Eureka vs linkerd: What are the differences?

Introduction

Eureka and Linkerd are both service mesh tools used for managing microservices in a distributed system. While they have similar goals, there are key differences between Eureka and Linkerd that set them apart in terms of features and functionality. This article will highlight the main differences between the two tools.

1. Service Discovery: Eureka primarily focuses on service discovery, providing a registry for microservices to register and discover each other. It acts as a central point for service registry and allows services to locate each other through a REST API. On the other hand, Linkerd is a full-fledged service mesh platform that includes service discovery as one of its features but also provides additional functionalities such as load balancing, circuit breaking, and request routing.

2. Traffic Control: Eureka mainly provides service discovery and does not offer advanced traffic control features. It lacks fine-grained control over traffic routing and load balancing. Linkerd, however, offers powerful traffic control capabilities. It allows for intelligent routing and load balancing based on service-level or application-level metrics, resiliency patterns, and even dynamic traffic splitting for A/B testing or canary releases.

3. Protocol Support: Eureka is primarily designed for applications that use RESTful APIs and operates at the application layer. It provides service registration and discovery for HTTP-based services. In contrast, Linkerd supports multiple protocols including HTTP/1.1, HTTP/2, gRPC, and especially focuses on supporting services that use the Finagle framework by providing additional features and integrations specific to that framework.

4. Observability: Eureka offers basic monitoring and health checking capabilities, allowing services to report their status and perform rudimentary health checks. However, it lacks advanced observability features like distributed tracing and metrics collection. Linkerd, on the other hand, provides extensive observability features out of the box, including distributed tracing with OpenTracing, metrics collection with Prometheus, and visualization of service dependencies.

5. Proxy Integration: Eureka acts as a service registry and does not include its own proxy component. It relies on other components or frameworks, such as Netflix Zuul, to handle proxied traffic. Linkerd, on the other hand, includes its own powerful proxy component called Linkerd Proxy. This proxy is specifically optimized for service mesh functionality and provides advanced features like automatic retries, timeouts, circuit breaking, and per-request load balancing.

In summary, Eureka is primarily a service registry and discovery tool, while Linkerd is a feature-rich service mesh platform that includes advanced traffic control, observability, and proxy functionalities. Linkerd stands out for its capability to handle traffic control, support for multiple protocols, observability features, and integrated proxy component.