<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/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"> 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: 2.5.2(test)，but there are many different versions inside the company.</li>
</ul>
<div class="snippet-clipboard-content notranslate position-relative overflow-auto" data-snippet-clipboard-copy-content="     &lt;dependency&gt;
            &lt;groupId&gt;com.alibaba&lt;/groupId&gt;
            &lt;artifactId&gt;dubbo&lt;/artifactId&gt;
            &lt;version&gt;2.5.2&lt;/version&gt;
            &lt;exclusions&gt;
                &lt;exclusion&gt;
                    &lt;artifactId&gt;javassist&lt;/artifactId&gt;
                    &lt;groupId&gt;org.javassist&lt;/groupId&gt;
                &lt;/exclusion&gt;
            &lt;/exclusions&gt;
        &lt;/dependency&gt;"><pre class="notranslate"><code class="notranslate">     &lt;dependency&gt;
            &lt;groupId&gt;com.alibaba&lt;/groupId&gt;
            &lt;artifactId&gt;dubbo&lt;/artifactId&gt;
            &lt;version&gt;2.5.2&lt;/version&gt;
            &lt;exclusions&gt;
                &lt;exclusion&gt;
                    &lt;artifactId&gt;javassist&lt;/artifactId&gt;
                    &lt;groupId&gt;org.javassist&lt;/groupId&gt;
                &lt;/exclusion&gt;
            &lt;/exclusions&gt;
        &lt;/dependency&gt;
</code></pre></div>
<ul dir="auto">
<li>Operating System version: <code class="notranslate">uname -a</code></li>
</ul>
<div class="snippet-clipboard-content notranslate position-relative overflow-auto" data-snippet-clipboard-copy-content="Darwin tes.local 17.7.0 Darwin Kernel Version 17.7.0: Thu Jun 21 22:53:14 PDT 2018; root:xnu-4570.71.2~1/RELEASE_X86_64 x86_64"><pre class="notranslate"><code class="notranslate">Darwin tes.local 17.7.0 Darwin Kernel Version 17.7.0: Thu Jun 21 22:53:14 PDT 2018; root:xnu-4570.71.2~1/RELEASE_X86_64 x86_64
</code></pre></div>
<ul dir="auto">
<li>Java version: java -version ，but there are many different versions（1.6，1.7） inside the company.</li>
</ul>
<div class="snippet-clipboard-content notranslate position-relative overflow-auto" data-snippet-clipboard-copy-content="java version &quot;1.8.0_161&quot;
Java(TM) SE Runtime Environment (build 1.8.0_161-b12)
Java HotSpot(TM) 64-Bit Server VM (build 25.161-b12, mixed mode)"><pre class="notranslate"><code class="notranslate">java version "1.8.0_161"
Java(TM) SE Runtime Environment (build 1.8.0_161-b12)
Java HotSpot(TM) 64-Bit Server VM (build 25.161-b12, mixed mode)
</code></pre></div>
<h3 dir="auto">Reason</h3>
<p dir="auto">The low version of dubbo does not provide elegant closure of the dubbo service network, so we are compatible with reflection, but now we don't know the number of consumers.</p>
<p dir="auto">i can get provider bu using reflect,but can't get consumer. Thanks in advance. please<br>
forgive my lame English</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: 2.7.0</li>
<li>Operating System version: macOS Mojave 10.14.3 18D42 x86_64</li>
<li>Java version: 1.8.0_202</li>
</ul>
<h3 dir="auto">Steps to reproduce this issue</h3>
<ol dir="auto">
<li>boot (<a href="https://github.com/guxingke/demo/blob/master/dubbo-demo/p2p-group-bug-demo/src/main/java/com/gxk/demo/boot/BugServerApp.java">https://github.com/guxingke/demo/blob/master/dubbo-demo/p2p-group-bug-demo/src/main/java/com/gxk/demo/boot/BugServerApp.java</a>)</li>
<li>boot (<a href="https://github.com/guxingke/demo/blob/master/dubbo-demo/p2p-group-bug-demo/src/main/java/com/gxk/demo/boot/ClientApp.java">https://github.com/guxingke/demo/blob/master/dubbo-demo/p2p-group-bug-demo/src/main/java/com/gxk/demo/boot/ClientApp.java</a>)</li>
</ol>
<h3 dir="auto">Expected Result</h3>
<p dir="auto">like "Hello dubbo, response from provider: 192.168.136.176:52159"</p>
<h3 dir="auto">Actual Result</h3>
<p dir="auto">nothing, but exception.</p>
<p dir="auto">If there is an exception, please attach the exception trace:</p>
<div class="snippet-clipboard-content notranslate position-relative overflow-auto" data-snippet-clipboard-copy-content="[NettyServerWorker-3-1] INFO org.apache.dubbo.rpc.protocol.dubbo.CallbackServiceCodec -  [DUBBO] Not found exported service: com.gxk.demo.service.HelloService:20880 in [test/com.gxk.demo.service.HelloService:20880], may be version or group mismatch , channel: consumer: /192.168.136.176:51666 --&gt; provider: /192.168.136.176:20880, message:RpcInvocation [methodName=hello, parameterTypes=[class java.lang.String], arguments=null, attachments={path=com.gxk.demo.service.HelloService, dubbo=2.0.2, interface=com.gxk.demo.service.HelloService, version=0.0.0}], dubbo version: 2.7.0, current host: 192.168.136.176
org.apache.dubbo.remoting.RemotingException: Not found exported service: com.gxk.demo.service.HelloService:20880 in [test/com.gxk.demo.service.HelloService:20880], may be version or group mismatch , channel: consumer: /192.168.136.176:51666 --&gt; provider: /192.168.136.176:20880, message:RpcInvocation [methodName=hello, parameterTypes=[class java.lang.String], arguments=null, attachments={path=com.gxk.demo.service.HelloService, dubbo=2.0.2, interface=com.gxk.demo.service.HelloService, version=0.0.0}]
	at org.apache.dubbo.rpc.protocol.dubbo.DubboProtocol.getInvoker(DubboProtocol.java:223)
	at org.apache.dubbo.rpc.protocol.dubbo.CallbackServiceCodec.decodeInvocationArgument(CallbackServiceCodec.java:270)
	at org.apache.dubbo.rpc.protocol.dubbo.DecodeableRpcInvocation.decode(DecodeableRpcInvocation.java:134)
	at org.apache.dubbo.rpc.protocol.dubbo.DecodeableRpcInvocation.decode(DecodeableRpcInvocation.java:70)
	at org.apache.dubbo.rpc.protocol.dubbo.DubboCodec.decodeBody(DubboCodec.java:132)
	at org.apache.dubbo.remoting.exchange.codec.ExchangeCodec.decode(ExchangeCodec.java:125)
	at org.apache.dubbo.remoting.exchange.codec.ExchangeCodec.decode(ExchangeCodec.java:85)
	at org.apache.dubbo.rpc.protocol.dubbo.DubboCountCodec.decode(DubboCountCodec.java:46)
	at org.apache.dubbo.remoting.transport.netty4.NettyCodecAdapter$InternalDecoder.decode(NettyCodecAdapter.java:95)
	at io.netty.handler.codec.ByteToMessageDecoder.decodeRemovalReentryProtection(ByteToMessageDecoder.java:489)
	at io.netty.handler.codec.ByteToMessageDecoder.callDecode(ByteToMessageDecoder.java:428)
	at io.netty.handler.codec.ByteToMessageDecoder.channelRead(ByteToMessageDecoder.java:265)
	at io.netty.channel.AbstractChannelHandlerContext.invokeChannelRead(AbstractChannelHandlerContext.java:362)
	at io.netty.channel.AbstractChannelHandlerContext.invokeChannelRead(AbstractChannelHandlerContext.java:348)
	at io.netty.channel.AbstractChannelHandlerContext.fireChannelRead(AbstractChannelHandlerContext.java:340)
	at io.netty.channel.DefaultChannelPipeline$HeadContext.channelRead(DefaultChannelPipeline.java:1434)
	at io.netty.channel.AbstractChannelHandlerContext.invokeChannelRead(AbstractChannelHandlerContext.java:362)
	at io.netty.channel.AbstractChannelHandlerContext.invokeChannelRead(AbstractChannelHandlerContext.java:348)
	at io.netty.channel.DefaultChannelPipeline.fireChannelRead(DefaultChannelPipeline.java:965)
	at io.netty.channel.nio.AbstractNioByteChannel$NioByteUnsafe.read(AbstractNioByteChannel.java:163)
	at io.netty.channel.nio.NioEventLoop.processSelectedKey(NioEventLoop.java:647)
	at io.netty.channel.nio.NioEventLoop.processSelectedKeysOptimized(NioEventLoop.java:582)
	at io.netty.channel.nio.NioEventLoop.processSelectedKeys(NioEventLoop.java:499)
	at io.netty.channel.nio.NioEventLoop.run(NioEventLoop.java:461)
	at io.netty.util.concurrent.SingleThreadEventExecutor$5.run(SingleThreadEventExecutor.java:884)
	at io.netty.util.concurrent.FastThreadLocalRunnable.run(FastThreadLocalRunnable.java:30)
	at java.lang.Thread.run(Thread.java:748)"><pre class="notranslate"><code class="notranslate">[NettyServerWorker-3-1] INFO org.apache.dubbo.rpc.protocol.dubbo.CallbackServiceCodec -  [DUBBO] Not found exported service: com.gxk.demo.service.HelloService:20880 in [test/com.gxk.demo.service.HelloService:20880], may be version or group mismatch , channel: consumer: /192.168.136.176:51666 --&gt; provider: /192.168.136.176:20880, message:RpcInvocation [methodName=hello, parameterTypes=[class java.lang.String], arguments=null, attachments={path=com.gxk.demo.service.HelloService, dubbo=2.0.2, interface=com.gxk.demo.service.HelloService, version=0.0.0}], dubbo version: 2.7.0, current host: 192.168.136.176
org.apache.dubbo.remoting.RemotingException: Not found exported service: com.gxk.demo.service.HelloService:20880 in [test/com.gxk.demo.service.HelloService:20880], may be version or group mismatch , channel: consumer: /192.168.136.176:51666 --&gt; provider: /192.168.136.176:20880, message:RpcInvocation [methodName=hello, parameterTypes=[class java.lang.String], arguments=null, attachments={path=com.gxk.demo.service.HelloService, dubbo=2.0.2, interface=com.gxk.demo.service.HelloService, version=0.0.0}]
	at org.apache.dubbo.rpc.protocol.dubbo.DubboProtocol.getInvoker(DubboProtocol.java:223)
	at org.apache.dubbo.rpc.protocol.dubbo.CallbackServiceCodec.decodeInvocationArgument(CallbackServiceCodec.java:270)
	at org.apache.dubbo.rpc.protocol.dubbo.DecodeableRpcInvocation.decode(DecodeableRpcInvocation.java:134)
	at org.apache.dubbo.rpc.protocol.dubbo.DecodeableRpcInvocation.decode(DecodeableRpcInvocation.java:70)
	at org.apache.dubbo.rpc.protocol.dubbo.DubboCodec.decodeBody(DubboCodec.java:132)
	at org.apache.dubbo.remoting.exchange.codec.ExchangeCodec.decode(ExchangeCodec.java:125)
	at org.apache.dubbo.remoting.exchange.codec.ExchangeCodec.decode(ExchangeCodec.java:85)
	at org.apache.dubbo.rpc.protocol.dubbo.DubboCountCodec.decode(DubboCountCodec.java:46)
	at org.apache.dubbo.remoting.transport.netty4.NettyCodecAdapter$InternalDecoder.decode(NettyCodecAdapter.java:95)
	at io.netty.handler.codec.ByteToMessageDecoder.decodeRemovalReentryProtection(ByteToMessageDecoder.java:489)
	at io.netty.handler.codec.ByteToMessageDecoder.callDecode(ByteToMessageDecoder.java:428)
	at io.netty.handler.codec.ByteToMessageDecoder.channelRead(ByteToMessageDecoder.java:265)
	at io.netty.channel.AbstractChannelHandlerContext.invokeChannelRead(AbstractChannelHandlerContext.java:362)
	at io.netty.channel.AbstractChannelHandlerContext.invokeChannelRead(AbstractChannelHandlerContext.java:348)
	at io.netty.channel.AbstractChannelHandlerContext.fireChannelRead(AbstractChannelHandlerContext.java:340)
	at io.netty.channel.DefaultChannelPipeline$HeadContext.channelRead(DefaultChannelPipeline.java:1434)
	at io.netty.channel.AbstractChannelHandlerContext.invokeChannelRead(AbstractChannelHandlerContext.java:362)
	at io.netty.channel.AbstractChannelHandlerContext.invokeChannelRead(AbstractChannelHandlerContext.java:348)
	at io.netty.channel.DefaultChannelPipeline.fireChannelRead(DefaultChannelPipeline.java:965)
	at io.netty.channel.nio.AbstractNioByteChannel$NioByteUnsafe.read(AbstractNioByteChannel.java:163)
	at io.netty.channel.nio.NioEventLoop.processSelectedKey(NioEventLoop.java:647)
	at io.netty.channel.nio.NioEventLoop.processSelectedKeysOptimized(NioEventLoop.java:582)
	at io.netty.channel.nio.NioEventLoop.processSelectedKeys(NioEventLoop.java:499)
	at io.netty.channel.nio.NioEventLoop.run(NioEventLoop.java:461)
	at io.netty.util.concurrent.SingleThreadEventExecutor$5.run(SingleThreadEventExecutor.java:884)
	at io.netty.util.concurrent.FastThreadLocalRunnable.run(FastThreadLocalRunnable.java:30)
	at java.lang.Thread.run(Thread.java:748)
</code></pre></div>