SYSTEM AND METHOD TO MAINTAIN COHERENCE OF CACHE CONTENTS IN A MULTI-TIER SOFTWARE SYSTEM AIMED AT INTERFACING LARGE DATABASES

摘要

A method and a system for maintaining coherence of cache contents in a multi-tiered architecture of servers are described. This includes a front tier ofsatellite servers, each operating a local cache, and a middle tier of centralservers each operating a central cache. Central servers interface withdatabases through database servers to retrieve the data elements used toconstruct objects and store them in central caches. Once constructed, objectsare attributed a time-to-live (TTL) and stored in central caches then,forwarded to the satellite servers where they are stored in local cachesbefore being delivered to the software applications that have requested them.They are invalidated when outdated and reconstructed from a central serverfrom where they are forwarded to all central caches and to the local cacheswhere they are needed.