Caching refers to the process of temporarily storing frequently used data or resources in a cache memory or storage location in order to speed up subsequent access to that data. Cache is often used to reduce latency and improve efficiency by reducing the amount of time it takes to access data.
For example, web browsers typically use caching to store website content such as images, videos, and text files on the user’s device so they don’t have to redownload the same content every time they visit the site. This reduces the amount of data that needs to be transferred over the internet, resulting in faster page load times and a better browsing experience. Another example is caching in computer processors, where frequently accessed data is stored in a small high-speed memory cache to avoid accessing slower main memory. This helps to speed up processing and improve overall performance.
Caching refers to the process of storing frequently accessed data in a temporary storage area, such as memory or disk, to reduce data retrieval time.
The purpose of caching is to improve performance, scalability, and availability of applications by reducing data access latency, network traffic and server load.
The two main types of caching are client-side caching and server-side caching.
Client-side caching uses web browser caching or proxy caching to store frequently accessed web pages, images, scripts, and stylesheets on the user’s local machine.
Server-side caching uses a caching layer, such as Memcached or Redis, to store frequently accessed data, such as session data, database queries, or API responses, in memory.
Cache invalidation is the process of removing or updating cached data when the source data changes or expires.
Cache expiration policies, such as time-based or event-based invalidation, determine when cached data should be removed or refreshed.
Cache invalidation and expiration can be challenging, as it requires coordination between multiple layers of the application stack and may result in stale or inconsistent data.
Despite its challenges, caching is a critical technique for optimizing web performance and enabling high-traffic, high-volume applications.
What is cache coherence?
Answer: Cache coherence refers to the consistency of data across multiple caches in a distributed system. It ensures that multiple copies of the same data are kept up-to-date and synchronized across all caches.
What is cache hit ratio?
Answer: Cache hit ratio measures the percentage of requests that are served from the cache rather than from the original data source. A high hit ratio indicates efficient caching and faster response times.
What is cache invalidation?
Answer: Cache invalidation is the process of removing or updating cached data when it becomes stale or outdated. This ensures that users are always seeing the most up-to-date information and prevents data integrity issues.
What is cache warming?
Answer: Cache warming is the process of preloading frequently accessed data into a cache before it is requested. This can reduce latency and ensure that the data is readily available to users when they need it.
What is caching sharding?
Answer: Caching sharding is the process of partitioning cached data across multiple cache servers to improve scalability and performance. This allows for better load balancing and reduces the risk of data loss in case of server failures.