dubbo调用提供者接口报错

Question

 HTTP Status 500 - Request processing failed; nested exception is com.alibaba.dubbo.rpc.RpcException: Failed to invoke the method sayHello in the service com.soecode.dubbo.service.HelloService. Tried 3 times of the providers [192.168.63.47:20880] (1/1) from the registry 192.168.63.47:2181 on the consumer 192.168.63.47 using the dubbo version 2.4.10. Last error is: Failed to invoke remote method: sayHello, provider: dubbo://192.168.63.47:20880/com.soecode.dubbo.service.HelloService?anyhost=true&application=demo-consumer&check=false&default.accepts=1&dubbo=2.4.10&executes=1&interface=com.soecode.dubbo.service.HelloService&methods=sayHello&pid=1348&revision=dubbo.provider&sayHello.actives=1&side=consumer&timestamp=1510110717473, cause: com.alibaba.dubbo.rpc.RpcException: Failed to invoke method sayHello in provider dubbo://192.168.63.47:20880/com.soecode.dubbo.service.HelloService?anyhost=true&application=demo-provider&default.accepts=1&dubbo=2.4.10&executes=1&interface=com.soecode.dubbo.service.HelloService&methods=sayHello&pid=9668&side=provider&timestamp=1510110709853, cause: The service using threads greater than <dubbo:service executes="1" /> limited.

初学dubbo，写了一个下载文件的接口，消费者调用提供者的时候就报这个错，文件也下载下来了，但是一直报这个错！
求大神指教！

Answer 1

你那几个类实现序列化接口