One dimension scalability

Monolithic applications that are large when scaled, scale everything as all the components are bundled together. For example, in the case of a restaurant table reservation application, even if you would like to scale the table-booking service, it would scale the whole application; it cannot scale the table-booking service separately. It does not utilize the resources optimally.

In addition, this scaling is one-dimensional. Running more copies of the application provides the scale with increasing transaction volume. An operation team could adjust the number of application copies that were using a load-balancer based on the load in a server farm or a cloud. Each of these copies would access the same data source, therefore increasing the memory consumption, and the resulting I/O operations make caching less effective.

Microservices gives the flexibility to scale only those services where scale is required and it allows optimal utilization of the resources. As we mentioned previously, when it is needed, you can scale just the table-booking service without affecting any of the other components. It also allows two-dimensional scaling; here we can not only increase the transaction volume, but also the data volume using caching (Platform scale).

A development team can then focus on the delivery and shipping of new features, instead of worrying about the scaling issues (Product scale).

Microservices could help you scale platform, people, and product dimensions as we have seen previously. People scaling here refers to an increase or decrease in team size depending on microservices' specific development and focus needs.

Microservice development using RESTful web-service development makes it scalable in the sense that the server-end of REST is stateless; this means that there is not much communication between servers, which makes it horizontally scalable.