AWS Regions and Availability Zones

AWS Regions

AWS organizes its data centers into distinct geographical areas called regions. Currently, there are 33 regions launched worldwide. Each dot on the map represents a region, which consists of a group of data centers spread across that geographical area.

AWS Global Infrastructure Map

Every AWS region is identified by both a geographical name and a region code. The geographical name reflects the region’s location. For example, in the United States, there is a region in Northern Virginia called the Northern Virginia Region (N. Virginia). Its code is us-east-1, indicating that it was the first region created in the eastern U.S.

AWS regions are completely independent from each other. This means that your data will not be replicated across regions unless you explicitly authorize it.

When choosing a region to host your applications or data pipelines, consider these four key factors:

1. Latency: Select a region close to your end users to minimize delays.
2. Cost: Resource pricing can vary between regions.
3. Compliance: Certain regulations may require you to store data in specific geographic locations.
4. Service availability: Not all AWS services are available in every region

Availability Zones (AZs)

Within each region, AWS divides its data centers into availability zones (AZs). Every region includes at least three AZs, which are isolated and physically separated from each other. According to AWS, "AZs are physically separated by a meaningful distance, typically many kilometers, and all are within 100 km (60 miles) of each other."

Each AZ consists of one or more distinct data centers with redundant power, networking, and physical security. The AZs in a region are interconnected through high-speed, low-latency links.

Availability zones are named using a region code followed by a letter. For example, us-east-1a refers to an AZ within the us-east-1 (Northern Virginia) region.

The primary reason for having multiple AZs in a region is to ensure high availability and fault tolerance. By hosting your applications and data across multiple AZs, your system remains unaffected if one AZ becomes unavailable due to power failures or natural disasters.

References

1. Regions and Availability zones

2. AWS Global Infrastructure