Request new feature for the message track

[zongtanghu]

What is the purpose of the change
1.Message track trace refers to the consumption processing of a message which is sent from the producer instance has arrived the broker,and then has been consumed by the consumer instance.In the whole process, the information of time, location and other related services(including Client and Broker) is aggregated into the complete link information of message communication.
In MQ system, the complete link of a message contains three roles: producer, broker server and consumer.In the process of message communicaton, each role adds relevant information to the track trace link.By aggregating these information,it can provide some powerful support to user.

Brief changelog
1.I will define a special broker node which is used to store the messages track trace data.
2.In RocketMQ client,I will add some codes to send the messages trace data to special broker node asynchronously.

Verifying this change
3.We can run the nameserver,broker and console components.By the console admin page,we can view the message track trace data.

[vongosling]

cool, @zongtanghu Messaging tracing is a very important feature. Could you make your proposal as the RIP(http://rocketmq.apache.org/community/)? It would be helpful for community guys involvement.

[zongtanghu]

@vongosling OK，these days，I will make my proposal as the RIP,including my detailed design.

[zongtanghu]

Hi @vongosling @duhengforever @dongeforever ,I have already made my RIP and send it to those mail list(such as dev,user and commits).

[vongosling]

@zongtanghu Got it. It seems to be good for PMC. Could you call for a vote after the 72 hours?

the process for the rip, please refer to http://rocketmq.apache.org/community/

[zongtanghu]

OK，I know about the process for RIP.Thank you very much. @vongosling @dongeforever @duhengforever

[zongtanghu]

Hi @vongosling @duhengforever @dongeforever I have already commit and push the important codes in the part of rocketmq.The pull request url is:#537 review them.And I will fix some small issues in part of console and push it.