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

Introduction

In this article, we will compare and contrast two popular technologies: AWS Elastic Load Balancing (ELB) and Consul. Both of these solutions play a crucial role in managing and distributing traffic across multiple servers or nodes. However, they have distinct features and functionalities that set them apart. Let's explore the key differences between AWS Elastic Load Balancing (ELB) and Consul.

1. Deployment and Infrastructure:

   • AWS Elastic Load Balancing (ELB) is a fully managed service provided by Amazon Web Services (AWS). It is built on the AWS infrastructure and is tightly integrated with other AWS services. ELB can be deployed and managed using the AWS Management Console, CLI, or SDKs.
   • On the other hand, Consul is an open-source software developed by HashiCorp. It can be deployed on any infrastructure, whether it is hosted in a cloud provider like AWS, on-premises data centers, or hybrid environments. It offers more flexibility in terms of infrastructure choices.

2. Features and Scalability:

   • AWS Elastic Load Balancing (ELB) provides a rich set of features and auto-scaling capabilities. It supports various load balancing algorithms, SSL termination, health checks, cross-zone load balancing, and integration with other AWS services like Auto Scaling, AWS WAF, and AWS Shield. ELB can handle millions of requests per second and scale automatically based on the demand.
   • Consul, on the other hand, is primarily a service discovery and distributed key-value store solution. It focuses on providing a reliable and scalable mechanism for service registration, discovery, and health checks. While Consul can handle high scalability and can be used in conjunction with load balancers, it lacks some of the advanced features like automatic scaling and SSL termination offered by ELB.

3. Management and Visibility:

   • AWS Elastic Load Balancing (ELB) provides a centralized management console where administrators can configure, monitor, and troubleshoot their load balancers. It offers deep visibility into request logs, access logs, and metrics. ELB integrates seamlessly with other AWS services, making it easy to manage load balancers as part of the overall infrastructure.
   • Consul provides a web-based interface and a command-line interface for managing and monitoring the Consul cluster. It offers a rich set of APIs that allow developers to programmatically interact with Consul. While Consul provides visibility into service discovery and health checks, it may require additional tools or integrations for advanced monitoring and metrics.

4. Cost and Pricing:

   • AWS Elastic Load Balancing (ELB) follows a pay-as-you-go model, where customers are billed based on the amount of data processed and the number of load balancer instances deployed. The pricing includes features like SSL termination, cross-zone load balancing, and other advanced functionalities. ELB also offers cost optimization options like reserved capacity and spot instances.
   • Consul, being an open-source software, is free to use and does not have any direct licensing costs. However, it may require additional resources and efforts to deploy, manage, and maintain Consul in production environments. Organizations may need to consider infrastructure costs, operational expenses, and support requirements when comparing the overall cost of Consul with ELB.

5. Environment and Ecosystem:

   • AWS Elastic Load Balancing (ELB) is tightly integrated within the AWS ecosystem. It seamlessly integrates with other AWS services like EC2, Auto Scaling, ECS, EKS, CloudFormation, and more. ELB offers a comprehensive set of features compatible with a wide range of AWS services, making it a natural choice for AWS cloud-native applications.
   • Consul, being an open-source solution, has a broader ecosystem and can be used in different environments, whether it is on AWS, on-premises, or hybrid setups. Consul integrates well with other HashiCorp products, like HashiCorp Vault and Terraform, providing a comprehensive solution for service discovery, secrets management, and infrastructure as code.

6. Vendor Lock-in and Portability:

   • AWS Elastic Load Balancing (ELB) is a proprietary service provided by Amazon Web Services. While ELB offers seamless integration within the AWS ecosystem, it may create vendor lock-in. Applications tightly coupled with ELB may lose portability and face challenges if the organization decides to migrate away from AWS in the future.
   • Consul, being an open-source solution, provides more portability as it can be deployed on multiple infrastructures and cloud providers. It offers flexibility in terms of choosing the underlying infrastructure, making it easier to migrate or move applications across different environments.

**In Summary, AWS Elastic Load Balancing (ELB) is a managed service tightly integrated with AWS, offering advanced features and scalability, while Consul is an open-source solution providing service discovery, scalability, flexibility, and a broader ecosystem for different infrastructure choices. The choice between ELB and Consul depends on specific requirements, infrastructure preferences, and the level of integration with other services.