Monolith VS Microservice

Monolith

• Single App, everything inside, UI, backend, database, etc.

• Advantages:

  • Simplified architecture.

  • Less time worrying the complexity of distributed systems.

  • Less time worrying about deployment of the system.

• Disadvantages:

  • Scalability, hard to scale.

  • Sometimes hard to debug. For example memory leak happened in Netflix early days.

  • If one part of the program is down, then everything is down.

Microservice

• Approach to develop single application as a suite of small services. Each running its own process and communicating with lightweight mechanism.

• Advantages:

  • Separation of concerns.

  • Modularity and encapsulation.

  • Scalability, easy to do horizontal scaling and workload partition.

  • Virtualization: It is recommended to use virtual environment for less complex deployment (on demand resource & auto scaling).

• Disadvantage:

  • Much more complex to build.

  • Prone to network partition, see [[cap_theorem]] for more detail.