Alibaba Cloud Certified Associate (ACA) Practice Test 2025 – Complete All-in-One Guide for Exam Success!

The client application is responsible for initiating the call process in a microservice architecture. This is because microservices are designed around independent services that communicate over a network. Typically, the client application is the entry point for users interacting with the system.

When a user interacts with the client application, it makes requests to various microservices to fulfill actions or retrieve data. This can involve sending HTTP requests to APIs exposed by the microservices. By initiating the call process, the client application manages the user experience and orchestrates communication among the different services to provide the necessary functionality.

The other components listed serve different roles within the architecture. The resource request generally refers to the action taken by the client application to seek specific data or services but does not initiate the call by itself. The authentication service plays a role in verifying the identity of users before they can interact with the microservices, ensuring secure access but not initiating the calls. The load balancer distributes incoming requests among multiple instances of microservices to ensure efficient processing and high availability, but it does not originate the call; it responds to the requests coming from the client application.