International Business Machines Corporation

Vsevolod V Panteleenko

Trent Ray Jaeger

Nayeem Islam

Jochen Liedtke

A server complex including at least one hit server with item cache, used to process read and write operations relating to cached items from clients, and at least one miss server, serving as a link to other servers (e.g., web servers, file system servers, and databases) for receiving requests relayed from the hit server(s) which relate to non-cached items and for responding to same. The hit server is a general-purpose, generic, component, which is independent of concrete applications and is basically responsible for the performance; while a miss server is a highly-customizable component, which is responsible for flexibility, and is application specific. The inventive architecture provides improved performance whereby a server complex achieves exceptionally high throughput rates for local services (i.e., services using items in the local item cache); flexibility, whereby a server complex can support the enforcement of a variety of application-specific policies for item management, authentication, and item consistency; security, whereby a server complex can enable the verification of the source, integrity, and freshness of communications over untrusted links; and, scalability, whereby a server complex is expandable by adding server components and implementing customized item consistency policies.

Powerful and flexible server architecture

A cache system in accordance with the present invention consists of one or more cache components and a set of one or more consistency-replacement functions. A cache component caches one or more items in its one or more cache entries. Items that hit in the cache can result in corresponding cache entries being read or written. Any valid entry in a cache component includes status information reflecting whether the entry has been accessed and whether it has been modified, and is linked to a consistency-action matrix that, in correspondence with the entry's status information and access type (i.e. read or write), determines what consistency action has to be executed in conjunction with the current entry access. Consistency actions and the consistency-action matrix are the inventive mechanisms for implementing cache-coherency and cache-replacement policies. Any valid entry in a cache is linked to a consistency-replacement function that implements one or more consistency and/or replacement policies. Consistency-replacement functions are application-specific and are implemented by means of the consistency-action matrix.

Flexible cache-coherency mechanism

A cache system in accordance with the present invention consists of one or more cache components and a set of one or more consistency-replacement functions. A cache component caches one or more items in its one or more cache entries. Items that hit in the cache can result in corresponding cache entries being read or written. Any valid entry in a cache component includes status information reflecting whether the entry has been accessed and whether it has been modified, and is linked to a consistency-action matrix that, in correspondence with the entry's status information and access type (i.e. read or write), determines what consistency action has to be executed in conjunction with the current entry access. consistency actions and the consistency-action matrix are the inventive mechanisms for implementing cache-coherency and cache-replacement policies. Any valid entry in a cache is linked to a consistency-replacement function that implements one or more consistency and/or replacement policies. Consistency-replacement functions are application-specific and are implemented by means of the consistency-action matrix.

Growing community of inventors

North White Plains, NY, United States of America

Vsevolod V Panteleenko