Routing client requests to back-end servers

• US 7,657,638 B2
• Filed: 11/23/2004
• Issued: 02/02/2010
• Est. Priority Date: 10/04/2000
• Status: Expired due to Fees

• Current Assignee: Microsoft Technology Licensing LLC (Microsoft Corporation)
• Original Assignee: Microsoft Corporation
• Inventors: Deen, Brian, Soderberg, Joel, Hopmann, Alex
• Primary Examiner(s): VAUGHN JR, WILLIAM C
• Assistant Examiner(s): Delgado; Michael
• Application Number:
  US10/998,240
• Publication Number:
  US 20050086347A1
• Time in Patent Office: 1,897 Days
• Field of Search: 709/229, 709/218, 709/244, 718/105
• 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. A front-end server interconnected with a communication link to a client system and a plurality of back-end servers, the front-end server providing access to content stored at a particular back-end server such that the client system does not need to know which of the plurality of back-end servers store the content, the front-end server comprising:

one or more processors that execute computer-executable instructions; and

one or more computer readable media with computer-executable instructions to be executed by the one or more processors, the computer-executable instructions comprising;

computer-executable instructions for 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;

computer-executable instructions for examining a global catalog that dynamically maps the resource identifier to a plurality of back-end servers storing the requested content;

computer-executable instructions for identifying a particular back-end server storing the requested content, from the plurality of back-end servers mapped to the resource identifier 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

computer-executable instructions for directing the request to the particular back-end server.

2. A front-end server as recited in claim 1, wherein the computer-executable instructions further comprise:

computer-executable instructions for receiving the requested content from the particular back-end server; and

computer-executable instructions for sending the requested content to the client system.

3. A front-end server as recited in claim 1, wherein the content is specific to a user at the client system and is stored only at the particular back-end server.

4. A front-end server as recited in claim 1, wherein the computer-executable instructions further comprise:

computer-executable instructions for requesting authentication credentials for a user at the client system; and

computer-executable instructions for receiving proper authentication credentials from the user at the client system.

5. A front-end server as recited in claim 4, wherein the computer-executable instructions further comprise computer-executable instructions for adding at least a portion of the authentication credentials to the resource identifier so that the resource identifier is limited to a user associated with the authentication credentials.

6. A front-end server as recited in claim 4, wherein the particular back-end server requires user authentication, and wherein the computer-executable instructions further comprise computer-executable instructions for including the user authentication credentials with the request for content directed to the particular back-end server.

7. A front-end server as recited in claim 4, wherein the computer-executable instructions further comprise:

computer-executable instructions for receiving from the global catalog an authentication token associated with the authentication credentials; and

computer-executable instructions for using the authentication token as a key for a hash operation to identify the particular back-end server.

8. A front-end server as recited in claim 1, wherein the computer-executable instructions further comprise:

computer-executable instructions for receiving a subsequent request for the content from the client system, the request including the same resource identifier as the prior request;

computer-executable instructions for examining the global catalog for the subsequent request; and

computer-executable instructions for identifying the same particular back-end server that was identified for the prior request.

9. A front-end server as recited in claim 1, wherein the computer-executable instructions further comprise:

computer-executable instructions for receiving a subsequent request for the content from the client system, the request including the same resource identifier as the prior request;

computer-executable instructions for examining the global catalog for the subsequent request; and

computer-executable instructions for identifying a different back-end server from the particular back-end server identified for the prior request because the particular back-end server is either unavailable or no longer stores the requested content.

10. A front-end server as recited in claim 1, wherein the content is email content.

11. A front-end server as recited in claim 1, wherein the front-end server is part of a hosting system and is identified by a plurality of server names, and wherein the global catalog dynamically maps resource identifiers referencing the front-end server based at least in part on a server name portion of the resource identifier.

12. A front-end server interconnected with a communication link to a client system and one or more back-end servers, the front-end server providing access to content stored at a particular back-end server such that the client system does not need to know which of the one or more back-end servers store the content, the front-end server comprising:

one or more processors that execute computer-executable instructions;

one or more computer readable media with computer-executable instructions to be executed by the one or more processors, the computer-executable instructions comprising;

computer-executable instructions for 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;

computer-executable instructions for checking the request to insure that the request is a valid request;

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

computer-executable instructions for 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

computer-executable instructions for directing the request to the particular back-end server.

13. A front-end server as recited in claim 12, wherein the content is Web content.

14. A front-end server as recited in claim 12, wherein the computer-executable instructions further comprise:

computer-executable instructions for requesting authentication credentials from the client system;

computer-executable instructions for receiving proper authentication credentials from the client system; and

computer-executable instructions for including the authentication credentials with the request for content directed to the particular back-end server

15. A front-end server as recited in claim 14, wherein the computer-executable instructions further comprise:

computer-executable instructions for receiving from the global catalog an authentication token associated with the authentication credentials; and

computer-executable instructions for using the authentication token as a key for a hash operation to identify the particular back-end server.

16. A front-end server interconnected with a communication link to a client system and a plurality of back-end servers, the front-end server providing access to content stored at a particular back-end server such that the client system does not need to know which of the plurality of back-end servers store the content, the front-end server comprising:

one or more processors that execute computer-executable instructions;

one or more computer readable media with computer-executable instructions to be executed by the one or more processors, the computer-executable instructions comprising;

computer-executable instructions for 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;

computer-executable instructions for mapping a request received from the client system to a particular one of a plurality of back-end servers that store the requested content, wherein a given request maps to the same particular back-end server over time, as long as the same particular back-end server is available and stores the content being requested;

computer-executable instructions for retrieving the requested content from the particular back-end server; and

computer-executable instructions for sending the requested content to the client system.

17. A front-end server as recited in claim 16, wherein the computer-executable instructions further comprise computer-executable instructions for validating the request.

18. A front-end server as recited in claim 16, wherein the computer-executable instructions further comprise:

computer-executable instructions for authenticating the client system; and

computer-executable instructions for distributing the request to the particular back-end server based on the client system authentication.

19. A front-end server as recited in claim 18, wherein the computer-executable instructions further comprise computer-executable instructions for altering the resource identifier based on the client system authentication in order to authenticate the client system to the particular back-end server.

20. A front-end server as recited in claim 16, wherein the computer-executable instructions further comprise computer-executable instructions for hosting a plurality of back-end servers identified by a plurality of server names at the front-end server.