What Is Cached Data

Most consumers expect a website to load within two and three seconds. Any longer, and they could choose to click away to a competitor. They may never come back to your site again. That’s why we need cached data to help improve customer’s online experience.

Cached data is information stored on your computer or device after you visit a website. Developers use cached data to improve your online experience. The goal of cached data is to speed up site loading. Your device won't have a long chit-chat with a server to load all of the text and images and forms on the site. Some of those bits and bytes will be stored in your device.

What is Caching?

In computing, a cache is a high-speed data storage layer which stores a subset of data, typically transient in nature, so that future requests for that data are served up faster than is possible by accessing the data’s primary storage location. Caching allows you to efficiently reuse previously retrieved or computed data.

How Does Cached Data Work?

Think of a cache as a repository of website data you use all the time. Each time you visit that website, your device must pull down that information. If it's stored in the cache, your device skips a step and you save valuable time.

You don't get to choose what fits into the cache. Developers do that work for you based on what they believe offers the fastest load time and the best experience. If you live in an area with spotty internet service, cached data can be a lifesaver. You might wait and wait for an entire site to load. If some of it is cached, you could get the bits you need very quickly. Cached memory isn't the only form of memory your computer uses. In fact, developers use a so-called computer memory hierarchy to describe how most devices store and access data.

Business scenarios and business requirements

Cache data is suitable for business scenarios with "more repeated reads". On the contrary, the meaning of using cache is actually not great, and the hit rate will be very low;

Business requirements determine the requirements for timeliness and directly affect the expiration time and update strategy of the cache. The lower the timeliness requirement, the more suitable for caching. In the case of the same key and the same number of requests, the longer the cache time, the higher the hit rate; In most business scenarios of Internet applications, caching is very suitable.

In summary, the cache has been improved in the following three aspects:

Performance-Store the corresponding data to avoid repeated creation, processing and transmission of data, which can effectively improve performance. For example, cache the unchanged data, such as the country list, which can significantly improve the response speed of the Web program;

Stability-In the same application, it often happens when multiple requests for the same data, logic function and user interface are made. When the user base is large, if each request is processed, the resources consumed are a great waste, and it also causes system instability. For example, in web applications, caching the rendered content of some static pages can effectively save resources and improve stability. And caching data can also reduce the number of accesses to the database, reduce the burden on the database and improve the service capacity of the database;

Availability-Sometimes, the service that provides data information may stop unexpectedly. If caching technology is used, it can still provide support to end users for a certain period of time, which improves the availability of the system.