CDN caching for static content in HLD - Interactive Code Practice

Practice - 5 Tasks

1fill in blank

easy

Complete the code to specify the cache expiration header for static content.

HLD

Cache-Control: max-age=[1]

Drag options to blanks, or click blank then click option'

Agzip

Bno-cache

Ctext/html

D3600

Attempts:

3 left

💡 Hint

Common Mistakes

Using 'no-cache' disables caching, which is not desired for static content.

The max-age directive sets the cache expiration time in seconds. For static content, a value like 3600 seconds (1 hour) is common.

2fill in blank

medium

Complete the code to define the CDN edge server behavior for cache miss.

HLD

If cache miss, fetch content from [1]

Drag options to blanks, or click blank then click option'

Aclient browser

Banother CDN

Corigin server

Dlocal cache

Attempts:

3 left

💡 Hint

Common Mistakes

Thinking the client browser provides content on cache miss.

On a cache miss, the CDN edge server fetches the content from the origin server.

3fill in blank

hard

Fix the error in the cache key definition for CDN caching.

HLD

Cache key = URL + [1]

Drag options to blanks, or click blank then click option'

Arequest headers

Bresponse body

Cserver logs

Dclient IP

Attempts:

3 left

💡 Hint

Common Mistakes

Including response body or server logs in cache key is incorrect.

The cache key usually includes the URL and relevant request headers like cookies or query strings to differentiate cached content.

4fill in blank

hard

Fill both blanks to configure CDN cache invalidation correctly.

HLD

To invalidate cache, send a [1] request to the CDN with the [2] URL.

Drag options to blanks, or click blank then click option'

APURGE

BGET

Ctarget

Dsource

Attempts:

3 left

💡 Hint

Common Mistakes

Using GET instead of PURGE for invalidation.

Cache invalidation is done by sending a PURGE request to the CDN specifying the target URL to remove from cache.

5fill in blank

hard

Fill all three blanks to define a cache-control header that allows CDN caching but forces revalidation after expiry.

HLD

Cache-Control: public, max-age=[1], [2], [3]

Drag options to blanks, or click blank then click option'

Amust-revalidate

B3600

Cproxy-revalidate

Dno-store

Attempts:

3 left

💡 Hint

Common Mistakes

Using no-store disables caching entirely.

This header means the content is public, cached for 3600 seconds, proxies must revalidate after expiry, and clients must also revalidate.