Please create another subnet by same procedure.

Subnet needs to be associated with route table that has route to Internet gateway. If your EC2 instance cannot be accessed, let’s check the route as below.

In the route table, please check if Internet Gateway is included in the Target.

Finally

This is the end of part1, VPC creation. In next part, let’s duplicate EC2 instance for redundant access.