same code with spring boot version 1.3.8.RELEASE and cloud version 'Brixton.SR' works right. but '1.5.2.RELEASE' and 'Dalston.RC1' not work.
exception
HTTP Status 500 - Request processing failed; nested exception is java.lang.RuntimeException: com.netflix.client.ClientException: Load balancer does not have available server for client: math-service
OK, you can add the following to your application.properties, then it works.
feign.hystrix.enabled=true
See Dalston Release note and Disable HystrixCommands For FeignClients By Default, Feign clients no longer wrap methods in Hystrix commands by default . You must have Hystrix on the classpath and also set feign.hystrix.enabled=true to have Feign automatically wrap methods in Hystrix commands.