Each region is completely independent. Each Availability Zone is isolated, but the Availability Zones in a region are connected through low-latency links. The following diagram illustrates the relationship between regions and Availability Zones.
Amazon EC2 resources are either global, tied to a region, or tied to an Availability Zone. For more information, see Resource Locations.
Regions
Each Amazon EC2 region is designed to be completely isolated from the other Amazon EC2 regions. This achieves the greatest possible fault tolerance and stability.
When you view your resources, you'll only see the resources tied to the region you've specified. This is because regions are isolated from each other, and we don't replicate resources across regions automatically.
When you launch an instance, you must select an AMI that's in the same region. If the AMI is in another region, you can copy the AMI to the region you're using. For more information, see Copying an AMI.
When you launch an instance, you can select an Availability Zone or let us choose one for you. If you distribute your instances across multiple Availability Zones and one instance fails, you can design your application so that an instance in another Availability Zone can handle requests.
You can also use Elastic IP addresses to mask the failure of an instance in one Availability Zone by rapidly remapping the address to an instance in another Availability Zone. For more information, see Elastic IP Addresses.
An Availability Zone is represented by a region code followed by a letter identifier; for example, us-east-1a. To ensure that resources are distributed across the Availability Zones for a region, we independently map Availability Zones to names for each AWS account. For example, the Availability Zone us-east-1a for your AWS account might not be the same location as us-east-1a for another AWS account.
To coordinate Availability Zones across accounts, you must use the AZ ID, which is a unique and consistent identifier for an Availability Zone. For example, use1-az1 is an AZ ID for the us-east-1 Region and it has the same location in every AWS account.
Viewing AZ IDs enables you to determine the location of resources in one account relative to the resources in another account. For example, if you share a subnet in the Availability Zone with the AZ ID use-az2 with another account, this subnet is available to that account in the Availability Zone whose AZ ID is also use-az2. The AZ ID for each VPC and subnet is displayed in the Amazon VPC console. For more information, see Working with VPC Sharing in the Amazon VPC User Guide.
As Availability Zones grow over time, our ability to expand them can become constrained. If this happens, we might restrict you from launching an instance in a constrained Availability Zone unless you already have an instance in that Availability Zone. Eventually, we might also remove the constrained Availability Zone from the list of Availability Zones for new accounts. Therefore, your account might have a different number of available Availability Zones in a region than another account.
Your account determines the regions that are available to you. For example:
An AWS account provides multiple regions so that you can launch Amazon EC2 instances in locations that meet your requirements. For example, you might want to launch instances in Europe to be closer to your European customers or to meet legal requirements.
An AWS GovCloud (US-West) account provides access to the AWS GovCloud (US-West) region only. For more information, see AWS GovCloud (US-West) Region.
An Amazon AWS (China) account provides access to the Beijing and Ningxia Regions only. For more information, see AWS in China.
The following table lists the regions provided by an AWS account. You can't describe or access additional regions from an AWS account, such as AWS GovCloud (US-West) or the China Regions.
The number and mapping of Availability Zones per region may vary between AWS accounts. To get a list of the Availability Zones that are available to your account, you can use the Amazon EC2 console or the command line interface. For more information, see Describing Your Regions and Availability Zones.
Regions and Endpoints
When you work with an instance using the command line interface or API actions, you must specify its regional endpoint. For more information about the regions and endpoints for Amazon EC2, see Regions and Endpoints in the Amazon Web Services General Reference.
For more information about endpoints and protocols in AWS GovCloud (US-West), see AWS GovCloud (US-West) Endpoints in the AWS GovCloud (US) User Guide.
AWS regions
An AWS Region is a geographical location with a collection of availability zones mapped to physical data centers in that region. Every region is physically isolated from and independent of every other region in terms of location, power, water supply, etc.
This level of isolation is critical for workloads with compliance and data sovereignty requirements where guarantees must be made that user data does not leave a particular geographic region. The presence of AWS regions worldwide is also important for workloads that are latency-sensitive and need to be located near users in a particular geographic area.
Inside each region, you will find two or more availability zones with each zone hosted in separate data centers from another zone. I’ll explain more later on why having at least two zones in a region is important.
The largest AWS region, us-east-1, has five zones. Moving forward, new AWS regions will have three or more zones whenever possible. When you create certain resources in a region, you will be asked to choose a zone in which to host that resource.
There are anywhere between two and five availability zones in an AWS Region. Moving forward, the standard will be three or more per region.
AWS availability zones
An availability zone is a logical data center in a region available for use by any AWS customer. Each zone in a region has redundant and separate power, networking and connectivity to reduce the likelihood of two zones failing simultaneously. A common misconception is that a single zone equals a single data center. In fact, each zone is backed by one or more physical data centers, with the largest backed by five.
While a single availability zone can span multiple data centers, no two zones share a data center. Abstracting things further, to distribute resources evenly across the zones in a given region, Amazon independently maps zones to identifiers for each account. This means the us-east-1a availability zone for one account may not be backed by the same data centers as us-east-1a for another account.
In each zone, participating data centers are connected to each other over redundant low-latency private network links. Likewise, all zones in a region communicate with each other over redundant private network links. These intra and inter-zone links are heavily used for data replication by a number of AWS services including storage and managed databases.
Why are availability zones such an important and foundational concept in Amazon Web Services? The diagram below illustrates a region with two zones where only one is being utilized. The architecture mirrors what a typical three-tier application running in a user’s single on-premises data center may look like. While there are redundant servers running in each tier, the data center itself is a single point of failure.
well! Thanks for providing the information
ReplyDeleteAWS Training
AWS Online Training
AWS certification training