Learning Scala Web Development (Video 20)

The video tutorial introduces the concept of caching in web services and APIs, emphasizing its importance in improving performance. It covers various caching techniques supported by the HTTP protocol, such as cache control headers and entity tags (E-tags). The tutorial explains how caching can speed up request processing by serving data from the cache instead of fetching it anew. It also highlights the challenges of cache invalidation. The video concludes with a brief overview of the spray caching module, which will be explored in the next section.

What is one of the main benefits of effective caching in web services?

• Improved data accuracy

• Increased data storage

• Faster request processing

• Reduced server costs

Which of the following is a challenge associated with caching?

• Data redundancy

• Cache invalidation

• Network latency

• Data encryption

What is the purpose of the cache control header in HTTP 1.1?

• To authenticate users

• To compress data

• To define caching policies

• To encrypt data

Which header is used for time-based caching in HTTP?

• Content-Type

• User-Agent

• Authorization

• Expires

What is an ETag in the context of HTTP caching?

• A type of cookie

• A unique identifier for a resource version

• A network protocol

• A data encryption method

How does a server use ETags to determine if a resource has changed?

• By verifying the user identity

• By analyzing the request time

• By comparing ETag values

• By checking the resource size

What HTTP status code is returned when a resource has not been modified?

• 500 Internal Server Error

• 304 Not Modified

• 404 Not Found

• 200 OK