Spring cloud loadbalancer - Feign + SimpleDiscoveryClient with healthcheck/retry

Question

I'm struggling to switch from Ribbon to Spring Cloud Loadbalancer after upgrading spring cloud versions. Setting up the SimpleDiscoveryClient with Feign was easy. But the simplediscovery client is 'too simple'. I want to add at least a healthcheck so it doesn't use an instance that is potentially down & preferably also a retry mechanism. I've read the docs over & over but cannot find an easy way to set this up.

https://docs.spring.io/spring-cloud-commons/docs/current/reference/html/#instance-health-check-for-loadbalancer I found this example custom config for the health check, but it doesn't work.

public class CustomLoadBalancerConfiguration {

@Bean
public ServiceInstanceListSupplier discoveryClientServiceInstanceListSupplier(
        ConfigurableApplicationContext context) {
    return ServiceInstanceListSupplier.builder()
                .withDiscoveryClient()
                .withHealthChecks()
                .build(context);
    }
}

if I run it as is, it throws the following missing bean error: Method discoveryClientServiceInstanceListSupplier in XXX.CustomLoadBalancerConfig required a bean of type 'org.springframework.web.client.RestTemplate' that could not be found.

Can anyone give me some pointers on how to get this working or how I can replicate the ribbon behavior?

score 0 · Answer 1 · answered Aug 09 '21 at 21:34

0

Add the below RestTemplate Bean in your configuration.

@Bean
public RestTemplate restTemplate() {
    return new RestTemplate();
}

answered Aug 09 '21 at 21:34

broken98

43
6

score 0 · Answer 2 · answered Apr 19 '22 at 06:10

Try adding the following to your application class

@LoadBalancerClients(defaultConfiguration = LoadBalancerClientConfiguration.class)
public class GatewayApplication {

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

This will enable the creation of DiscoveryClientServiceInstanceListSupplier (note the class itself is not available in the context, so you can't just autowire it for testing).

Spring cloud loadbalancer - Feign + SimpleDiscoveryClient with healthcheck/retry

2 Answers2