What is Elastic Load Balancing in AWS?
3 min read
Elastic Load Balancing (ELB) is a service offered by Amazon Web Services (AWS) that distributes incoming traffic across multiple resources such as AWS EC2 Instances, Containers, IP Addresses, and Lambda Functions. The primary purpose of ELB is to improve the availability and fault tolerance of applications by evenly distributing incoming traffic across multiple resources.
ELB prevents any single resource from being overwhelmed and ensures that the application remains responsive and available. ELB improves the overall performance, scalability and availability of your application.
A load balancer acts as a single point of contact for all incoming web traffic to your Auto Scaling group. This means that as you add or remove Amazon EC2 instances in response to the amount of incoming traffic, these requests route to the load balancer first. Then, the requests spread across multiple resources that will handle them. For example, if you have multiple Amazon EC2 instances, Elastic Load Balancing distributes the workload across the multiple instances so that no single instance has to carry the bulk of it.
Although Elastic Load Balancing and Amazon EC2 Auto Scaling are separate services, they work together to help ensure that applications running in Amazon EC2 can provide high performance and availability.
Key Points of AWS ELB
Distributes Traffic: ELB automatically routes incoming traffic across multiple targets, such as EC2 instances, containers, and IP addresses. This helps to prevent any single server from becoming overloaded.
Improves Scalability: ELB can automatically scale to handle changes in traffic demand. This means that your application can continue to function properly even during periods of high traffic.
Maintains Availability: ELB monitors the health of its registered targets and only routes traffic to the healthy ones. If a target becomes unhealthy, ELB will automatically remove it from rotation and route traffic to the remaining healthy targets.
Multiple Load Balancer Types: There are different types of ELBs available, each suited for different needs. These include Application Load Balancers, Network Load Balancers, and Gateway Load Balancers.
Conclusion
Elastic Load Balancing simplifies the process of distributing incoming traffic across multiple resources, improves the fault tolerance and scalability of applications, and enhances the overall performance and availability of applications hosted on AWS.