AWS Elastic Load Balancing (ELB) vs Eureka: What are the differences?

Introduction

AWS Elastic Load Balancing (ELB) and Eureka are two widely used load balancing services. While both help distribute traffic across multiple resources, there are key differences between them.

1. Scalability:

   • ELB: Elastic Load Balancing is a highly scalable service provided by AWS. It automatically scales up or down based on the incoming traffic, ensuring optimal performance.
   • Eureka: Eureka is an open-source load balancing solution used by Netflix. It is also designed to be scalable, allowing for the addition or removal of instances dynamically.

2. Integration:

   • ELB: Being an AWS service, ELB seamlessly integrates with other AWS services, such as Amazon EC2 and Auto Scaling, making it easier to manage the entire infrastructure.
   • Eureka: Eureka is commonly used in conjunction with Spring Cloud, making it a great choice for applications built with Java and Spring.

3. Health Checking:

   • ELB: AWS ELB performs automatic health checks on the registered instances, ensuring that only healthy instances receive traffic. It monitors the health of the instances and distributes traffic accordingly.
   • Eureka: Eureka includes a built-in health check mechanism, allowing it to verify the availability and health of registered instances. It marks instances as UP or DOWN based on health checks.

4. Load Balancer Algorithms:

   • ELB: AWS ELB offers multiple load balancing algorithms, including round-robin, least connections, and IP-based affinity. These algorithms distribute traffic evenly across the available instances.
   • Eureka: Eureka uses the round-robin algorithm by default. However, it can be easily customized to use other load balancing algorithms as well.

5. Service Discovery:

   • ELB: Elastic Load Balancing focuses primarily on load balancing and does not offer full-fledged service discovery features. It can distribute traffic to instances, but it does not provide comprehensive service registry and lookup capabilities.
   • Eureka: Eureka, on the other hand, provides robust service discovery functionalities. It offers service registration and lookup, allowing clients to dynamically discover and communicate with different services.

6. Pricing and Licensing:

   • ELB: AWS ELB is a managed service provided by Amazon Web Services. It follows the pay-as-you-go pricing model, where you pay based on the number of hours and data processed by the load balancer.
   • Eureka: Eureka is an open-source solution, making it free to use. However, it requires hosting and managing the Eureka server infrastructure, which may incur costs.

In Summary, AWS Elastic Load Balancing (ELB) is a scalable load balancing service provided by AWS, integrating well with other AWS services, while Eureka is an open-source load balancing solution commonly used with Spring Cloud, offering service discovery capabilities.