As more and more applications are moving to the cloud, ensuring high availability and reliability of these applications is becoming increasingly important. To achieve this, architects need to design and deploy global applications architecture that can handle failures and outages in different regions and availability zones (AZs).
Amazon Web Services (AWS) provides various options for architects to design and deploy global applications architecture. These options differ in terms of complexity, cost, and availability. In this article, we’ll explore some of the most common AWS global applications architecture patterns, and compare them based on their pros and cons.
Single Region, Single AZ
The single region, single AZ architecture is the simplest of all AWS global applications architecture. It involves deploying a single instance of your application in a single region with no redundancy. While this architecture is simple to set up and manage, it’s not highly available. Failure of the single AZ can result in downtime, and there’s no automatic failover to a healthy AZ. This architecture is suitable for development and test environments or applications that don’t require high availability.
Single Region, Multi AZ
The single region, multi AZ architecture involves deploying a single instance of your application in a single region with multiple AZs for redundancy. This architecture provides high availability, with automatic failover to a healthy AZ in case of AZ-level failures. However, it’s limited in scalability and can be costly due to the need for additional resources in each AZ. This architecture is suitable for applications that require high availability, but with limited scalability.
Multi-Region, Active-Passive
The multi-region, active-passive architecture involves deploying two instances of your application in different regions, with one instance actively serving traffic and the other as a passive standby. This architecture provides high availability, with automatic failover to the passive standby in case of region-level failures. However, recovery times can be longer due to manual failover. This architecture is suitable for applications that require high availability and have relatively short recovery time objectives (RTO).
Multi-Region, Active-Active
The multi-region, active-active architecture involves deploying multiple instances of your application in different regions, with each instance actively serving traffic. This architecture provides high availability, with no downtime during failovers or maintenance. It also provides better scalability than the single region, multi AZ architecture. However, this architecture is more complex to set up and manage, and can be costly due to the need for additional resources in each region. This architecture is suitable for applications that require high availability, no downtime during maintenance, and better scalability.
Comparison Table
Here’s a comparison table of the different AWS global applications architecture patterns:
| Architecture Pattern | Description | Pros | Cons |
|---|---|---|---|
| Single Region, Single AZ | A single instance of your application is running in a single region with no redundancy. | Simple to set up and manage | Not highly available, failure of the single AZ can result in downtime |
| Single Region, Multi AZ | A single instance of your application is running in a single region with multiple AZs for redundancy. | High availability, automatic failover to a healthy AZ | Limited scalability, higher cost |
| Multi-Region, Active-Passive | Two instances of your application are running in different regions, with one instance actively serving traffic and the other as a passive standby. | High availability, automatic failover to the passive standby in case of region-level failures | Longer recovery times due to manual failover |
| Multi-Region, Active-Active | Multiple instances of your application are running in different regions, with each instance actively serving traffic. | High availability, no downtime during failovers or maintenance, better scalability | Higher complexity, more difficult |