SCSs and Microservices
In this lesson, we'll study the relationship between SCSs and microservices.
We'll cover the following
SCSs stand out from deployment monoliths in the same way as microservices. A deployment monolith would implement the entire application in a single deployable artifact while SCSs divide the system into several independent web applications.
Because an SCS is a separate web application, it can be deployed independently of the other SCSs. SCSs are also modules of an overall system. Therefore, SCSs are independently deployable modules and consequently correspond to the definition of microservices.
One SCS can be split into several microservices#
However, an SCS may be split into several microservices. If the payment in the check out SCS of an e-commerce system causes a particularly high load, then it can be implemented as a separate microservice which can be scaled separately from the rest of the check out SCS. So, the check out SCS consists of a microservice for payment and contains the rest of the functionality in another microservice.
Another reason for separating a microservice from an SCS is the security advantage offered by greater isolation. Additionally, domain services that calculate the price of a product or quotation for all SCSs can be a useful shared microservice. The microservice should be assigned to a team like an SCS in order to avoid too much coordination.
Summary#
In summary, microservices and SCSs differ in the following ways:
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Typically, microservices are smaller than SCSs. An SCS can be so large that an entire team is busy working on it. Microservices can potentially have only a few hundred lines of code.
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SCSs focus on loose coupling. There is no such rule for microservices, although tightly coupled microservices have many disadvantages and therefore should be avoided.
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In any case, an SCS must have a UI. Many microservices offer only a technical interface for other microservices but no user interface.
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SCSs recommend UI integration or asynchronous communication; synchronous communication is allowed but not recommended. Large microservices systems such as Netflix also focus on synchronous communication.
Q U I Z
If an SCS can be separated into several microservices, it is still a good idea for the original team to work on all the microservices.
A)
True
B)
False
In the next lesson, we’ll look at some challenges pertaining to using SCSs.
