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

Introduction:

AWS Elastic Load Balancing (ELB) and Envoy are both popular solutions for load balancing in web applications. While they serve a similar purpose, there are key differences between them that make each unique and suitable for different use cases.

1. Architecture: AWS Elastic Load Balancing (ELB) is a managed load balancing service provided by Amazon Web Services. It leverages the global infrastructure of AWS and offers built-in support for various AWS services. Envoy, on the other hand, is an open-source proxy and communication bus. It can be deployed as a sidecar proxy or as a standalone network component.

2. Flexibility and Customization: Envoy provides a high level of flexibility and customization options. It allows users to define their own load balancing algorithms, request routing rules, and traffic management policies. In contrast, AWS ELB provides a more managed and simplified approach, offering predefined load balancing algorithms and limited customization options.

3. Integration with Service Mesh: Envoy is commonly used as a key component in service mesh architectures, such as Istio. It provides advanced features like traffic splitting, circuit breaking, and observability, which are essential for managing microservices-based applications. AWS ELB, although capable of load balancing across multiple services, does not offer the same level of integration with service mesh frameworks.

4. Platform Independence: Envoy can be deployed on various cloud platforms, including AWS, as well as on bare metal or on-premises infrastructure. This platform independence allows users to have consistent load balancing capabilities across multiple environments. In contrast, AWS ELB is tightly integrated with the AWS ecosystem and can only be used within the AWS cloud environment.

5. Cost and Pricing Model: AWS ELB follows a pay-as-you-go pricing model, where users are charged based on the amount of data processed and the specific features used. Envoy, being open-source, does not have any direct cost associated with it. However, deploying and managing Envoy may require additional resources and expertise, which can indirectly affect the overall cost.

6. Managed Service vs Self-Managed Proxy: AWS ELB is a managed service provided by AWS, which takes care of the underlying infrastructure, scaling, and maintenance tasks. This makes it a more hands-off solution for load balancing. Envoy, being an open-source proxy, requires self-management and administration, including updates, scaling, and configuration. This provides greater control and customizability but also requires additional effort and resources.

In Summary, AWS Elastic Load Balancing (ELB) is a managed load balancing service with integration into the AWS ecosystem, while Envoy is a flexible open-source proxy that can be used in various environments, heavily adopted in service mesh architectures like Istio. Envoy offers more customization options and platform independence, but requires self-management and lacks direct AWS integration.