Load balancer does not have available server for client
118,255
Solution 1
After doing research, and with help of @Bloodysock, I found that I was missing registration of remote server in 'client-app' micro-service. The document is at Spring Cloud Netflix.
I used Ribbon without Eureka with configuration in application.yml in 'client-app' micro-service as:
movie-api:
ribbon:
listOfServers: http://localhost:8090
Solution 2
The problem is that your service doesn't know the host of requested service. If you are using Eureka, put this line on your .properties file:
eureka.client.fetchRegistry=true
OR .yml file:
eureka:
client:
fetch-registry: true
It'll make your service talk with Eureka and discover the host of the requested service.
Solution 3
If your Spring Cloud set up does not support specifying the servers in application.properties/application.yml, you have to configure the services URL in a Configuration class.
Pls, note the warning message in my application.properties [Spring Boot v2.0.0RELEASE, spring-cloud-starter-feign & spring-cloud-starter-ribbon v 1.4.3.RELEASE]
So what I did was to write a Configuration class as follows:
@Configuration
class LocalRibbonClientConfiguration {
@Bean
public ServerList<Server> ribbonServerList() {
// return new ConfigurationBasedServerList();
StaticServerList<Server> staticServerList = new StaticServerList<>((new Server("localhost", 8001)),
new Server("localhost", 8000));
return staticServerList;
}
}
Then, configured the Spring Boot Application to use this configuration as follows:
@SpringBootApplication
@EnableFeignClients("my-package.currencyconversionservice")
@RibbonClient(name = "currency-conversion-service", configuration = LocalRibbonClientConfiguration.class)
public class CurrencyConversionServiceApplication {
// nothing new here...
}
No need to change the Feign Proxy class. Posting just for this post to be served as a complete solution to the problem:
@FeignClient(name="currency-exchange-service")
@RibbonClient(name="currency-exchange-service")
public interface CurrencyExchangeServiceProxy {
@GetMapping("/currency-exchange/from/{from}/to/{to}")
public CurrencyConversionBean retrieveExchangeValue(@PathVariable("from") String from, @PathVariable("to") String to);
}
That's all. The problem was fixed.
Solution 4
I nearly wasted 2 hours to find the root cause. I mistakenly imported EnableEurekaClient in client application, which was the root cause for the issue. I finally resolved this issue by removing the import. To my surprise @EnableDiscoveryClient does not require the below dependency. But if you are using Eureka Naming server than this has to be used.
<dependency>
<groupId>org.springframework.cloud</groupId>
<artifactId>spring-cloud-starter-netflix-eureka-client</artifactId>
<version>2.0.0.RELEASE</version>
</dependency>
Solution 5
The problem is that your service doesn't know the host of the requested service. If you are using Eureka and zuul, put this line on your zuul .properties or .yml file :
eureka.client.fetch-registry=true
Author by
Yogen Rai
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Updated on January 30, 2022Comments
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Yogen Rai over 2 years
I'm trying to use Feign client. Below is my feing client:
import com.eprogrammerz.examples.domain.Movie; import org.springframework.cloud.netflix.feign.FeignClient; import org.springframework.web.bind.annotation.PathVariable; import org.springframework.web.bind.annotation.RequestMapping; import org.springframework.web.bind.annotation.RequestMethod; /** * Created by Yogen on 12/26/2016. */ @FeignClient(name = "movie-api") public interface MovieApi { @RequestMapping(method = RequestMethod.GET, value = "/movies/{id}") Movie getMovie(@PathVariable("id") Long id); }I'm calling it from simple service as below:
@Service public class MovieService { @Autowired MovieApi movieApi; public Movie findMovie(Long id){ Movie movieOfTheDay = movieApi.getMovie(id); return movieOfTheDay; } }My spring boot app is as below:
import org.springframework.boot.SpringApplication; import org.springframework.boot.autoconfigure.SpringBootApplication; import org.springframework.cloud.client.circuitbreaker.EnableCircuitBreaker; import org.springframework.cloud.netflix.feign.EnableFeignClients; @EnableFeignClients(basePackages = {"com.eprogrammerz.examples"}) @EnableCircuitBreaker @SpringBootApplication public class ClientAppApplication { public static void main(String[] args) { SpringApplication.run(ClientAppApplication.class, args); } }build.gradle
buildscript { ext { springBootVersion = '1.4.3.RELEASE' } repositories { jcenter() mavenCentral() } dependencies { classpath("org.springframework.boot:spring-boot-gradle-plugin:${springBootVersion}") } } apply plugin: 'java' apply plugin: 'eclipse' apply plugin: 'org.springframework.boot' jar { baseName = 'client-app' version = '0.0.1-SNAPSHOT' } sourceCompatibility = 1.8 targetCompatibility = 1.8 repositories { jcenter() mavenCentral() maven { url "https://repo.spring.io/snapshot" } maven { url "https://repo.spring.io/milestone" } } dependencies { compile('org.springframework.cloud:spring-cloud-starter-feign') // https://mvnrepository.com/artifact/com.netflix.hystrix/hystrix-core compile('org.springframework.cloud:spring-cloud-starter-hystrix') compile("org.springframework.boot:spring-boot-starter-web"){ exclude group: 'org.springframework.boot', module: 'spring-boot-starter-logging' } compileOnly('org.projectlombok:lombok') testCompile('org.springframework.boot:spring-boot-starter-test') } dependencyManagement { imports { mavenBom "org.springframework.cloud:spring-cloud-dependencies:Camden.BUILD-SNAPSHOT" mavenBom "org.springframework.boot:spring-boot-starter-parent:${springBootVersion}" } }I'm getting error as below:
2016-12-30 13:07:16.894 INFO 6748 --- [nio-8082-exec-1] o.s.web.servlet.DispatcherServlet : FrameworkServlet 'dispatcherServlet': initialization completed in 39 ms 2016-12-30 13:07:16.939 INFO 6748 --- [nio-8082-exec-1] c.e.e.controllers.RequestController : Calling findMovie(1203) 2016-12-30 13:07:17.240 INFO 6748 --- [rix-movie-api-1] s.c.a.AnnotationConfigApplicationContext : Refreshing org.springframework.context.annotation.AnnotationConfigApplicationContext@547496c2: startup date [Fri Dec 30 13:07:17 EST 2016]; parent: org.springframework.boot.context.embedded.AnnotationConfigEmbeddedWebApplicationContext@542e560f 2016-12-30 13:07:17.318 INFO 6748 --- [rix-movie-api-1] f.a.AutowiredAnnotationBeanPostProcessor : JSR-330 'javax.inject.Inject' annotation found and supported for autowiring 2016-12-30 13:07:17.619 INFO 6748 --- [rix-movie-api-1] c.netflix.config.ChainedDynamicProperty : Flipping property: movie-api.ribbon.ActiveConnectionsLimit to use NEXT property: niws.loadbalancer.availabilityFilteringRule.activeConnectionsLimit = 2147483647 2016-12-30 13:07:17.670 INFO 6748 --- [rix-movie-api-1] c.n.u.concurrent.ShutdownEnabledTimer : Shutdown hook installed for: NFLoadBalancer-PingTimer-movie-api 2016-12-30 13:07:17.727 INFO 6748 --- [rix-movie-api-1] c.netflix.loadbalancer.BaseLoadBalancer : Client:movie-api instantiated a LoadBalancer:DynamicServerListLoadBalancer:{NFLoadBalancer:name=movie-api,current list of Servers=[],Load balancer stats=Zone stats: {},Server stats: []}ServerList:null 2016-12-30 13:07:17.739 INFO 6748 --- [rix-movie-api-1] c.n.l.DynamicServerListLoadBalancer : Using serverListUpdater PollingServerListUpdater 2016-12-30 13:07:17.746 INFO 6748 --- [rix-movie-api-1] c.n.l.DynamicServerListLoadBalancer : DynamicServerListLoadBalancer for client movie-api initialized: DynamicServerListLoadBalancer:{NFLoadBalancer:name=movie-api,current list of Servers=[],Load balancer stats=Zone stats: {},Server stats: []}ServerList:com.netflix.loadbalancer.ConfigurationBasedServerList@45bcfd5 2016-12-30 13:07:18.191 ERROR 6748 --- [nio-8082-exec-1] o.a.c.c.C.[.[.[/].[dispatcherServlet] : Servlet.service() for servlet [dispatcherServlet] in context with path [] threw exception [Request processing failed; nested exception is com.netflix.hystrix.exception.HystrixRuntimeException: MovieApi#getMovie(Long) failed and no fallback available.] with root cause com.netflix.client.ClientException: Load balancer does not have available server for client: movie-api at com.netflix.loadbalancer.LoadBalancerContext.getServerFromLoadBalancer(LoadBalancerContext.java:468) ~[ribbon-loadbalancer-2.2.0.jar:2.2.0] at com.netflix.loadbalancer.reactive.LoadBalancerCommand$1.call(LoadBalancerCommand.java:184) ~[ribbon-loadbalancer-2.2.0.jar:2.2.0] at com.netflix.loadbalancer.reactive.LoadBalancerCommand$1.call(LoadBalancerCommand.java:180) ~[ribbon-loadbalancer-2.2.0.jar:2.2.0] at rx.Observable.unsafeSubscribe(Observable.java:10211) ~[rxjava-1.1.10.jar:1.1.10] at rx.internal.operators.OnSubscribeConcatMap.call(OnSubscribeConcatMap.java:94) ~[rxjava-1.1.10.jar:1.1.10] at rx.internal.operators.OnSubscribeConcatMap.call(OnSubscribeConcatMap.java:42) ~[rxjava-1.1.10.jar:1.1.10] at rx.Observable.unsafeSubscribe(Observable.java:10211) ~[rxjava-1.1.10.jar:1.1.10] at rx.internal.operators.OperatorRetryWithPredicate$SourceSubscriber$1.call(OperatorRetryWithPredicate.java:127) ~[rxjava-1.1.10.jar:1.1.10] at rx.internal.schedulers.TrampolineScheduler$InnerCurrentThreadScheduler.enqueue(TrampolineScheduler.java:73) ~[rxjava-1.1.10.jar:1.1.10] at rx.internal.schedulers.TrampolineScheduler$InnerCurrentThreadScheduler.schedule(TrampolineScheduler.java:52) ~[rxjava-1.1.10.jar:1.1.10] at rx.internal.operators.OperatorRetryWithPredicate$SourceSubscriber.onNext(OperatorRetryWithPredicate.java:79) ~[rxjava-1.1.10.jar:1.1.10] at rx.internal.operators.OperatorRetryWithPredicate$SourceSubscriber.onNext(OperatorRetryWithPredicate.java:45) ~[rxjava-1.1.10.jar:1.1.10] at rx.internal.util.ScalarSynchronousObservable$WeakSingleProducer.request(ScalarSynchronousObservable.java:276) ~[rxjava-1.1.10.jar:1.1.10] at rx.Subscriber.setProducer(Subscriber.java:209) ~[rxjava-1.1.10.jar:1.1.10] at rx.internal.util.ScalarSynchronousObservable$JustOnSubscribe.call(ScalarSynchronousObservable.java:138) ~[rxjava-1.1.10.jar:1.1.10] at rx.internal.util.ScalarSynchronousObservable$JustOnSubscribe.call(ScalarSynchronousObservable.java:129) ~[rxjava-1.1.10.jar:1.1.10] at rx.internal.operators.OnSubscribeLift.call(OnSubscribeLift.java:48) ~[rxjava-1.1.10.jar:1.1.10] at rx.internal.operators.OnSubscribeLift.call(OnSubscribeLift.java:30) ~[rxjava-1.1.10.jar:1.1.10] at rx.internal.operators.OnSubscribeLift.call(OnSubscribeLift.java:48) ~[rxjava-1.1.10.jar:1.1.10] at rx.internal.operators.OnSubscribeLift.call(OnSubscribeLift.java:30) ~[rxjava-1.1.10.jar:1.1.10] at rx.internal.operators.OnSubscribeLift.call(OnSubscribeLift.java:48) ~[rxjava-1.1.10.jar:1.1.10] at rx.internal.operators.OnSubscribeLift.call(OnSubscribeLift.java:30) ~[rxjava-1.1.10.jar:1.1.10] at rx.Observable.subscribe(Observable.java:10307) ~[rxjava-1.1.10.jar:1.1.10] at rx.Observable.subscribe(Observable.java:10274) ~[rxjava-1.1.10.jar:1.1.10] at rx.observables.BlockingObservable.blockForSingle(BlockingObservable.java:445) ~[rxjava-1.1.10.jar:1.1.10] at rx.observables.BlockingObservable.single(BlockingObservable.java:342) ~[rxjava-1.1.10.jar:1.1.10] at com.netflix.client.AbstractLoadBalancerAwareClient.executeWithLoadBalancer(AbstractLoadBalancerAwareClient.java:102) ~[ribbon-loadbalancer-2.2.0.jar:2.2.0] at org.springframework.cloud.netflix.feign.ribbon.LoadBalancerFeignClient.execute(LoadBalancerFeignClient.java:63) ~[spring-cloud-netflix-core-1.2.4.BUILD-SNAPSHOT.jar:1.2.4.BUILD-SNAPSHOT] at feign.SynchronousMethodHandler.executeAndDecode(SynchronousMethodHandler.java:97) ~[feign-core-9.3.1.jar:na] at feign.SynchronousMethodHandler.invoke(SynchronousMethodHandler.java:76) ~[feign-core-9.3.1.jar:na] at feign.hystrix.HystrixInvocationHandler$1.run(HystrixInvocationHandler.java:108) ~[feign-hystrix-9.3.1.jar:na] at com.netflix.hystrix.HystrixCommand$2.call(HystrixCommand.java:301) ~[hystrix-core-1.5.6.jar:1.5.6] at com.netflix.hystrix.HystrixCommand$2.call(HystrixCommand.java:297) ~[hystrix-core-1.5.6.jar:1.5.6] at rx.internal.operators.OnSubscribeDefer.call(OnSubscribeDefer.java:46) ~[rxjava-1.1.10.jar:1.1.10] at rx.internal.operators.OnSubscribeDefer.call(OnSubscribeDefer.java:35) ~[rxjava-1.1.10.jar:1.1.10] at rx.internal.operators.OnSubscribeLift.call(OnSubscribeLift.java:48) ~[rxjava-1.1.10.jar:1.1.10] at rx.internal.operators.OnSubscribeLift.call(OnSubscribeLift.java:30) ~[rxjava-1.1.10.jar:1.1.10] at rx.internal.operators.OnSubscribeLift.call(OnSubscribeLift.java:48) ~[rxjava-1.1.10.jar:1.1.10] at rx.internal.operators.OnSubscribeLift.call(OnSubscribeLift.java:30) ~[rxjava-1.1.10.jar:1.1.10] at rx.internal.operators.OnSubscribeLift.call(OnSubscribeLift.java:48) ~[rxjava-1.1.10.jar:1.1.10] at rx.internal.operators.OnSubscribeLift.call(OnSubscribeLift.java:30) ~[rxjava-1.1.10.jar:1.1.10] at rx.Observable.unsafeSubscribe(Observable.java:10211) ~[rxjava-1.1.10.jar:1.1.10] at rx.internal.operators.OnSubscribeDefer.call(OnSubscribeDefer.java:51) ~[rxjava-1.1.10.jar:1.1.10] at rx.internal.operators.OnSubscribeDefer.call(OnSubscribeDefer.java:35) ~[rxjava-1.1.10.jar:1.1.10] at rx.Observable.unsafeSubscribe(Observable.java:10211) ~[rxjava-1.1.10.jar:1.1.10] at rx.internal.operators.OnSubscribeDoOnEach.call(OnSubscribeDoOnEach.java:41) ~[rxjava-1.1.10.jar:1.1.10] at rx.internal.operators.OnSubscribeDoOnEach.call(OnSubscribeDoOnEach.java:30) ~[rxjava-1.1.10.jar:1.1.10] at rx.internal.operators.OnSubscribeLift.call(OnSubscribeLift.java:48) ~[rxjava-1.1.10.jar:1.1.10] at rx.internal.operators.OnSubscribeLift.call(OnSubscribeLift.java:30) ~[rxjava-1.1.10.jar:1.1.10] at rx.Observable.unsafeSubscribe(Observable.java:10211) ~[rxjava-1.1.10.jar:1.1.10] at rx.internal.operators.OperatorSubscribeOn$1.call(OperatorSubscribeOn.java:94) ~[rxjava-1.1.10.jar:1.1.10] at com.netflix.hystrix.strategy.concurrency.HystrixContexSchedulerAction$1.call(HystrixContexSchedulerAction.java:56) ~[hystrix-core-1.5.6.jar:1.5.6] at com.netflix.hystrix.strategy.concurrency.HystrixContexSchedulerAction$1.call(HystrixContexSchedulerAction.java:47) ~[hystrix-core-1.5.6.jar:1.5.6] at com.netflix.hystrix.strategy.concurrency.HystrixContexSchedulerAction.call(HystrixContexSchedulerAction.java:69) ~[hystrix-core-1.5.6.jar:1.5.6] at rx.internal.schedulers.ScheduledAction.run(ScheduledAction.java:55) ~[rxjava-1.1.10.jar:1.1.10] at java.util.concurrent.Executors$RunnableAdapter.call(Executors.java:511) ~[na:1.8.0_51] at java.util.concurrent.FutureTask.run(FutureTask.java:266) ~[na:1.8.0_51] at java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1142) ~[na:1.8.0_51] at java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:617) ~[na:1.8.0_51] at java.lang.Thread.run(Thread.java:745) [na:1.8.0_51]I tried different way. But couldn't figure out the solution. I couldn't find any information about this on Spring Cloud Netflix too. I couldn't find any information on discussion thread on StackOverflow too.
What I'm missing here? TIA.
Further Details:
application.yml for movie-api microservice is as below:
server: port: 8090 logging: config: classpath:log4j2.yml spring: application: name: movie-apiSpring boot app on movie-api module:
@SpringBootApplication public class MovieApiApplication { public static void main(String[] args) { SpringApplication.run(MovieApiApplication.class, args); } }And controller is as below:
@RestController @Slf4j public class MovieController { @Autowired private MovieRepository movieRepository; @RequestMapping("/movies/{id}") public ResponseEntity<Movie> getBook(@PathVariable("id") Long id){ log.trace("getBook({})",id); Optional<Movie> movie = Optional.of(movieRepository.findOneById(id)); if(movie.isPresent()) return new ResponseEntity(movie.get(), HttpStatus.OK); return new ResponseEntity<Movie>(HttpStatus.NOT_FOUND); } }