Lesson 9: Client-Server Comms, Google Chrome Network Tab & Related Interview Question
Request Headers
Additional information sent with a request.
Response Headers
Additional information sent with a response.
API
Application Programming Interface, a set of rules and protocols for building software applications.
What are APIs?
Application Programming Interfaces that allow software to communicate.
How do you ensure that the network activity is not cleared when navigating away from the page?
Check the box next to 'Preserve log' in the 'Network' tab.
What is client-server architecture?
Client makes request, server provides response.
What do 3XX-level responses indicate?
Client must take additional action to complete their request.
How does client-server architecture work?
Clients send requests to servers, which respond with data.
Response Body
Data sent back in response to a request.
Request Body
Data sent with a request, usually in JSON or XML format.
How do you navigate to the 'Network' tab in Chrome DevTools?
In the DevTools window, navigate to the 'Network' tab.
What do APIs define?
Methods and data formats for client-server communication.
What is client-server architecture?
Model where multiple clients connect to a central server.
How do you view an API login request in Chrome DevTools?
Open Google Chrome and navigate to the webpage where the API login request is made. Then, open Chrome DevTools by pressing F12 or right-clicking and selecting 'Inspect'.
What is the most popular tool for API testing?
Postman.
What does the server do with the client's requests?
Processes the requests and retrieves necessary data.
What do 4XX-level responses indicate?
Request was received, but there was an error from the client.
What do 2XX-level responses indicate?
Request was received, understood, and processed successfully.
What types of requests can the client send to the server in this architecture?
Requests for data and services.
How do the client and server communicate?
Similar to a customer and waiter with the help of a menu.
What is API testing?
Testing APIs manually or using tools.
What does the 'Network' tab in Chrome DevTools show?
The 'Network' tab shows all network activity on the page, including API requests.
What does the server send back to the client?
The requested information for display in the user's web browser.
HTTP Method
The type of action to be performed on a resource (GET, POST, etc.).
What do 5XX-level responses indicate?
There was a server error (usually backend bugs).
How do the client and server interact?
Through a well-defined interface.
What are status codes used for?
To describe the result of a REST request.
Why should client-server architecture be tested?
To ensure functionality, security, and performance.
Why is understanding client-server architecture important for a QA Engineer?
To identify potential issues and ensure correct communication.
What is the role of the client in client-server architecture?
To make requests to the server.
What is the role of the server in client-server architecture?
To process requests and provide responses.
What is the role of a client in client-server architecture?
To request services from servers.
What do 1XX-level responses communicate?
Transfer protocol-level information.
URL
Uniform Resource Locator, the address used to access a resource on the web.
How can Chrome DevTools help with API login request testing?
Verify request content, response data, and completion time.
What are common QA use cases for Chrome DevTools?
Verifying requests, inspecting request properties, copying requests for testing.
What is an example of client-server architecture?
Web browsers connecting to web servers on the Internet.
What is Chrome DevTools?
Web developer tools in Chrome browser.
Can the server handle multiple requests at the same time?
Yes, just like a waiter serving multiple tables.
What are the steps to view an API login request in Chrome DevTools?
1. Open Google Chrome and navigate to the webpage where the API login request is made. 2. Open Chrome DevTools. 3. Navigate to the 'Network' tab. 4. Check the box next to 'Preserve log'.
How many categories do status codes fall into?
5 categories.
Client Server Database (DB)
A database used in a client-server architecture.
Request
A message sent by a client to a server to request data or services.
Response
A message sent by a server to a client containing requested data or services.
Client-server architecture
A model where clients request services from servers.
What is client-server architecture?
A model where clients request services from servers.
Status code
A number indicating the success or failure of a request.
GET request
A request to retrieve data from a server.
POST request
A request to send data to a server to create a new record.
What is an API?
A set of rules that allow software applications to communicate.
Database
A storage mechanism where data is stored and retrieved.
Client-server architecture
A system where clients request services from servers.
What is client-server architecture?
A system where clients request services from servers.
