CDN caching rules in Azure - Cheat Sheet & Quick Revision

Recall & Review

beginner

What is the primary purpose of CDN caching rules?

CDN caching rules control how content is stored and served from edge servers to improve load times and reduce origin server load.

intermediate

Explain the difference between 'Cache-Control' headers and CDN caching rules.

'Cache-Control' headers are set by the origin server to guide caching behavior, while CDN caching rules are configurations on the CDN that can override or complement these headers for better control.

beginner

What does 'TTL' mean in CDN caching rules?

TTL (Time To Live) is the duration a cached object stays in the CDN edge cache before it is considered stale and fetched again from the origin.

intermediate

How can CDN caching rules improve scalability of a web application?

By caching content closer to users, CDN caching rules reduce the number of requests to the origin server, lowering server load and improving response times during traffic spikes.

beginner

Name two common conditions used in Azure CDN caching rules.

Common conditions include matching URL path patterns and HTTP request headers to apply specific caching behaviors.

What does setting a longer TTL in CDN caching rules do?

A Forces the CDN to always fetch from origin

B Keeps content cached longer at the edge servers

C Disables caching completely

D Deletes cached content immediately

A longer TTL means cached content stays longer at edge servers before refreshing.

Which header can Azure CDN caching rules override?

A Cache-Control

B Content-Type

C Authorization

D User-Agent

Azure CDN caching rules can override Cache-Control headers to customize caching.

What is a benefit of using path-based caching rules in Azure CDN?

A Different cache durations for different URL paths

B Disabling HTTPS

C Changing server IP addresses

D Blocking user access

Path-based rules allow setting different caching policies per URL path.

If content changes frequently, what caching strategy is best?

A Long TTL

B Cache forever

C Short TTL or no caching

D Disable origin server

Short TTL ensures fresh content by frequently updating cache.

Which Azure CDN feature helps to purge cached content immediately?

A Geo-filtering

B Load balancing

C SSL termination

D Content purge

Content purge removes cached content from CDN edge servers instantly.

Describe how CDN caching rules work in Azure and why they are important for web performance.

Think about how caching saves time and resources.

Explain how you would configure caching rules for a website with both static images and frequently updated news articles.

Consider content type and update frequency.