Routing client requests to back-end servers

• US 20050086347A1
• Filed: 11/23/2004
• Published: 04/21/2005
• Est. Priority Date: 10/04/2000
• Status: Active Grant

• Current Assignee: Microsoft Technology Licensing LLC (Microsoft Corporation)
• Original Assignee: Microsoft Corporation
• Inventors: Hopmann, Alex, Deen, Brian, Soderberg, Joel
• Granted Patent: US 7,657,638 B2
• Time in Patent Office: Days
• US Class Current: 709/229
• CPC Class Codes: G06F 16/10 File systems; File servers
• CPC Class Codes: H04L 61/30 Managing network names, e.g. use of aliases or nicknames name-to-address mapping H04L61/45
• CPC Class Codes: H04L 61/301 Name conversion
• CPC Class Codes: H04L 63/08 for authentication of entities cryptographic mechanisms or cryptographic arrangements for entity authentication H04L9/32
• CPC Class Codes: H04L 67/1001 for accessing one among a plurality of replicated servers
• CPC Class Codes: H04L 67/1014 based on the content of a request
• CPC Class Codes: H04L 67/1023 based on a hash applied to IP addresses or costs
• CPC Class Codes: H04L 67/56 Provisioning of proxy services store-and-forward switching systems in data switching networks H04L12/54
• CPC Class Codes: H04L 67/567 Integrating service provisioning from a plurality of service providers
• CPC Class Codes: H04L 67/63 Routing a service request depending on the request content or context

Abstract

Methods and computer program products for using a front-end server to access content stored on one or more back-end servers. The front-end server receives requests for content from client systems. Back-end servers store the content, but to the client system, it appears as if the front-end server is the content'"'"'s source. Upon receiving the request, the front-end server checks the validity of the request and examines a global catalog that dynamically maps client system requests to the back-end server or servers that store the requested content. In some circumstances, the content will be stored at a single back-end server and the front-end server directs the request to that server. Alternatively, a list of back-end servers storing the requested content may be generated. If so, the front-end then uses an authentication token as a key to a hash operation that is performed on the list and a single server that is capable of satisfying the request for content is identified. A given request and authentication token always identify the same server if the list of servers available for providing the requested content remains the same. The front-end server provides a single source for content requests so that client systems are not required to alter requests or invalidate local caches when content is moved from one back-end server to another. The front-end server also provides an additional level of security for back-end servers.

Claims

1. In a computerized system that includes a client system, a front-end server, and one or more back-end servers, all interconnected with a communication link, wherein over time content may be moved from one back-end server to another or may appear to be stored at a back-end server when in fact the content is not stored at that back-end server, a method of accessing content stored at a particular back-end server such that the client system does not know which of the one or more back-end servers store the content, the method comprising the front-end server performing the acts of:

receiving a request for the content from the client system, the request including a resource identifier that references the front-end server and the content being requested by the client system;

examining a global catalog that dynamically maps resource identifiers to the one or more back-end servers storing the content;

identifying a particular back-end server storing the requested content based on the mappings in the global catalog, wherein the same particular back-end server is identified for a given request over time, as long as the same particular back-end server is available and stores the content being requested; and

directing the request to the particular back-end server.