SpringCloud：Spring Cloud Gateway中如何配置LoadBalancer

要在Spring-Cloud-Gateway中配置LoadBalancer，需要用到spring-cloud-starter-netflix-ribbon，因此需要将它引入。

pom.xml：

java代码：

import org.springframework.boot.SpringApplication;
import org.springframework.boot.autoconfigure.EnableAutoConfiguration;
import org.springframework.boot.autoconfigure.SpringBootApplication;

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

application.properties：

server.port=8080
spring.application.name=gateway_server

# default true
management.endpoint.gateway.enabled=true
management.endpoints.web.exposure.include=*

logging.level.org.springframework.cloud.gateway=TRACE

# default true
ribbon.eureka.enabled=false

# default true
spring.cloud.loadbalancer.ribbon.enabled=true
# default false
spring.cloud.gateway.actuator.verbose.enabled=true

########################################################################
spring.cloud.gateway.routes[0].id=my_route
spring.cloud.gateway.routes[0].uri=lb://my-load-balanced-service
spring.cloud.gateway.routes[0].predicates[0]=Path=/test/**

my-load-balanced-service.ribbon.listOfServers=localhost:9090, 127.0.0.1:9090
my-load-balanced-service.ribbon.NFLoadBalancerRuleClassName=com.netflix.loadbalancer.RoundRobinRule

或者application.yaml：

server:
port: 8080

spring:
application:
name: gateway_server

spring:
cloud:
gateway:
routes:
- id: my_route
uri: lb://my-load-balanced-service
predicates:
- Path=/test/**

my-load-balanced-service:
ribbon:
listOfServers: localhost:9090, 127.0.0.1:9090
NFLoadBalancerRuleClassName: com.netflix.loadbalancer.RoundRobinRule

可以从com.netflix.client.config.CommonClientConfigKey这类中找到其它可配置的参数。

注意：lb://后面的一定不要使用下划线，即不要使用比如：my_load_balanced_service这种形式，否则LoadBanancer不会起作用。

NFLoadBalancerRuleClassName中可以配置的值：

其它可配置项：

.ribbon.NFLoadBalancerClassName: ILoadBalancer
.ribbon.NFLoadBalancerRuleClassName: IRule
.ribbon.NFLoadBalancerPingClassName: IPing
.ribbon.NIWSServerListClassName: ServerList
.ribbon.NIWSServerListFilterClassName: ServerListFilter

下表中列出了Spring Cloud Netflix为Ribbon提供的默认值：

Bean Type

Bean Name

Class Name

IClientConfig

ribbonClientConfig

DefaultClientConfigImpl

IRule

ribbonRule

ZoneAvoidanceRule

IPing

ribbonPing

DummyPing

ServerList

ribbonServerList

ConfigurationBasedServerList

ServerListFilter

ribbonServerListFilter

ZonePreferenceServerListFilter

ILoadBalancer

ribbonLoadBalancer

ZoneAwareLoadBalancer

ServerListUpdater

ribbonServerListUpdater

PollingServerListUpdater

如果创建了以上类型的一个bean，并将它们放入使用了@RibbonClient的一个配置中，默认值将会被覆盖。

完成以上工作后，通过访问比如：http://127.0.0.1:8080/test/test.jsp，LoadBalancer就会将请求转发到http://127.0.0.1:9090/test/test.jsp，或http://localhost:9090/test/test.jsp

参考文档

Spring Cloud Gateway：The LoadBalancerClient Filter
https://cloud.spring.io/spring-cloud-gateway/reference/html/#the-loadbalancerclient-filter

Spring Cloud Netflix： Client Side Load Balancer: Ribbon
https://cloud.spring.io/spring-cloud-static/spring-cloud-netflix/2.2.1.RELEASE/reference/html/#spring-cloud-ribbon

Working with load balancers
https://github.com/Netflix/ribbon/wiki/Working-with-load-balancers#components-of-load-balancer

Client Side Load Balancing with Ribbon and Spring Cloud
https://spring.io/guides/gs/client-side-load-balancing/

spring-cloud-gateway负载普通web项目
https://www.cnblogs.com/bener/p/10638814.html