Explore key concepts of building microservices with Nest.js, including project structure, communication patterns, and designing scalable delivery service applications. This quiz assesses your grasp on core microservice patterns, the split between monolithic and monorepo approaches, and the main features of a sample rider tracking app—ideal for anyone learning scalable backend development with JavaScript.
What is the primary responsibility of the logging service in the described delivery application?
Explanation: The logging service is dedicated to saving and fetching the rider's coordinates at regular intervals. Processing payments and displaying ratings are not part of its described functionalities and would typically belong in separate services. Managing login credentials is handled by the rider service, not the logging service.
In the project, what is one main feature provided by the rider service?
Explanation: The rider service is responsible for features like rider signup (registering new riders), login, and providing rider details. Calculating delivery fees, recording package weight, and generating tracking numbers are outside its scope. These features would belong to other services within the system.
Which type of database is mentioned as being used for storing rider coordinates in the microservices example?
Explanation: MongoDB was referenced as the database used for saving rider coordinates in the example. While other databases like Firebase, PostgreSQL, and Redis could be used, they were not specifically mentioned in the example. The design allows flexibility in database selection.
Why is the microservices architecture considered beneficial according to the course example?
Explanation: The key benefit highlighted is that each microservice can be independently deployed, allowing for flexibility and scalability. Microservices do not require the same language or a single shared database, and blocking communication between services is a disadvantage, not a benefit.
What are the two main code organization modes in Nest.js mentioned in the tutorial?
Explanation: Nest.js offers standard mode (often used for smaller or monolithic projects) and monorepo mode (ideal for microservices and code sharing across teams). The other options do not represent code organization modes in Nest.js.
Which code organization mode is generally recommended in Nest.js for microservices with multiple teams?
Explanation: Monorepo mode is favored for microservices projects, especially when multiple teams are working on various services and code needs to be shared easily. Standard mode is suitable for smaller or individual projects. The other options do not exist as recognized project structures.
What is the default port on which a new Nest.js project runs if not otherwise specified?
Explanation: By default, Nest.js launches the server on port 3000. The other port numbers are common defaults in different frameworks or applications but are not the default for a new Nest.js project.
Which type of communication approach is highlighted in the course for microservices interaction?
Explanation: The course specifically mentions using TCP-based communication between microservices for efficient and reliable data transfer. HTTP polling and WebSockets are alternative methods but were not emphasized here, and email messaging is unrelated to internal microservice communication.
What type of API endpoints are mentioned for the logging service to manage rider coordinates?
Explanation: The logging service uses POST endpoints for saving data and GET endpoints for retrieving single or multiple records. DELETE, PATCH, PUT, OPTIONS, TRACE, and CONNECT are valid HTTP methods but do not match the described implementation for this scenario.
Why would a development team choose monorepo mode for their Nest.js microservices project?
Explanation: Monorepo mode is advantageous because it enables easier code sharing and management between multiple microservices. It does not prevent team collaboration or restrict code reuse; in fact, it enhances these. Combining all code into one file is not a feature or benefit of monorepo mode.
Which Nest.js CLI command is used to add a new microservice app and convert a standard project to monorepo mode?
Explanation: The 'Nest generate app' command adds a new application (microservice) and transitions the workspace to monorepo mode. The other commands do not perform this exact function; 'Nest new' creates a new project, while 'Nest build' and 'Nest create service' have different purposes.
After converting to monorepo mode, where are individual microservice applications stored within the Nest.js project?
Explanation: When using monorepo mode, each microservice project appears in its own subfolder inside the 'apps' directory. The 'dist' folder is used for compiled code, 'src' is used in standard mode for source code, and storing directly under the root is incorrect in monorepo setups.
Which command is typically used to start a new Nest.js project using npm?
Explanation: 'nest new project-name' is the standard command to initialize a new Nest.js project using the CLI. The other options are either not valid CLI commands or do not perform project setup.
What is the main business goal of tracking rider coordinates in the delivery service example?
Explanation: Storing rider coordinates every few hours lets the business review and analyze a rider's daily activity patterns. Tax calculations, storing emails, and generating advertisements are important in other contexts but are not the purpose of the tracking feature as described.
In monorepo mode, what is a key feature regarding the package.json file?
Explanation: A single package.json is shared, which simplifies dependency management across all the microservice apps in the monorepo. Having multiple package.json files is not the default, and eliminating the file entirely is neither valid nor possible for JavaScript projects using npm.
Why is it important to have an up-to-date Nest.js CLI before starting a new project?
Explanation: Having the latest Nest.js CLI helps you access recent features, improvements, and proper command usage. Using outdated CLI versions can cause compatibility issues, but it won't slow down development or lock you to older code by itself, nor will it impact if you can use npm.