What is microservice ?

Microservice means splitting a large complex system into small sub system that can communicate each other. It is vertically scallable on its business requirements. Let's take an example. In an e commerce site there are option for view the items , add to cart option and order the item. Here every part is a microservice that are communicating each other. 

Characteristic of microservices : 

1) lighteweight application. The whole application split into seperate processes and each process have multiple modules.

2) vertically scallable.

3) microservice application can be deployed independently.

4) microservices communicates each other through network call.

Advantages of microservices :

1) Multiple teams can work together.

2) Development scaling is higher.

3) If some microservice shut down or not working , other microservices will be still working and never make the site completely down.

4) Easy for devops operation.

5) Upgradation is easy.

Disadvantages of microservices:

1)Complexity moves from code to infrastructure.

2) So many microservices makes the system architecture very hard.

3) Managing the security will be challenging.

Every microservices have its own database. It makes loose coupling among the services. But microservices make sharing of data challenging as the proper design is very important.