Part 2:(Amazon ELB Series) ELB Implementation Architectures

ELB Architecture 1: Single Server Setup

• Having an Amazon ELB configured before Single Web/App EC2 instance is not a common approach
• Not recommended because no significant benefit to the application

ELB Architecture 2: Multi-Server setup inside an AZ

• HTTP/S requests hitting the ELB are directed to Web/App EC2
• Multiple Web/App EC2 instances can reside inside the same AZ under the ELB tier
• Simple Round Robin , Round Robin with Session Sticky algorithms can be configured
• ELB Load Balances the requests between the Web/App EC2 instances

ELB Architecture 3: Across Multiple AZ's inside a Region

• HTTP/S requests hitting the ELB are directed to Web/App EC2
• Multiple Web/App EC2 instances can reside across multiple AZ’s inside a AWS region
• Simple Round Robin , Round Robin with Session Sticky algorithms can be configured
• ELB is doing Multi-AZ load balancing

ELB Architecture 4: ELB with Amazon Auto Scaling

• HTTP/S requests hitting the ELB are directed to Web/App EC2
• Web/App EC2 are configured with Amazon AutoScaling to scale out/down inside an AZ
• Amazon ELB can direct the load seamlessly to the Web/App EC2 instances configured with Amazon AutoScaling

ELB Architecture 5 : ELB with Amazon AutoScaling across AZ's

Web/App EC2 are configured with Amazon AutoScaling to scale out/down across AZ’s inside a Region

Amazon ELB can direct the load seamlessly to the Web/App EC2 instances configured with Amazon AutoScaling

Highly recommended approach