ELB & ASG
ELB & ASG in Plain Terms
Imagine you run a popular online store. During a holiday sale, traffic spikes, and you need more servers to handle the load. When traffic dies down, you don't want to pay for those extra servers. And of course, you want to distribute incoming customers evenly across all your servers so that no single server is overwhelmed. That's where AWS ELB (Elastic Load Balancer) and ASG (Auto Scaling Group) come in.
What is an Elastic Load Balancer (ELB)?
An Elastic Load Balancer is a service that automatically distributes incoming application traffic across multiple targets—such as EC2 instances, containers, or IP addresses—across different availability zones.
Key Benefits of ELB:
- High Availability: Routes requests to healthy servers, bypassing any that are down or unhealthy.
- Scalability: Automatically accommodates increased or reduced traffic without manual intervention.
- Security: Integrates with AWS services like AWS Certificate Manager (ACM) for HTTPS/SSL offloading, and can also work with AWS Web Application Firewall (WAF) for extra protection.
Key ELB & ASG Concepts
Practical Use Cases
Handle traffic spikes during flash sales or holiday seasons.
Benefit: Prevent slow load times or server crashes during high-traffic periods.
Manage fluctuating traffic throughout the day for social media or gaming apps.
Benefit: Reduce costs during off-peak times while maintaining performance during peak times.
Ensure near-100% uptime across multiple Availability Zones.
Benefit: Minimize downtime and reduce the risk of single points of failure.
Route traffic to multiple services, each with its own scaling rules.
Benefit: Achieve flexibility and resilience as each microservice adapts to its own workload patterns.
ELB & ASG Best Practices Checklist
ELB and ASG work together to create a robust, scalable, and highly available infrastructure. By distributing traffic and automatically adjusting capacity, they help ensure your applications can handle varying loads efficiently and cost-effectively.