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I have trouble with health-check with custom loadbalancer configuration from "say-hello" and "user" modules from 'complete' folder here.

Can you please check if I have miss something? Or do I need to set more configuration for using '.withHealthChecks()'?

Let me share how I tested.

1. Download "complete" folder and run "say-hello" with port 8090 and run "user" with port 8888.

2. Try accessing to "user" : http://localhost:8888/hi

3. Access localhost:8090, localhost:9092, localhost:8099 following RoundRobin rule (port 8090, 9092, 8099 described on 'https://github.com/spring-guides/gs-spring-cloud-loadbalancer/blob/main/complete/user/src/main/java/hello/SayHelloConfiguration.java')

4. Modify custom config like below from the file 'https://github.com/spring-guides/gs-spring-cloud-loadbalancer/blob/main/complete/user/src/main/java/hello/SayHelloConfiguration.java'.

   @bean
   @primary
   ServiceInstanceListSupplier serviceInstanceListSupplier(
   ConfigurableApplicationContext context
   ) {
   // return new DemoServiceInstanceListSuppler("say-hello");
   return ServiceInstanceListSupplier.builder()
   .withBase(new DemoServiceInstanceListSuppler("say-hello"))
   .withHealthChecks()
   .build(context);
   }

5. Run "user" again and try accessing to "user".

6. Got the error log and can not access to "say-hello".

2021-05-07 11:31:55.619 WARN 63497 --- [ parallel-5] o.s.c.l.core.RoundRobinLoadBalancer : No servers available for service: localhost
2021-05-07 11:31:55.619 WARN 63497 --- [ parallel-5] eactorLoadBalancerExchangeFilterFunction : LoadBalancer does not contain an instance for the service localhost
2021-05-07 11:31:55.619 WARN 63497 --- [ parallel-5] o.s.c.l.core.RoundRobinLoadBalancer : No servers available for service: localhost
2021-05-07 11:31:55.620 WARN 63497 --- [ parallel-5] eactorLoadBalancerExchangeFilterFunction : LoadBalancer does not contain an instance for the service localhost
2021-05-07 11:31:55.620 WARN 63497 --- [ parallel-5] o.s.c.l.core.RoundRobinLoadBalancer : No servers available for service: localhost
2021-05-07 11:31:55.620 WARN 63497 --- [ parallel-5] eactorLoadBalancerExchangeFilterFunction : LoadBalancer does not contain an instance for the service localhost

I creat new webflux client project run on tomcat without spring boot. but get exception:
Caused by: java.net.UnknownHostException: Failed to resolve 'say-hello' after 3 queries

what is wrong?

I was hoping to find some migration steps from Netflix Ribbon to Spring Cloud LoadBalancer in https://spring.io/guides/gs/client-side-load-balancing/ or in https://spring.io/guides/gs/spring-cloud-loadbalancer/.

So I have the properties for Netflix Ribbon: https://github.com/Netflix/ribbon/wiki/Getting-Started#the-properties-file-sample-clientproperties

I can group the properties in 3 categories:

• retry settings
• timeouts
• discovery settings

For the timeouts I have a possible solution to create a different load balanced restTemplate for each API called:

@Bean
@LoadBalanced
public RestTemplate restTemplate(RestTemplateBuilder builder, Environment env){
    builder.setReadTimeout(env.getProperty(SERVICE_NAME + ".ribbon.ReadTimeout", Duration.class, Duration.of(3L, ChronoUnit.SECONDS)));
    //builder.additionalInterceptors(...);
    //builder.errorHandler(...)
    return builder.build();
}

For the discovery settings, more exactly the static list of addresses I made a class that implements org.springframework.cloud.client.discovery.DiscoveryClient, but how should I deal with the retry settings, more exactly with MaxAutoRetriesNextServer ?

And is this the best approach to create a different restTemplate for each API called?

Update the guide to use the most recent Spring Boot version.

To do so, change the Spring Boot version in:

initial/build.gradle
initial/pom.xml
complete/build.gradle
complete/pom.xml