[DISCUSS] Release Apache RocketMQ 4.0.0-incubating

[yukon <yu...@apache.org>]

Hi all,

It's time to release the first RocketMQ version 4.0.0-incubating in ASF,
and some early work has been finished, like:

1. All text files contain correct licence header(Use rat:check).
2. Repackage com.alibaba to org.apache and change maven coordinate.
3. All of the code follow the unified code style (
http://rocketmq.incubator.apache.org/docs/code-guidelines/).
4. KEYS file contains signing key (https://dist.apache.org/
repos/dist/dev/incubator/rocketmq/KEYS).
5. All 4.0.0-incubating related issues has been resolved.
....

The unstable release notes is here:

https://issues.apache.org/jira/secure/ReleaseNote.jspa?projectId=12320724&version=12338919

Also there are some other new features developed before RocketMQ enter to
ASF:

1. Low latency, more than 99.6% response latency within 1 millisecond under
high stress.
2. Support broker fast failure.
3. Resolve full GC issue under tens of thousands of client connection.
4. Resolve memory leak issue in long polling request.
5. Optimize GC pause, the worst GC time around 100 ms.
....

If you think there is any issue should be resolved in 4.0.0-incubating or
you have any advice, please feel free to propose it in this email thread.

If everything is ok, we will create a VOTE email thread on dev@ later.

Regards,
yukon