Edge Cache

Edge caching is handled via Nginx's built in HTTP caching.

Benefits of Caching

Caching helps you speed up your website by saving responses and serving it directly from disk and memory. It also helps you handle high traffic loads and in some cases fight DDoS attacks. Nginx will almost always be able to serve more requests than your application because it does not have to perform any logic to generate responses.

What to cache?

The most commonly cached items are static content such as images, videos, css, etc. These are perfect for caching because its contents are not dynamically generated. You can still cache dynamic content, but you must set an appropriate Edge Cache TTL and purge when necessary.

Default Nginx Cache Settings

These are the default cache settings for Nginx used by LightPath. You can change these in your nginx.conf file on line 115

Value: proxy_cache_path /var/cache/nginx levels=1:2 keys_zone=global_cache:100m max_size=5g inactive=1d use_temp_path=off

• Store cache at /var/cache/nginx
• Use 2 level directory hierarchy
• Max item size is 5 GB
• Delete items that haven't been accessed in 1 day (The max Edge Cache TTL for LightPath)

Options

You can change these options on the dashboard under "Cache" or through the API at PUT - /v1/zones/:id/cache

Purge Cache

Clear items from edge cache forcing requests to be forwarded to the origin

• Custom Purge - Purge specific items using URLs
• Purge All - Purge all items in zone from edge cache

Cache TTL

The amount of time a cache item should be stored on an edge server

• Store cache for x amount of time - 30 minutes, 1 hour, 2 hours, 3 hours, 4 hours, 5 hours, 8 hours, 12 hours, 16 hours, 20 hours, 1 day
• Bypass Cache - Bypass edge cache and pull from origin
• Respect Origin - Use cache-control headers from origin

Sorted Query String

Sort query strings alphabetically, allowing files with different query string orders to be treated the same

Strip Cookies

Removes the set-cookie header from origin server