Caching CDN Contents and How Would it Help My Business

Caching CDN

Caching is the process of storing copies of files in a cache, or temporary storage location, so that they can be accessed more quickly. Technically, a cache is any temporary storage location for copies of files or data, but usually the term is used in reference to Internet technologies. DNS servers cache DNS records for faster lookups, CDN servers cache content to reduce latency, and web browsers cache HTML files, JavaScript, and images in order to load websites more quickly.

To understand how caches work, consider real-world caches of food and other supplies. When explorer Roald Amundsen made his return journey from his trip to the South Pole in 1912, he and his men subsisted on the caches of food they had stored along the way. This was much more efficient than waiting for supplies to be delivered from their base camp as they traveled. Caches on the Internet serve a similar purpose; they temporarily store the ‘supplies’, or content, needed for users to make their journey across the web.

What is CDN Caching?

A CDN, or content delivery network, caches content (such as images, videos, or webpages) in proxy servers that are located closer to end users than origin servers. (A proxy server is a server that receives requests from clients and passes them along to other servers.) Because the servers are closer to the user making the request, a CDN is able to deliver content more quickly.

Think of a CDN as being like a chain of grocery stores: Instead of going all the way to the farms where food is grown, which could be hundreds of miles away, shoppers go to their local grocery store, which still requires some travel but is much closer. Because grocery stores stock food from faraway farms, grocery shopping takes minutes instead of days. Similarly, CDN caches ‘’ the content that appears on the Internet so that webpages load much more quickly.

Caching is at the heart of content delivery network (CDN) services. Similar to how browser caching stores files on a hard drive, where they can be more rapidly accessed, a CDN moves your website content to powerful proxy servers optimized for accelerated content distribution.

What can caching do for your business?

  1. Cut down on bandwidth costs

    Delivering content from CDN cache proxies removes the burden from the origin (backend) server, significantly reducing bandwidth costs associated with serving content to numerous visitors. For most sites, bandwidth costs can be reduced by as much as 40% to 80%, depending on the percentage of cacheable content.

  2. Improve user experience

    A globally distributed network of cache proxy servers, CDNs bring your website’s content closer to all visitors, no matter where they are. Having this content delivered from a local server significantly improves access speed and user experience.

  3. Ensure reliable content delivery

    Modern CDNs have traffic capacity far exceeding most normal enterprise network capabilities. Where a self-hosted website may be easily disrupted by unexpected traffic peaks or denial of service attacks, CDN cache servers are highly resilient and secure. As a result, they are stable during peak traffic instances

How do Cache CDN Servers Work?

Proxy cache servers are the building blocks of a CDN’s network data centers, which are strategically situated around the globe. These points of presence (PoP) are selected based on traffic patterns of individual regions.

Highly active locations with numerous users may have several data centers. On the other hand, remote locations with few users may have only one PoP to cover a large geographic region.

Once in place, cache servers act as a repository for website content, providing local users with accelerated access to cached files. The closer a cache server is to the end user, the shorter the connection time needed for transmission of website data.

Hardware wise, a typical individual cache server is a content delivery powerhouse, with bolstered RAM and SSD storage resources. Being the faster option, RAM is used for high-priority resources, while SSD is used for your least requested, but still cacheable web files.

Cache options you must have

  1. Purge cache

    It gives you the ability to refresh cached files on call. Note that some providers will only allow you to refresh the entire cache storage. Also, in some cases your CDN provider will limit the number of purges over a given time period. The effectiveness of a purging request is measured in the time it takes for it to propagate through the entire network.

  2. Always/Never cache

    Helps you manually override cache headers, tagging files that should be always served or never served from cache. This is an effective tool for cache management, especially when combined with bulk management options that allow you to apply these directives to entire groups of files (e.g., all JPG files in /template/images/ folder).

  3. Cache for period

    A refinement of the Always cache option, this allows you to set a specific period during which the object should be served from cache before refreshing. Accessed from the CDN GUI, this allows easier management of specific files. However, this option is most useful when used for bulk file management (e.g., all JS files that are cached for five days).

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