leizhiyuan opened a new issue, #7579: URL: https://github.com/apache/rocketmq/issues/7579
### Before Creating the Bug Report - [X] I found a bug, not just asking a question, which should be created in [GitHub Discussions](https://github.com/apache/rocketmq/discussions). - [X] I have searched the [GitHub Issues](https://github.com/apache/rocketmq/issues) and [GitHub Discussions](https://github.com/apache/rocketmq/discussions) of this repository and believe that this is not a duplicate. - [X] I have confirmed that this bug belongs to the current repository, not other repositories of RocketMQ. ### Runtime platform environment none ### RocketMQ version 4.9.x and 5.x ### JDK Version every ### Describe the Bug ``` java.util.ConcurrentModificationException: null at java.util.ArrayList$Itr.checkForComodification(ArrayList.java:911) at java.util.ArrayList$Itr.next(ArrayList.java:861) at org.apache.rocketmq.acl.plain.PlainPermissionManager.validate(PlainPermissionManager.java:712) at org.apache.rocketmq.acl.plain.PlainAccessValidator.validate(PlainAccessValidator.java:129) at org.apache.rocketmq.broker.BrokerController$10.doBeforeRequest(BrokerController.java:636) at org.apache.rocketmq.remoting.netty.NettyRemotingAbstract.doBeforeRpcHooks(NettyRemotingAbstract.java:171) at org.apache.rocketmq.remoting.netty.NettyRemotingAbstract$1.run(NettyRemotingAbstract.java:201) at org.apache.rocketmq.remoting.netty.RequestTask.run(RequestTask.java:80) at java.util.concurrent.Executors$RunnableAdapter.call(Executors.java:511) at java.util.concurrent.FutureTask.run(FutureTask.java:266) at java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1149) at java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:624) at java.lang.Thread.run(Thread.java:750) ``` because acl monitor the change of acl file ``` this.globalWhiteRemoteAddressStrategy.addAll(globalWhiteRemoteAddressStrategy); if (this.globalWhiteRemoteAddressStrategyMap.get(aclFilePath) != null) { List<RemoteAddressStrategy> remoteAddressStrategyList = this.globalWhiteRemoteAddressStrategyMap.get(aclFilePath); for (int i = 0; i < remoteAddressStrategyList.size(); i++) { this.globalWhiteRemoteAddressStrategy.remove(remoteAddressStrategyList.get(i)); } this.globalWhiteRemoteAddressStrategyMap.put(aclFilePath, globalWhiteRemoteAddressStrategy); } ``` it will change globalWhiteRemoteAddressStrategy ,but ``` public void validate(PlainAccessResource plainAccessResource) { // Check the global white remote addr for (RemoteAddressStrategy remoteAddressStrategy : globalWhiteRemoteAddressStrategy) { if (remoteAddressStrategy.match(plainAccessResource)) { return; } } ``` so one thread read ,another write ### Steps to Reproduce review ### What Did You Expect to See? normal ### What Did You See Instead? ConcurrentModificationException ### Additional Context review -- This is an automated message from the Apache Git Service. To respond to the message, please log on to GitHub and use the URL above to go to the specific comment. To unsubscribe, e-mail: commits-unsubscr...@rocketmq.apache.org.apache.org For queries about this service, please contact Infrastructure at: us...@infra.apache.org