微服务之间基于消息的通信

Question

I would like to build few number of microservices that send and receive message using a message broker: ActiveMQ . Now I am exploring options for message type (ie String , byte[] , object type):

1. publish msg in XML/JSON format and once received they are parsed
2. publish msg in XML/JSON format, using schema to convert them to objects
3. Create a Domain object and add to microservices dependency for data exchange

These are the 3 options I have looked at, and I am leaning towards option 1 for below mentioned reasons :

1. when a new field needs to be added only those microservices that require this field need change.
2. Different version of microservices can be deployed without breaking existing communication
3. microservices remain decoupled

However this raises the issue of parsing and extracting data which is very error prone.

I would like to know if anyone else has done a similar design and could share their experience and suggest solutions. Also if there is a better way to implement communication between microservices using messaging and queues.

Answer 1

This is the approach I usually take: for each message type, a class is responsible for both encoding the message (generating JSON/XML/whatnot), validating it and parsing it. Classes go into a library that is then used on both the service which is sending the message and on the service that is receiving it.