DNS Resolver Functional Cache for Context-Aware Query Processing

The patent segments the DNS caching function into two distinct components: a traditional DNS cache for storing resource records with standard TTLs, and a separate functional cache for storing executable code and data structures (like the trie structure) that enable adaptive query processing. This segmentation allows each cache to be optimized independently - the traditional cache maintains small size while the functional cache stores reusable processing logic, thereby reducing overall memory usage while improving response times through efficient query processing.

The patent implements preliminary action by pre-compiling domain name patterns, regex expressions, and resolution rules into a trie data structure and associated code during an offline preparation phase. This pre-processed functional cache enables the DNS resolver to quickly evaluate queries against predetermined patterns without performing complex computations in real-time, significantly reducing response time while keeping the cached data compact.

The patent creates a copy of the functional cache (trie structure and processing code) at the recursive DNS resolver, eliminating the need for the authoritative name server to process every query. The functional cache is replicated and stored locally, enabling the resolver to independently evaluate queries against cached patterns and rules, thereby distributing the processing load and reducing authoritative server burden while maintaining data freshness through periodic updates.

The patent enables self-service by allowing the recursive DNS resolver to autonomously process queries using its local functional cache, without requiring continuous interaction with the authoritative name server. The resolver independently evaluates queries against cached patterns, performs substitutions, and generates responses, only contacting the authoritative server when necessary (e.g., for cache misses or updates), thereby reducing server load while maintaining reliability.

The patent applies parameter changes by transforming complex context-dependent query evaluation into a structured process that manipulates parameters within a predefined framework. The trie structure organizes domain patterns with associated substitution parameters, and the resolution process systematically evaluates these parameters against query components. This parameterized approach enables accurate context-dependent responses while keeping the resolver logic manageable through structured data representation rather than complex conditional programming.

The patent introduces an intermediary layer - the functional cache containing the trie structure and substitution rules - that mediates between the raw query and the resolution process. This intermediary pre-compiled structure translates complex context-dependent matching logic into efficient pattern evaluation and parameter substitution operations, improving query accuracy while shielding the resolver from the complexity of implementing sophisticated pattern matching algorithms from scratch.