when DefaultMQProducerImpl shutdown didn't shutdown some demon thread.

[lilylei013]

BUG REPORT

1. Please describe the issue you observed:

• What did you do (The steps to reproduce)?
  start a DefaultMQProducer producer , after send message , then shutdown it, but the main thread is not finish.

• What did you expect to see?
  I want all the MQ producer relative threads is finished.

• What did you see instead?
  there is still some demon threads left there .
  RequestHouseKeepingService , and AsyncAppender-Dispatcher-Thread-3,4,6

2. Please tell us about your environment:
   windows 64bit eclipse
3. Other information (e.g. detailed explanation, logs, related issues, suggestions how to fix, etc):
   for the RequestHouseKeepingService , there is because timer is not shutdown
   for the AsyncAppender-Dispatcher-Thread , I didn't found it now

[RongtongJin]

Hi @lilylei013 What version are you using? I used the latest version and there seems to be no such issue.

[lilylei013]

I checked 4.7.0 version, it's not fix. It's the timertask which is not cancel

[coder-zzzz]

I found this issue #1957 today, but didn't find this issue #1950.I already commit a pr #1958 to fix #1957

[coder-zzzz]

I think the AsyncAppender-Dispatcher-Thread is used by log, so it is usefull , can not shutdown when producer shutdown

[lilylei013]

Just cancle the timer when producer shutdown it's okay