Ever wondered how AWS provide robust infrastructure and high availability to our apps running in the cloud. Well in this blog post, we will answer the question. And the Answer is AWS Global Infrastructure. AWS maintains a global infrastructure that it uses to give you the peace of mind that my app is secure and is running in high availability. This does not mean it is by default as you have to configure it for high availability. So let's look into the parts of the AWS Global infrastructure and try to understand what it is.
The AWS Global Infrastructure consists of Regions, Availability Zones, Local Zones, Point of Presence etc. Have a look at the following image:-
In the above image, we have the region as the starting point. Everything is rapped inside the region. So what is a Region?
Region: Region is an actual geographic location maintained by AWS to provide a global footprint. Every Region provides full redundancy and connectivity to the network. All the regions in the AWS are connected using a global network so one region can talk to another region. Every region consistency of multiple Availability Zones which are different data centers to provide redundancy for your application. Let's look at the naming convention of the regions: eu-west-1 and eu-west-2. Here "eu" means that it is in the European continent, "west" means it is on the west side and "1" is the number of the AWS region in that area. eu-west-2 is the second AWS region on the west side of the European continent. All the regions also have their city names where they are located. eu-west-1 is in Ireland and eu-west-2 is in London.
There are special regions that have Gov cloud in their name. This is because these regions are utilised by govt. and are not used by any other clients of AWS.
Availability Zones: We talked about Availability Zones when we were defining regions. It is a fully isolated partition in AWS infrastructure. What does this mean? It means every zone is a physically different location using separate connections, power supply etc. This isolation guarantees redundancy and high availability for your applications. So if due to some reason, one availability zone goes down, the application hosted on the other one will be able to serve your customers. You have to configure your deployments to use availability zones. Some of the AWS services provide this by default like SQS. Every Availability Zone consists of multiple data centers.
Point of Presence: These locations are consists of Edge Locations and Regional Cache Servers. There is a CDN service by Amazon called Amazon Cloudfront which is used to cater for requests globally with low latency and high transfer speeds. Another service launched by AWS called Global Accelerator is also used to upgrade the performance of your application.
Local Zones: Local Zones are a new offering in AWS. These are extensions of the Regions in geographic proximity to users. Every Local Zone has their own internet connection and supports AWS Direct Connect. Local Zones are not available in every region and they have to be enabled to be utilised. The naming convention of the Local Zone is "us-west-2-laz-1a". Here us-west-2 is the name of the Region and lax-1a indicates the location.
That's a higher level picture of AWS Global infrastructure and we will talk more about them when we start looking into other AWS Services.