Queuing model for a plurality of servers

• US 20030182261A1
• Filed: 02/14/2003
• Published: 09/25/2003
• Est. Priority Date: 02/15/2002
• Status: Active Grant

• Current Assignee: International Business Machines Corporation
• Original Assignee: International Business Machines Corporation
• Inventors: Patterson, James Edmund
• Granted Patent: US 7,333,974 B2
• Time in Patent Office: Days
• US Class Current: 707/1
• CPC Class Codes: H04L 67/1001 for accessing one among a plurality of replicated servers
• CPC Class Codes: H04L 67/1012 based on compliance of requirements or conditions with available server resources
• CPC Class Codes: H04L 67/1023 based on a hash applied to IP addresses or costs
• CPC Class Codes: H04L 67/1036 Load balancing of requests to servers for services different from user content provisioning, e.g. load balancing across domain name servers
• CPC Class Codes: Y10S 707/99932 Access augmentation or optimizing
• CPC Class Codes: Y10S 707/99933 Query processing, i.e. searching
• CPC Class Codes: Y10S 707/99953 Recoverability

Abstract

The current invention provides a system and method for queuing and distributing requests to one or more query servers. The system contains a first tier queue associated with a server based mechanism for directing service requests to a second tier queue associated with each of the one or more query servers. The current invention provides a “pull” model for the distribution of an initial service request of a query containing two or more service requests. Subsequent service requests from this query are assigned to a query server without being placed in a first tier queue. These subsequent service requests are placed directly in the queue of the query server that handled the previous service request from the same query.

Claims

1. A system for the distribution of service requests to one or more query servers that are suitable for fulfilling the service requests, the system being operable on a plurality of servers, the system comprising:

an interface component, the interface component being;

suitable for operation on the plurality of servers, suitable to determine if the service request is to be directed to a pre-identified query server and suitable for distributing the service request to either the pre-identified query server or a query server available to accept the service request; and

a first server based mechanism for receiving information related to the at least one query server, the server based mechanism communicating with the interface component and directing the interface component in the distribution of service requests.

2. A system according to claim 1 further comprising a second server based mechanism, the second server based mechanism collecting information related to the operation of the query servers, the second server based mechanism communicating the collected information to the first server based mechanism.

3. A system according to claim 1 wherein the first server based mechanism comprises a queue appropriate for maintaining service requests.

4. A system for the provision of information from a database to a client that provides a service request requesting information, the system comprising:

an interface component, the interface component being;

suitable for operation on the plurality of servers, suitable to determine if the service request is to be directed to a pre-identified query server and suitable for distributing the service request to either the pre-identified query server or a query server available to accept the service request;

one or more query servers, the one or more query servers being suitable for receiving service requests from the interface component and being suitable for the provision of information requested in the service requests;

a first server based mechanism for receiving information related to the at least one query server, the server based mechanism with the interface component and directing the interface component in the distribution of service requests; and

a first server, the first server being suitable for the operation of the first server based mechanism thereon and being suitable for communication with the interface component.

5. A system according to claim 4 wherein the first server comprises a queue appropriate for maintaining service requests.

6. A system according to claim 4 wherein the one or more query servers comprise a queue appropriate for maintaining service requests.

7. A system according to claim 4 further comprising:

a second server based mechanism, the second server based mechanism being suitable for collecting information related to the operation of the query servers and providing this information to the first server based mechanism.

8. A system according to claim 7 wherein the first server comprises a queue appropriate for maintaining service requests.

9. A system according to claim 7 wherein the one or more query servers comprise a queue appropriate for maintaining service requests.

10. A method or routing a service request to a query server, the query server being elements of a system for the distribution of service requests containing one or more query servers, the system further comprising an interface component for interfacing between a source of service requests and the query servers of the system and a mechanism for directing service requests, the method comprising the steps of:

invoking of the interface component by the source of service requests upon the receipt of a service request;

routing of service requests by the interface component to either the mechanism for directing service requests or a query server;

monitoring of the interface component by the mechanism for directing service requests; and

monitoring of the one or more query servers or notification from the query servers regarding the status of the query servers.

11. A method of routing service requests by the interface component, the method comprising the steps of:

interrogating a service request to determine if a server identification parameter is included with the service request;

forwarding identification information related to the service request to the mechanism for directing service requests if the service request does not have a server identification parameter included with it;

receiving a query server identification for a query server that is available for accepting the service request;

forwarding of the service request to the query server identified by the query server identification; and

forwarding the service request to the query server identified in the server identification parameter if the service request has a server identification parameter included with it.

12. A method of monitoring an interface component by the mechanism for directing service requests, the method comprising the steps of:

waiting to receive a service request from the interface component, the interface component providing an interface between a source of service requests and . . . ;

receiving a service request from the interface component, the interface component providing an interface between a source of service requests and . . . ;

determining if a query server is available for the acceptance of a service request for the provision of information thereto;

placing the service request in a queue associated with the mechanism for directing service requests if there is no query server available to accept the service request; and

forwarding the service request and query server identification related to the query server that is able to accept the service request to the interface component if a query server was determined to be available to accept the service request.

13. A method of monitoring one or more query servers by the mechanism for directing one or more service requests to query servers for notification from the query servers regarding the status of the query servers, the method comprising the steps of:

waiting for a notification related to the query server status;

receiving a notification related to the query server status;

determining if the query server that provided a notification related is available or unavailable to accept the service request;

determining if service requests are waiting for a query server to become available to accept a service request, if a query server has become available to accept a service request;

dequeuing a service request from the queue associated with the mechanism for directing service requests, if a service request is waiting for a query server to become available to accept a service request;

forwarding the service request and query server identification related to the query server that is able to accept the service request to the interface component;

marking the available query server as available if there are no service request is waiting for a query server to become available to accept a service request; and

marking the unavailable query server as unavailable if a query server has indicated it is unavailable to accept a service request.