Differences between Netflix zuul and Spring cloud gateway

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Routing is an integral part of a microservice architecture. For example, `/` may be mapped to your web application, `/api/users` is mapped to the user service and `/api/shop` is mapped to the shop service.

Netflix Zuul

Zuul is a JVM-based router and server-side load balancer from Netflix. It provides a single entry to our system, which allows a browser, mobile app, or other user interface to consume services from multiple hosts without managing cross-origin resource sharing (CORS) and authentication for each one.

Netflix uses Zuul for the following:

Authentication
Insights
Stress Testing
Canary Testing
Dynamic Routing
Service Migration
Load Shedding
Security
Static Response handling
Active/Active traffic management

Dependency:

Zuul in your project, use the starter with a group ID of org.springframework.cloud and a artifact ID of spring-cloud-starter-netflix-zuul. See the Spring Cloud Project page for details on setting up your build system with the current Spring Cloud Release

<dependency>
   <groupId>org.springframework.cloud</groupId>
   <artifactId>spring-cloud-starter-netflix-zuul</artifactId>
</dependency>

Zuul Http Client

The default HTTP client used by Zuul is now backed by the Apache HTTP Client instead of the deprecated Ribbon RestClient. To use RestClient or okhttp3.OkHttpClient, set ribbon.restclient.enabled=true or ribbon.okhttp.enabled=true, respectively.

Zuul Filter

Zuul is a series of Filters that are capable of performing a range of actions during the routing of HTTP requests and responses.

Filter Types

There are several standard Filter types that correspond to the typical lifecycle of a request:

PRE Filters execute before routing to the origin. Examples include request authentication, choosing origin servers, and logging debug info.
ROUTING Filters handle routing the request to an origin. This is where the origin HTTP request is built and sent using Apache HttpClient or Netflix Ribbon.
POST Filters execute after the request has been routed to the origin. Examples include adding standard HTTP headers to the response, gathering statistics and metrics, and streaming the response from the origin to the client.
ERROR Filters execute when an error occurs during one of the other phases.

To make it a Zuul proxy server, all we need to do is add the @EnableZuulProxy annotation to our main class:

@SpringBootApplication
@EnableZuulProxy
public class ZuulApplication {

    public static void main(String[] args) {
        SpringApplication.run(ZuulApplication.class, args);
    }
}

We will be running the Zuul server on port 8050 and it also needs to register itself to the Eureka server. So in application.properties we’ll add the following:

Configuration

server.port=8050
spring.application.name=zuul-edge-server
eureka.client.serviceUrl.defaultZone=http://localhost:8761/eureka/

Spring Cloud Gateway

Just like Zuul , Spring Cloud Gateway provides means for routing requests to different services. Spring Cloud Gateway aims to provide a simple, yet effective way to route to APIs and provide cross cutting concerns to them such as: security, monitoring/metrics, and resiliency.

How to Include Spring Cloud Gateway

To include Spring Cloud Gateway in your project, use the starter with a group ID of org.springframework.cloud and an artifact ID of spring-cloud-starter-gateway

Dependency:

<dependency>
   <groupId>org.springframework.cloud</groupId>
   <artifactId>spring-cloud-starter-gateway</artifactId>
</dependency>

How It Works

The following diagram provides a high-level overview of how Spring Cloud Gateway works:

Clients make requests to Spring Cloud Gateway. If the Gateway Handler Mapping determines that a request matches a route, it is sent to the Gateway Web Handler. This handler runs the request through a filter chain that is specific to the request. The reason the filters are divided by the dotted line is that filters can run logic both before and after the proxy request is sent. All “pre” filter logic is executed. Then the proxy request is made. After the proxy request is made, the “post” filter logic is run.

Configuration

Shortcut configuration is recognized by the filter name, followed by an equals sign (=), followed by argument values separated by commas (,).application.yml

spring:
  cloud:
    gateway:
      routes:
      - id: after_route
        uri: https://example.org
        predicates:
        - Cookie=mycookie,mycookievalue

Conclusion

Zuul is built on servlet 2.5 (works with 3.x), using blocking APIs. It doesn’t support any long lived connections, like websockets.

Gateway is built on Spring Framework 5, Project Reactor and Spring Boot 2 using non-blocking APIs. Websockets are supported and it’s a much better developer experience since it’s tightly integrated with Spring.