SOA vs Microservices Architecture

SOA	MSA
Built on the idea of “share-as-much-as-possible” architecture approach	Built on the idea of “share-as-little-as-possible” architecture approach
More importance on business functionality reuse	More importance on the concept of “bounded context”
Common governance and standards	Relaxed governance, with more focus on people collaboration and freedom of choice
Uses enterprise service bus (ESB) for communication	Uses less elaborate and simple messaging system
Supports multiple message protocols	Uses lightweight protocols such as HTTP/REST & AMQP
Common platform for all services deployed to it	Application Servers not really used. Platforms such as Node.JS could be used
Multi-threaded with more overheads to handle I/O	Single-threaded usually with use of Event Loop features for non-locking I/O handling
Use of containers (Dockers, Linux Containers) less popular	Containers work very well in MSA
Maximizes application service reusability	More focused on decoupling
Uses traditional relational databases more often	Uses modern, non-relational databases
A systematic change requires modifying the monolith	A systematic change is to create a new service
DevOps / Continuous Delivery is becoming popular, but not yet mainstream	Strong focus on DevOps / Continuous Delivery