AWS Global Infrastructure is the backbone of AWS. It is comprised of AWS Regions, Availability Zones and Edge locations. Having a solid grasp of these concepts is critical for solutions architects because designing systems with an understanding of the AWS global infrastructure is the key to make them resilient and high-performing.
- AWS Regions
AWS Regions represent separate geographical areas across the world where you can host your resources. Currently, there are around 24 AWS Regions across the globe that span North America, South America, Europe, Asia Pacific and the Middle East. Each region is independent of others, and AWS strives to keep the regions isolated, which ensures region-level fault tolerance.
AWS Regions Code US East (Ohio) us-east-2 Asia Pacific (Mumbai) ap-south-1 EU (Ireland) eu-west-1 … … - Availability Zones
In contrast, Availability Zones are data centers in specific regions. Each region has multiple, isolated locations known as Availability Zones that act as a fail-safe for your applications. If a disaster impacts one zone—like a power outage, for example—your applications remain available in another zone. The number of Availability Zones per region varies, but generally, it ranges from two to six.
AWS Region Region Code Number of AZs South AM (Sao Paulo) sa-east-1 3 Asia Pacific (Tokyo) ap-northeast-1 5 EU (London) eu-west-2 3 … … …
Designing Systems on AWS
Deploying applications across multiple Availability Zones in the same region can help to achieve high availability and fault tolerance. For example, when architecting a web application, you can distribute your EC2 instances in multiple Availability Zones. If one of the zones becomes unavailable—your application doesn’t suffer as traffic can be redirected to instances in other zones.
# Creating a load balancer across multiple zones
aws elb create-load-balancer \
–load-balancer-name my-load-balancer \
–listeners Protocol=HTTP,LoadBalancerPort=80,InstanceProtocol=HTTP,InstancePort=80 \
–availability-zones “us-west-2a” “us-west-2b”
A key to remember here is that data transfer between Availability Zones in the same region is charged, but the cost is significantly less than data transfer across regions.
For many businesses that operate in specific geographical regions, choosing to host their applications in the AWS Region nearest to them can help ensure optimal latency and performance. However, for global businesses, it’s often more efficient to host applications in multiple regions to better serve a global audience.
As a final point, understanding the AWS Global Infrastructure—its regions and availability zones is not just crucial for passing the AWS Certified Solutions Architect – Associate (SAA-C03) exam, but also for designing and maintaining resilient and high-performing architectures on AWS.
Practice Test
True or False: An Availability Zone (AZ) in AWS spans over multiple geographical locations.
- True
- False
Answer: False
Explanation: An Availability Zone is a distinct location within a region that is insulated from failures in other Availability Zones.
Multiple Choice: Which of the following is not a component of AWS Global Infrastructure?
- a) Regions
- b) Availability Zones
- c) Edge Locations
- d) AWS Clusters
Answer: d) AWS Clusters
Explanation: The AWS Global Infrastructure comprises of Regions, Availability Zones, and Edge Locations. AWS Clusters are not part of this infrastructure.
Multiple Choice: Local Zones are typically located where?
- a) In every AWS Region
- b) In large population, industry, and IT centers
- c) In major cloud computing hubs
- d) Only in North America
Answer: b) In large population, industry, and IT centers
Explanation: AWS Local Zones are a type of infrastructure deployment that places AWS compute, storage, database, and other services closer to users in large population, industry, and IT centers.
True or False: Availability Zones in a region are always interconnected.
- True
- False
Answer: True
Explanation: Availability Zones within a region are interconnected with fast, private fiber-optic networking.
Single Select: Which AWS service would you use to speed up the delivery of your content to users around the world?
- a) CloudFront
- b) DynamoDB
- c) Route53
- d) S3
Answer: a) CloudFront
Explanation: CloudFront is a fast content delivery network (CDN) service that securely delivers data, videos, applications, and APIs to customers globally.
True or False: AWS does not have any infrastructure in South America.
- True
- False
Answer: False
Explanation: AWS has regions and infrastructure deployed in South America, specifically in Sao Paulo, Brazil.
Multiple Choice: What are the primary benefits of deploying applications across multiple Availability Zones?
- a) High Availability
- b) Fault Tolerance
- c) Scalability
- d) All of the above
Answer: d) All of the above
Explanation: Using multiple Availability Zones increases the availability, fault tolerance, and scalability of the applications.
Single Select: What is the maximum number of Availability Zones that an AWS Region can have?
- a) 6
- b) 12
- c) 18
- d) There is no maximum
Answer: d) There is no maximum
Explanation: Some AWS regions have more than 6 Availability Zones.
True or False: The AWS Global Accelerator is a networking service that improves the availability and performance of the applications with local and global users.
- True
- False
Answer: True
Explanation: AWS Global Accelerator is a service that improves the availability and performance of applications with local or global users. It provides static IP addresses that act as a fixed entry point to your application endpoints in a single or multiple AWS Regions.
Multiple Choice: What is the purpose of AWS Edge Locations?
- a) To store data close to users
- b) To provide end users with lower latency
- c) To backup data for Availability Zones
- d) All of the above
Answer: b) To provide end users with lower latency
Explanation: Edge Locations are sites deployed in major cities and highly populated areas around the world. They are used by CloudFront (AWS Content Delivery Network) to cache content close to users, providing them with lower latency.
Interview Questions
What can you tell about the AWS Global Infrastructure?
AWS Global Infrastructure is made up of multiple highly secured facilities known as data centers. These data centers are spread worldwide and grouped into geographic areas called Regions. Each Region has two or more Availability Zones, which provide customers the agility to operate production applications and databases that are more highly available, fault-tolerant, and scalable.
How many availability zones are there in a region in AWS?
Typically, each AWS Region has at least two or more Availability Zones. Some regions have as many as six Availability Zones.
What is the main purpose of AWS Regions?
AWS Regions are physical areas around the world where AWS has data centers. They are designed to allow users to set geographical controls on their data, minimize latency by providing services closer to end users and offer data redundancy across physical locations.
Define the term ‘Availability Zone’ in the context of AWS.
In AWS, an Availability Zone (AZ) is a distinct physical location within a region. Each AZ is isolated, but the AZs in a region are connected through low-latency links. Availability Zones provide users with the ability to operate applications and databases that are more highly available, fault-tolerant, and scalable than would be possible from a single data center.
What is the function of Edge Locations in AWS?
Edge Locations are sites that AWS uses to cache data for distribution to end users to reduce latency. In essence, they serve as a bridge between users and AWS’s data centers, further reducing the latency when end users access web content.
Can an EC2 instance be moved from one Availability Zone to another?
An EC2 instance cannot be moved directly between Availability Zones. However, you can create an AMI (Amazon Machine Image) of your instance and then launch a new instance in the desired Availability Zone.
How are Regions and Availability Zones related?
An AWS region is a physical location around the world where AWS clusters data centers. Each region consists of several isolated and physically separate zones within a geographical area known as Availability Zones.
What is the benefit of distributing applications across multiple Availability Zones within a Region?
Distributing applications across multiple Availability Zones within a Region provides high availability, fault tolerance, and scalability. If one Availability Zone becomes unreachable due to failures, network faults, or disasters, the application can continue running in another zone.
How does an AWS Local Zone function?
An AWS Local Zone is a type of extension of an AWS Region that places AWS compute, storage, database, and other services closer to large population, industry, and IT centers. They are designed to handle data residency requirements and certain types of applications that need the lowest possible latency.
What are the most commonly used services in an Availability Zone?
The most commonly used services in an Availability Zone include Amazon Elastic Compute Cloud (EC2), Amazon Relational Database Service (RDS), and Amazon Simple Storage Service (S3). These services enhance the flexibility, scalability, and reliability of applications.
Can data be automatically replicated to another region?
Yes, certain AWS services like Amazon S3, DynamoDB, and RDS offer features to replicate data across different regions to ensure high availability and durability.
How many AWS regions are currently available worldwide?
As of April 2022, there are 27 publicly available AWS regions worldwide.
What is an AWS Outpost?
AWS Outposts is a fully managed service that extends AWS infrastructure, services, APIs, and tools to virtually any datacenter, co-location space, or on-premises facility for a truly consistent hybrid experience.
How are AWS Local Zones and AWS Wavelength similar?
Both AWS Local Zones and AWS Wavelength bring AWS services to the edge of the network, thus reducing latency for end-users. While Local Zones are general-purpose and suitable for a wide range of applications, Wavelength is specifically designed for ultra-low latency applications for mobile devices and end-users.
How can I identify the regions with my required AWS services?
AWS provides an online “Region Table” that lists the services available in each Region. You can refer to this table to identify the Regions that provide the AWS services you require.