Shared Caching Server ETag Validation for Dynamic Content
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Conventional shared caching systems are inefficient in handling dynamic web content, as they rely on time-based caching approaches, leading to rapid expiration of cached web pages for frequently changing content, which results in increased server load and reduced caching benefits.
Innovation Solution
A system utilizing Hypertext Transfer Protocol (HTTP) entity tags (ETags) or other validation headers to differentiate user types and determine the currency of cached content, allowing for the serving of either cached or updated content based on user type, thereby optimizing caching and reducing server load.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Ease of manufacture
If time-based caching approach is used, then caching implementation is simple, but cached content expires quickly for dynamic content
Solution Approach 1:
The patent changes the caching parameter from time-based to validation header-based. Instead of using a fixed time duration to determine cache validity, the system uses validation headers (ETags) that provide content-specific validity information. This allows the cache to store dynamic content for extended periods while ensuring content freshness through validation mechanisms, resolving the contradiction between simple implementation and extended content validity.
2Reliability
If cached content is frequently invalidated, then content currency is maintained, but server load increases
Solution Approach 1:
The patent implements partial validation by using validation headers to selectively invalidate only the specific content that has changed, rather than invalidating all cached content. The validation header mechanism allows the system to check only the necessary content validity, reducing unnecessary server requests while maintaining content currency for changed content.
Solution Approach 2:
The system uses validation headers as a feedback mechanism where the server provides validity information about cached content. This feedback allows the cache to determine whether content is still valid without requiring full content retransmission, reducing server load while maintaining content currency through efficient validation.
3Reliability
If validation headers are used to track content changes, then content freshness is ensured, but caching system complexity increases
Solution Approach 1:
The patent applies validation headers (ETags) that serve multiple functions: they track content changes, enable cache validation, and provide content identification. This multi-functionality ensures content freshness while avoiding the need for separate tracking mechanisms, thereby limiting the increase in system complexity.
Data Source
AI summary
A web server and a shared caching server are described for serving dynamic content to users of at least two different types, where the different types of users receive different versions of the dynamic content. A version of the dynamic content includes a validation header, such as an ETag, that stores information indicative of the currency of the dynamic content and information indicative of a user type for which the version of the dynamic content is intended. In response to a user request for the dynamic content, the shared caching server sends a validation request to the web server with the validation header information. The web server determines, based on the user type of the requestor and/or on the currency of the cached dynamic content whether to instruct the shared caching server to send the cached content or to send updated content for serving to the user.