Russian-doll caching, also known as hierarchical caching, is a caching strategy used in web development and content delivery to improve the performance and reduce the load on web servers. This technique involves caching content in a nested or layered manner, with different cache levels serving as "dolls" nested within each other, similar to traditional Russian nesting dolls (Matryoshka dolls). Each level of the cache contains copies of content at different granularities.
The main idea behind Russian-doll caching is to leverage multiple cache levels to efficiently serve cached content, reducing the need to generate content dynamically from the origin server, which can be resource-intensive. This approach is especially useful for dynamic websites or web applications that generate content based on user requests.
However, implementing Russian-doll caching can be complex, as it requires coordinating multiple cache levels and implementing cache invalidation strategies. Careful planning and management are necessary to ensure that stale or outdated content is not served to users.
This caching strategy is particularly effective for nested content that doesn't change frequently, such as to cache web pages, where each web page contains a variety of sections, images, fonts, style sheets, and components.