Cache bypass conditions in Nginx - Cheat Sheet & Quick Revision

Recall & Review

beginner

What is a cache bypass condition in nginx?

A cache bypass condition tells nginx when to skip using the cache and fetch fresh content directly from the server.

beginner

How can you bypass cache based on a request method in nginx?

You can bypass cache by checking if the request method is not GET or HEAD, since usually only these methods are cached.

beginner

What directive is used to define cache bypass conditions in nginx?

The directive 'proxy_cache_bypass' is used to specify conditions under which nginx will bypass the cache.

intermediate

Give an example of a cache bypass condition using a cookie in nginx.

You can bypass cache if a specific cookie exists, for example: proxy_cache_bypass $cookie_nocache;

intermediate

Why is it important to set cache bypass conditions carefully?

Because improper bypass conditions can cause stale content to be served or reduce cache efficiency, slowing down your site.

Which nginx directive controls when to skip the cache?

A proxy_cache_valid

B proxy_cache_path

C proxy_cache_bypass

D proxy_cache_key

The 'proxy_cache_bypass' directive tells nginx when to bypass the cache.

Which HTTP request methods are typically cached in nginx?

A GET and HEAD

B POST and PUT

C DELETE and PATCH

D OPTIONS and TRACE

Only GET and HEAD requests are usually cached because they are safe and idempotent.

How can you bypass cache when a user is logged in using nginx?

A Disable proxy_cache_path

B Use proxy_cache_valid 0

C Set proxy_cache_key to user ID

D Check for a session cookie and use proxy_cache_bypass

By checking a session cookie with proxy_cache_bypass, nginx can skip cache for logged-in users.

What happens if you do not set any cache bypass conditions?

A All requests may be served from cache, even when fresh content is needed

B Cache is always bypassed

C Cache is disabled

D Nginx will throw an error

Without bypass conditions, nginx may serve stale content from cache when fresh content is required.

Which variable can be used to bypass cache based on a query string?

A $host

B $arg_nocache

C $http_cookie

D $request_method

The variable '$arg_nocache' checks for a query string parameter to bypass cache.

Explain how to configure nginx to bypass cache for POST requests and logged-in users.

Think about conditions that tell nginx when to skip cache.

Describe why cache bypass conditions are important for website performance and content freshness.

Consider the balance between speed and freshness.