Application Load Balancer - ALB

An Application Load Balancer (ALB) is a service that distributes network traffic at the application layer among various targets to enhance the availability and scalability of applications. Typically utilized in cloud computing and web applications, an ALB helps balance the load on different servers or resources, ensuring that no single resource is overwhelmed, thereby improving application performance and availability.

Here are some key features and functions of an Application Load Balancer:

1. Traffic Distribution: An ALB distributes incoming traffic across different servers or resources to balance the load, ensuring that no single resource is overwhelmed and improving application performance and availability.

2. Scalability: ALBs support application scaling by automatically adding new instances or resources and distributing traffic accordingly, facilitating the handling of increased demand.

3. TLS Support: An ALB can support Transport Layer Security (TLS) for secure data transmission, encrypting traffic between the client and the load balancer, as well as between the load balancer and the targets.

4. Content-Based Routing: ALBs can route traffic based on the content of the request (e.g., URL paths, hostnames), allowing for flexible configuration in applications with different components or services.

5. Health Monitoring: An ALB continuously monitors the health of targets to ensure that traffic is only directed to healthy instances or resources. If a target is deemed unhealthy, traffic is redirected to healthy targets.

6. WebSockets Support: ALBs can also support WebSockets, a communication protocol for bidirectional communication over the Hypertext Transfer Protocol (HTTP).

7. Integrated Protocol Features: ALBs can handle protocols such as HTTP, HTTPS, TCP, and WebSocket, covering a wide range of use cases.

Application Load Balancers are often integral to cloud platforms like Amazon Web Services (AWS) or Microsoft Azure and play a crucial role in ensuring the availability, scalability, and reliability of applications in the cloud.