[ROCKETMQ-211] There should be a namespace mechanism in Message properties to avoid conflict

• Type: Bug
• Status: Open
• Priority: Minor
• Resolution: Unresolved
• Affects Version/s: 4.0.0-incubating, 4.1.0-incubating, 4.2.0, 4.3.0
• Component/s: rocketmq-commons
• Environment: All Environments
• Assignee: Jixiang Jin
• Reporter: binzhaomobile
• Created: 04/Jun/17 02:43
• Updated: 20/Jun/17 05:19

Description

There are tow kinds of Message properties: RocketMQ reserved properties and user-defined properties, but they are not separated in strict way. For example ,in the following case conflict will happen:
1) The user used a user-defined Message property "PROPERTY_A" in their application based on RocketMQ4.3.
2) When developing RocketMQ4.4, a new RocketMQ reserved property also named "PROPERTY_A" is added.
3) When the user upgrade RocketMQ from 4.3 to 4.4, the application will not work well, it will receive an exception "The Property PROPERTY_A is used by system, input another please".

So, there should be a Name Space mechanism to distinguish user-defined and RocketMQ reserved properties. One approach could be: Adding a prefix, such as "USER/" or "SYSTEM/" to the property name when storing a property.