Cache

Cache refers to a small amount of memory that is quick and inexpensive to read and write from. Its primary purpose is to store recently used data so that future requests for the same data can be served more quickly. By using caching, the load on the website and server is reduced, as certain data is served directly from memory, instead of requiring slower queries to a database or remote server every time that data is needed.

Caching strategies can be implemented at various layers of a website, but the most common type is server-side caching.

What is cache used for?

In web development, server-side cache is a storage location where a website temporarily stores data. When a user requests a piece of information, the website first checks if the data is already in the cache. If it is, it can be served immediately to the user. If not, the new data is fetched and stored in the cache for future use.

By using cache, websites can run faster because the data is retrieved from memory rather than making requests to external sources each time. A cache can be thought of as an in-memory database that stores frequently accessed data.

Types of cache:

• Browser-side cache: This cache is stored in the user’s browser. The benefit is that it doesn’t require server-side configuration, but it can be more complex to manage.
• Server-side cache: Managed and stored by the server, this type of cache is easier to implement and ensures consistent availability to all users.
• Reverse proxy cache: Managed by a reverse proxy server, this type of cache typically resides on a dedicated server acting as an intermediary between the website and users.

How does server-side caching work?

Server-side caching is done at the web server level. It stores frequently accessed content and data so that they are instantly available to users when they revisit the site. This dramatically speeds up the website as the server can deliver the content from memory instead of fetching it from the original source.

Clearing the cache

Both server and browser caches can be cleared. Clearing the cache removes all stored data. This is typically necessary when a website appears outdated because the browser loads a previous version. To fix this, clearing the cache ensures that the latest version is displayed.

In Chrome, you can clear the cache by going to:
Settings > Privacy and Security > Clear Browsing Data.

Common caching mistakes

Common errors related to server-side caching include failing to identify which data and pages should be cached, improperly configuring the caching mechanism, and not verifying if the cache is functioning correctly.

If the cache does not work properly, the following issues may arise:

• Poor user experience: If there is no cache, the website will load slowly.
• Outdated data: If some data is cached and other data is not, users may see outdated information.
• Server overload: If many users request the same data and it’s not cached, the server can become overloaded.

Summary

Server-side caching is an effective performance optimization technique that can greatly enhance the speed of websites and applications. By caching frequently used content, the server load is significantly reduced, and web pages load faster. Careful planning is necessary to determine which parts of the website should be cached and which caching mechanism is most appropriate.