<ul class="contains-task-list">
<li class="task-list-item"><input type="checkbox" id="" disabled="" class="task-list-item-checkbox"> I have searched the <a href="https://github.com/apache/dubbo/issues">issues</a> of this repository and believe that this is not a duplicate.</li>
<li class="task-list-item"><input type="checkbox" id="" disabled="" class="task-list-item-checkbox"> I have checked the <a href="https://github.com/apache/dubbo/blob/master/FAQ.md">FAQ</a> of this repository and believe that this is not a duplicate.</li>
</ul>
<h3 dir="auto">Environment</h3>
<ul dir="auto">
<li>Dubbo version: 2.7.4</li>
<li>Operating System version: Mac</li>
<li>Java version: 1.8</li>
</ul>
<h3 dir="auto">Steps to reproduce this issue</h3>
<ol dir="auto">
<li>import the source code of dubbo.</li>
<li>at root of the dubbo, execute mvn install</li>
<li>run zookeeper at localhost:2181</li>
<li>cd to dubbo-demo/dubbo-demo-api/dubbo-demo-api-provide/src/......  run main()</li>
<li>has error No such extension org.apache.dubbo.configcenter.DynamicConfigurationFactory by name zookeeper</li>
</ol>
<p dir="auto">i want to run this demo at local.</p>
<ul class="contains-task-list">
<li class="task-list-item"><input type="checkbox" id="" disabled="" class="task-list-item-checkbox" checked=""> I have searched the <a href="https://github.com/apache/incubator-dubbo/issues">issues</a> of this repository and believe that this is not a duplicate.</li>
<li class="task-list-item"><input type="checkbox" id="" disabled="" class="task-list-item-checkbox" checked=""> I have checked the <a href="https://github.com/apache/incubator-dubbo/blob/master/FAQ.md">FAQ</a> of this repository and believe that this is not a duplicate.</li>
</ul>
<h3 dir="auto">Environment</h3>
<ul dir="auto">
<li>Dubbo version: 2.5.4</li>
<li>Operating System version: linux</li>
<li>Java version: 1.8</li>
</ul>
<h3 dir="auto">Steps to reproduce this issue</h3>
<ol dir="auto">
<li>many request once time</li>
</ol>
<p dir="auto">6000, group=smart}]], channel: /172.16.31.191:44814 -&gt; /172.16.21.41:20835<br>
at com.alibaba.dubbo.rpc.cluster.support.FailoverClusterInvoker.doInvoke(FailoverClusterInvoker.java:101)<br>
at com.alibaba.dubbo.rpc.cluster.support.AbstractClusterInvoker.invoke(AbstractClusterInvoker.java:227)<br>
at com.alibaba.dubbo.rpc.cluster.support.wrapper.MockClusterInvoker.invoke(MockClusterInvoker.java:72)<br>
at com.alibaba.dubbo.rpc.proxy.InvokerInvocationHandler.invoke(InvokerInvocationHandler.java:52)<br>
at com.alibaba.dubbo.common.bytecode.proxy1.getUserBySession(proxy1.java)<br>
at<br>
Caused by: com.alibaba.dubbo.remoting.TimeoutException: Sending request timeout in client-side by scan timer. start time: 2019-01-26 00:02:04.295, end time: 2019-01-26 00:02:10.301, elapsed: 6006 ms, timeout: 6000 ms, request: Request [id=258487922, version=2.0.0, twoway=true, event=false, broken=false, data=RpcInvocation<br>
at com.alibaba.dubbo.remoting.exchange.support.DefaultFuture.returnFromResponse(DefaultFuture.java:188)<br>
at com.alibaba.dubbo.remoting.exchange.support.DefaultFuture.get(DefaultFuture.java:110)<br>
at com.alibaba.dubbo.remoting.exchange.support.DefaultFuture.get(DefaultFuture.java:84)<br>
at com.alibaba.dubbo.rpc.protocol.dubbo.DubboInvoker.doInvoke(DubboInvoker.java:96)<br>
at com.alibaba.dubbo.rpc.protocol.AbstractInvoker.invoke(AbstractInvoker.java:144)<br>
at com.tuya.basic.dubbo.ext.filter.ServiceDegradationFilter.invoke(ServiceDegradationFilter.java:44)<br>
at com.alibaba.dubbo.rpc.protocol.ProtocolFilterWrapper$1.invoke(ProtocolFilterWrapper.java:91)<br>
at com.alibaba.csp.sentinel.adapter.dubbo.DubboAppContextFilter.invoke(DubboAppContextFilter.java:41)<br>
at com.alibaba.dubbo.rpc.protocol.ProtocolFilterWrapper$1.invoke(ProtocolFilterWrapper.java:91)<br>
at com.alibaba.csp.sentinel.adapter.dubbo.SentinelDubboConsumerFilter.invoke(SentinelDubboConsumerFilter.java:60)<br>
at com.alibaba.dubbo.rpc.protocol.ProtocolFilterWrapper$1.invoke(ProtocolFilterWrapper.java:91)<br>
at com.alibaba.dubbo.monitor.support.MonitorFilter.invoke(MonitorFilter.java:75)<br>
at com.alibaba.dubbo.rpc.protocol.ProtocolFilterWrapper$1.invoke(ProtocolFilterWrapper.java:91)<br>
at com.alibaba.dubbo.rpc.protocol.dubbo.filter.FutureFilter.invoke(FutureFilter.java:53)<br>
at com.alibaba.dubbo.rpc.protocol.ProtocolFilterWrapper$1.invoke(ProtocolFilterWrapper.java:91)<br>
at com.alibaba.dubbo.rpc.filter.ConsumerContextFilter.invoke(ConsumerContextFilter.java:48)<br>
at com.alibaba.dubbo.rpc.protocol.ProtocolFilterWrapper$1.invoke(ProtocolFilterWrapper.java:91)<br>
at com.alibaba.dubbo.rpc.listener.ListenerInvokerWrapper.invoke(ListenerInvokerWrapper.java:74)<br>
at com.alibaba.dubbo.rpc.protocol.InvokerWrapper.invoke(InvokerWrapper.java:53)<br>
at com.alibaba.dubbo.rpc.cluster.support.FailoverClusterInvoker.doInvoke(FailoverClusterInvoker.java:77)<br>
... 39 common frames omitted</p>
<p dir="auto">什么原因会导致TimeoutException: Sending request timeout in client-side by scan timer异常</p>