<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/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: master</li>
<li>Operating System version: windows</li>
<li>Java version: 1.8</li>
</ul>
<h3 dir="auto">Steps to reproduce this issue</h3>
<ol dir="auto">
<li>update that how to judge the same weight</li>
<li>update that weights and how to judge the index depend on offset</li>
</ol>
<p dir="auto">Pls. provide [GitHub address] to reproduce this issue.</p>
<h3 dir="auto">Expected Result</h3>
<ol dir="auto">
<li>enhance performance</li>
<li>code is clear</li>
</ol>
<p dir="auto">What do you expected from the above steps？</p>
<h3 dir="auto">Actual Result</h3>
<p dir="auto">What actually happens?</p>
<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: 2.7.1</li>
<li>Operating System version: Windows 10</li>
<li>Java version: 1.8</li>
</ul>
<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="java.lang.IllegalStateException: No such extension org.apache.dubbo.registry.RegistryFactory by name nacos
	at org.apache.dubbo.common.extension.ExtensionLoader.findException(ExtensionLoader.java:516)
	at org.apache.dubbo.common.extension.ExtensionLoader.createExtension(ExtensionLoader.java:523)
	at org.apache.dubbo.common.extension.ExtensionLoader.getExtension(ExtensionLoader.java:347)
	at org.apache.dubbo.registry.RegistryFactory$Adaptive.getRegistry(RegistryFactory$Adaptive.java)
	at org.apache.dubbo.registry.integration.RegistryProtocol.getRegistry(RegistryProtocol.java:273)
	at org.apache.dubbo.registry.integration.RegistryProtocol.export(RegistryProtocol.java:187)
	at org.apache.dubbo.qos.protocol.QosProtocolWrapper.export(QosProtocolWrapper.java:61)
	at org.apache.dubbo.rpc.protocol.ProtocolListenerWrapper.export(ProtocolListenerWrapper.java:55)
	at org.apache.dubbo.rpc.protocol.ProtocolFilterWrapper.export(ProtocolFilterWrapper.java:106)
	at org.apache.dubbo.rpc.Protocol$Adaptive.export(Protocol$Adaptive.java)
	at org.apache.dubbo.config.ServiceConfig.doExportUrlsFor1Protocol(ServiceConfig.java:559)
	at org.apache.dubbo.config.ServiceConfig.doExportUrls(ServiceConfig.java:417)
	at org.apache.dubbo.config.ServiceConfig.doExport(ServiceConfig.java:375)
	at org.apache.dubbo.config.ServiceConfig.export(ServiceConfig.java:337)
	at org.apache.dubbo.config.spring.ServiceBean.export(ServiceBean.java:319)
	at org.apache.dubbo.config.spring.ServiceBean.onApplicationEvent(ServiceBean.java:113)
	at org.apache.dubbo.config.spring.ServiceBean.onApplicationEvent(ServiceBean.java:59)
	at org.springframework.context.event.SimpleApplicationEventMulticaster.doInvokeListener(SimpleApplicationEventMulticaster.java:172)
	at org.springframework.context.event.SimpleApplicationEventMulticaster.invokeListener(SimpleApplicationEventMulticaster.java:165)
	at org.springframework.context.event.SimpleApplicationEventMulticaster.multicastEvent(SimpleApplicationEventMulticaster.java:139)
	at org.springframework.context.support.AbstractApplicationContext.publishEvent(AbstractApplicationContext.java:402)
	at org.springframework.context.support.AbstractApplicationContext.publishEvent(AbstractApplicationContext.java:359)
	at org.springframework.context.support.AbstractApplicationContext.finishRefresh(AbstractApplicationContext.java:896)
	at org.springframework.context.support.AbstractApplicationContext.refresh(AbstractApplicationContext.java:552)
	at org.springframework.boot.SpringApplication.refresh(SpringApplication.java:775)
	at org.springframework.boot.SpringApplication.refreshContext(SpringApplication.java:397)
	at org.springframework.boot.SpringApplication.run(SpringApplication.java:316)"><pre class="notranslate"><code class="notranslate">java.lang.IllegalStateException: No such extension org.apache.dubbo.registry.RegistryFactory by name nacos
	at org.apache.dubbo.common.extension.ExtensionLoader.findException(ExtensionLoader.java:516)
	at org.apache.dubbo.common.extension.ExtensionLoader.createExtension(ExtensionLoader.java:523)
	at org.apache.dubbo.common.extension.ExtensionLoader.getExtension(ExtensionLoader.java:347)
	at org.apache.dubbo.registry.RegistryFactory$Adaptive.getRegistry(RegistryFactory$Adaptive.java)
	at org.apache.dubbo.registry.integration.RegistryProtocol.getRegistry(RegistryProtocol.java:273)
	at org.apache.dubbo.registry.integration.RegistryProtocol.export(RegistryProtocol.java:187)
	at org.apache.dubbo.qos.protocol.QosProtocolWrapper.export(QosProtocolWrapper.java:61)
	at org.apache.dubbo.rpc.protocol.ProtocolListenerWrapper.export(ProtocolListenerWrapper.java:55)
	at org.apache.dubbo.rpc.protocol.ProtocolFilterWrapper.export(ProtocolFilterWrapper.java:106)
	at org.apache.dubbo.rpc.Protocol$Adaptive.export(Protocol$Adaptive.java)
	at org.apache.dubbo.config.ServiceConfig.doExportUrlsFor1Protocol(ServiceConfig.java:559)
	at org.apache.dubbo.config.ServiceConfig.doExportUrls(ServiceConfig.java:417)
	at org.apache.dubbo.config.ServiceConfig.doExport(ServiceConfig.java:375)
	at org.apache.dubbo.config.ServiceConfig.export(ServiceConfig.java:337)
	at org.apache.dubbo.config.spring.ServiceBean.export(ServiceBean.java:319)
	at org.apache.dubbo.config.spring.ServiceBean.onApplicationEvent(ServiceBean.java:113)
	at org.apache.dubbo.config.spring.ServiceBean.onApplicationEvent(ServiceBean.java:59)
	at org.springframework.context.event.SimpleApplicationEventMulticaster.doInvokeListener(SimpleApplicationEventMulticaster.java:172)
	at org.springframework.context.event.SimpleApplicationEventMulticaster.invokeListener(SimpleApplicationEventMulticaster.java:165)
	at org.springframework.context.event.SimpleApplicationEventMulticaster.multicastEvent(SimpleApplicationEventMulticaster.java:139)
	at org.springframework.context.support.AbstractApplicationContext.publishEvent(AbstractApplicationContext.java:402)
	at org.springframework.context.support.AbstractApplicationContext.publishEvent(AbstractApplicationContext.java:359)
	at org.springframework.context.support.AbstractApplicationContext.finishRefresh(AbstractApplicationContext.java:896)
	at org.springframework.context.support.AbstractApplicationContext.refresh(AbstractApplicationContext.java:552)
	at org.springframework.boot.SpringApplication.refresh(SpringApplication.java:775)
	at org.springframework.boot.SpringApplication.refreshContext(SpringApplication.java:397)
	at org.springframework.boot.SpringApplication.run(SpringApplication.java:316)
</code></pre></div>