客户端错误：
com.alibaba.dubbo.rpc.RpcException: Invoke remote method timeout. method: searchUser, provider:
...
cause: Waiting server-side response timeout by scan timer. start time: 2018-08-11 14:46:49.979, end time: 2018-08-11 14:46:51.002, client elapsed: 44 ms, server elapsed: 959 ms, timeout: 1000 ms, request: Request
...服务端警告：
2015-06-17 14:46:52,454 WARN [DubboServerHandler-192.168.25.129:2181-thread-2] (ChannelEventRunnable.java:84) - [DUBBO] ChannelEventRunnable handle RECEIVED operation error
com.alibaba.dubbo.remoting.RemotingException: Failed to send message Response [id=0, version=2.0.0, status=20, event=false, error=null, result=RpcResult [result=com.ceair.cesso.dto.SearchUserResult@7ba2a1d2, exception=null]] to /172.25.3.91:50849, cause: null
at com.alibaba.dubbo.remoting.transport.netty.NettyChannel.send(NettyChannel.java:108)
at com.alibaba.dubbo.remoting.transport.AbstractPeer.send(AbstractPeer.java:51)
at com.alibaba.dubbo.remoting.exchange.support.header.HeaderExchangeHandler.received(HeaderExchangeHandler.java:171)
at com.alibaba.dubbo.remoting.transport.DecodeHandler.received(DecodeHandler.java:52)
at com.alibaba.dubbo.remoting.transport.dispatcher.ChannelEventRunnable.run(ChannelEventRunnable.java:82)
at java.util.concurrent.ThreadPoolExecutor$Worker.runTask(ThreadPoolExecutor.java:886)
at java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:908)
at java.lang.Thread.run(Thread.java:662)
Caused by: java.nio.channels.ClosedChannelException
at org.jboss.netty.channel.socket.nio.NioWorker.cleanUpWriteBuffer(NioWorker.java:643)
at org.jboss.netty.channel.socket.nio.NioWorker.writeFromUserCode(NioWorker.java:370)
at org.jboss.netty.channel.socket.nio.NioServerSocketPipelineSink.handleAcceptedSocket(NioServerSocketPipelineSink.java:137)
at org.jboss.netty.channel.socket.nio.NioServerSocketPipelineSink.eventSunk(NioServerSocketPipelineSink.java:76)
at org.jboss.netty.channel.Channels.write(Channels.java:632)
at org.jboss.netty.handler.codec.oneone.OneToOneEncoder.handleDownstream(OneToOneEncoder.java:70)
at com.alibaba.dubbo.remoting.transport.netty.NettyHandler.writeRequested(NettyHandler.java:99)
at org.jboss.netty.channel.Channels.write(Channels.java:611)
at org.jboss.netty.channel.Channels.write(Channels.java:578)
at org.jboss.netty.channel.AbstractChannel.write(AbstractChannel.java:251)
at com.alibaba.dubbo.remoting.transport.netty.NettyChannel.send(NettyChannel.java:98)
... 7 more原因分析
客户端日志可以看到是超时错误。(正在进行调试）
接着给出信息：客户端、服务端花费的时间；
在看服务端，是通道被关闭，无法发送信息。
整体看起来，就是超时了，客户端没有得到返回信息，服务端不能发送信息。
检查客户端、服务端的超时配置；发现客户端的超时时间没有设置，设置为一个较长时间，就可以了。
<!-- 超时单位为毫秒 -->
<dubbo:reference interface="cn.e3mall.content.service.ContentService" id="contentService" timeout="1200000"></dubbo:reference>