Issue Description

Type: bug report or feature request

Describe what happened (or what feature you want)

I saw a few of**@SuppressWarnings("PMD.ThreadPoolCreationRule")in many classes.
(e.gSimpleHttpCommandCenter.java , NettyHttpCommandCenter.java**)
Why did you just ignore them instead of fixing?
What if tremendous task queued in blocking queue?
It may cause OutOfMemory problem according to Alibaba Java Coding Guidelines.

Describe what you expected to happen

If possible, I will submit a PR for fixing it.
Looking forward to your reply. Thanks!

How to reproduce it (as minimally and precisely as possible)

NONE

Tell us your environment

NONE

Anything else we need to know?

NONE