Zuul with oauth2 client getting "Load balancer does not have available server for client" error

[lhwong]

I have one UI server (as gateway to resource server), one auth server and multiple resource servers.

The UI server is configured as oauth2 client. When using configure Zuul using zuul: routes: serviceId, I got the following exception. zuul: routes: url works fine.

com.netflix.zuul.exception.ZuulException: Forwarding error
    at org.springframework.cloud.netflix.zuul.filters.route.RibbonRoutingFilter.handleException(RibbonRoutingFilter.java:183) ~[spring-cloud-netflix-core-1.3.1.RELEASE.jar:1.3.1.RELEASE]
    at org.springframework.cloud.netflix.zuul.filters.route.RibbonRoutingFilter.forward(RibbonRoutingFilter.java:158) ~[spring-cloud-netflix-core-1.3.1.RELEASE.jar:1.3.1.RELEASE]
    at org.springframework.cloud.netflix.zuul.filters.route.RibbonRoutingFilter.run(RibbonRoutingFilter.java:106) ~[spring-cloud-netflix-core-1.3.1.RELEASE.jar:1.3.1.RELEASE]
    at com.netflix.zuul.ZuulFilter.runFilter(ZuulFilter.java:112) ~[zuul-core-1.3.0.jar:1.3.0]
    at com.netflix.zuul.FilterProcessor.processZuulFilter(FilterProcessor.java:193) ~[zuul-core-1.3.0.jar:1.3.0]
    at com.netflix.zuul.FilterProcessor.runFilters(FilterProcessor.java:157) ~[zuul-core-1.3.0.jar:1.3.0]
    at com.netflix.zuul.FilterProcessor.route(FilterProcessor.java:118) ~[zuul-core-1.3.0.jar:1.3.0]
    at com.netflix.zuul.ZuulRunner.route(ZuulRunner.java:96) ~[zuul-core-1.3.0.jar:1.3.0]
    at com.netflix.zuul.http.ZuulServlet.route(ZuulServlet.java:116) ~[zuul-core-1.3.0.jar:1.3.0]
    at com.netflix.zuul.http.ZuulServlet.service(ZuulServlet.java:81) ~[zuul-core-1.3.0.jar:1.3.0]
    at 
Caused by: com.netflix.client.ClientException: Load balancer does not have available server for client: api
    at com.netflix.loadbalancer.LoadBalancerContext.getServerFromLoadBalancer(LoadBalancerContext.java:483) ~[ribbon-loadbalancer-2.2.2.jar:2.2.2]
    at com.netflix.loadbalancer.reactive.LoadBalancerCommand$1.call(LoadBalancerCommand.java:184) ~[ribbon-loadbalancer-2.2.2.jar:2.2.2]
    at com.netflix.loadbalancer.reactive.LoadBalancerCommand$1.call(LoadBalancerCommand.java:180) ~[ribbon-loadbalancer-2.2.2.jar:2.2.2]
    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-

...

    at rx.observables.BlockingObservable.toFuture(BlockingObservable.java:412) ~[rxjava-1.1.10.jar:1.1.10]
    at com.netflix.hystrix.HystrixCommand.queue(HystrixCommand.java:378) ~[hystrix-core-1.5.12.jar:1.5.12]
    at com.netflix.hystrix.HystrixCommand.execute(HystrixCommand.java:344) ~[hystrix-core-1.5.12.jar:1.5.12]
    at org.springframework.cloud.netflix.zuul.filters.route.RibbonRoutingFilter.forward(RibbonRoutingFilter.java:152) ~[spring-cloud-netflix-core-1.3.1.RELEASE.jar:1.3.1.RELEASE]
    ... 117 common frames omitted

Below is the configuration for my UI server.

security:
  user:
    password: none
  oauth2:
    client:
      accessTokenUri: http://localhost:9999/uaa/oauth/token
      userAuthorizationUri: http://localhost:9999/uaa/oauth/authorize
      userImpersonationUri: http://localhost:9999/uaa/oauth/impersonate
      clientId: acme
      clientSecret: acmesecret
    resource:
      jwt:
        keyValue: |
          -----BEGIN PUBLIC KEY-----
                    -----END PUBLIC KEY-----

zuul:
  routes:
    resource:
      path: /resource/**
      url: http://localhost:9000/resource
    api:
      path: /api/**
      serviceId: api

eureka:
  instance:
    leaseRenewalIntervalInSeconds: 1
    leaseExpirationDurationInSeconds: 1
    metadataMap:
      instanceId: ${vcap.application.instance_id:${spring.application.name}:${spring.application.instance_id:${random.value}}}
  client:
    # Default values comes from org.springframework.cloud.netflix.eurek.EurekaClientConfigBean
    registryFetchIntervalSeconds: 1
    instanceInfoReplicationIntervalSeconds: 1
    initialInstanceInfoReplicationIntervalSeconds: 1

# Discovery Server Access

    serviceUrl:
      defaultZone: http://localhost:8761/eureka/

ribbon:

# FelFelFel: 1000
# capital or not capital, that is the question...

  # Interval to refresh the server list from the source
  serverListRefreshInterval: 1000

  # Max number of retries on the same server (excluding the first try)
  maxAutoRetries: 1

  # Max number of next servers to retry (excluding the first server)
  maxAutoRetriesNextServer: 1

  # Interval to refresh the server list from the source
  ServerListRefreshInterval: 1000

  # Max number of retries on the same server (excluding the first try)
  MaxAutoRetries: 1

  # Max number of next servers to retry (excluding the first server)
  MaxAutoRetriesNextServer: 1

I believe this issue is same as #1770. It has been closed, hence, I create a new issue here.

[lhwong]

Fixed by adding spring-cloud-starter-eureka dependency