YanYunyang opened a new issue, #8366: URL: https://github.com/apache/rocketmq/issues/8366
### 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 4.19.90-23-42.v2101.ky10.x86_64 ### RocketMQ version 5.2.0 ### JDK Version openjdk 1.8 ### Describe the Bug During the client shutdown process, deadlocks were detected, which resolved after a period of time. This phenomenon was observed using jvisualvm and jconsole. The deadlock occurred between the client shutdown thread and the Netty worker threads. Code analysis: 1. `NettyRemotingClient` holds the `lockChannelTables` lock, which is responsible for guarding access to `channelTables`. `channelTables` caches all channels encapsulated in `ChannelWrapper`. 2. The inner class ChannelWrapper within NettyRemotingClient` holds a read-write lock `lock`, responsible for concurrent access to the channel. 3. The inner class `NettyConnectManageHandler` in `NettyRemotingClient` is responsible for handling events like close, connect, and channelInactive. When a channel becomes unavailable, it executes the `close` or `channelInactive` methods to remove the channel from `channelTables`. <img width="1057" alt="截屏2024-07-05 14 11 28" src="https://github.com/apache/rocketmq/assets/11780013/e42afcc4-9faa-4a2b-a495-44b2cd6eb550";> <img width="1180" alt="截屏2024-07-05 14 15 06" src="https://github.com/apache/rocketmq/assets/11780013/aabc96c2-843a-4133-bbc8-81ac2d026d65";> <img width="1197" alt="截屏2024-07-05 14 19 16" src="https://github.com/apache/rocketmq/assets/11780013/7e47c007-ac4d-43d5-acad-3d8890ae6e89";> <img width="1431" alt="截屏2024-07-05 14 26 54" src="https://github.com/apache/rocketmq/assets/11780013/9c381594-956f-4859-90eb-9cb81ff592c4";> The execution path where deadlock occurs. <img width="857" alt="截屏2024-07-05 15 22 22" src="https://github.com/apache/rocketmq/assets/11780013/184180d8-cdf3-4f2c-9b10-e028fa4f410e";> ### Steps to Reproduce  1.Creating multiple consumer clients and shutting them down one by one. The more clients are created, the more likely a deadlock will be triggered. 2.Open jconsole and continuously click on deadlock detection.[](url) ### What Did You Expect to See?  deadlocks were detected. ### What Did You See Instead? deadlocks were detected. ### Additional Context _No response_ -- 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
