RocketMQ Netty NioSocketChannel stuck on read fd 0
- Dominant language
- Java
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Description
### 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
Both CentOS and OpenEuler met
### RocketMQ version
RocketMQ 4.9.x
### JDK Version
OpenJDK 17.0.2, we use ZGC.
### Describe the Bug
We met a extremely strange problem in rocketmq, a netty workerGroup thread hung on sun.nio.ch.SocketDispatcher.read0(workerGroup thread we set 3), then this server's 1/3 another tcp events can't be processed. See details in https://github.com/netty/netty/issues/15746, I wonder if anyone met this.
Then we rollback our production cluster to rocketmq 4.8 & jdk 8, problem is not reproduced.
Environment: rocketmq 4.9.4 on jdk 17.0.2
### Steps to Reproduce
we dont't know how to reproduce
### What Did You Expect to See?
-
### What Did You See Instead?
-
### Additional Context
_No response_
Contributor guide
Research direction
Start with the reported RocketMQ 4.9.4, OpenJDK 17.0.2, ZGC environment and compare it with RocketMQ 4.8 on JDK 8. Read the linked Netty issue and investigate the workerGroup hang at sun.nio.ch.SocketDispatcher.read0; the issue currently provides no reproduction steps, so done means isolating a reproducible cause and validating a fix.
Written by the indexing model from the issue text.
Assessment
- Tech stack
- java
- Domain
- backend, networking
- Issue type
- Bug
- Difficulty
- 4/5
- Estimated time
- 3-5 days
- Activity status
- Active
- Clarity
- Needs clarification
- Newbie friendliness
- 35/100