Load balancing technique implemented in a data network device utilizing a data cache

• US 20090150534A1
• Filed: 02/07/2009
• Published: 06/11/2009
• Est. Priority Date: 05/11/1999
• Status: Active Grant

• Current Assignee: JUNE RAY LIMITED
• Original Assignee: IpVenture, Inc.
• Inventors: Mayya, Ajit Ramachandra, Miller, Andrew Karl, Menendez, Jack Dee
• Granted Patent: US 7,930,416 B2
• Time in Patent Office: Days
• US Class Current: 709/223
• CPC Class Codes: G06F 16/9574 of access to content, e.g. by caching
• CPC Class Codes: G06Q 10/06 Resources, workflows, human or project management; Enterprise or organisation planning; Enterprise or organisation modelling
• CPC Class Codes: G06Q 10/06311 Scheduling, planning or task assignment for a person or group
• CPC Class Codes: G06Q 10/06312 Adjustment or analysis of established resource schedule, e.g. resource or task levelling, or dynamic rescheduling
• CPC Class Codes: G06Q 10/06315 Needs-based resource requirements planning or analysis
• CPC Class Codes: G06Q 10/06316 Sequencing of tasks or work
• CPC Class Codes: G06Q 10/08 Logistics, e.g. warehousing, loading or distribution; Inventory or stock management
• CPC Class Codes: G06Q 10/08355 Routing methods
• CPC Class Codes: G06Q 10/087 Inventory or stock management, e.g. order filling, procurement or balancing against orders
• CPC Class Codes: G06Q 20/203 Inventory monitoring
• CPC Class Codes: G06Q 30/0201 Market modelling; Market analysis; Collecting market data
• CPC Class Codes: G06Q 30/06 Buying, selling or leasing transactions
• CPC Class Codes: G06Q 30/0601 Electronic shopping [e-shopping]
• CPC Class Codes: G06Q 30/0633 Lists, e.g. purchase orders, compilation or processing
• CPC Class Codes: G06Q 30/0641 Shopping interfaces
• CPC Class Codes: H04L 67/1097 for distributed storage of data in networks, e.g. transport arrangements for network file system [NFS], storage area networks [SAN] or network attached storage [NAS]

Abstract

Techniques for implementing a load balanced server system are described which may be used for effecting electronic commerce over a data network. The system comprises a load balancing system and a plurality of servers in communication with the load balancing system. Each of the plurality of servers may include a respective data cache for storing state information relating to client session transactions conducted between the server and a particular client. The load balancing system can be configured to select, using a load balancing protocol, an available first server from the plurality of servers to process an initial packet received from a source device such as, for example, a client machine of a customer. The load balancing system can also configured to route subsequent packets received from the source device to the first server. Before generating its response, the first server may verify that the state information relating to a specific client session stored in the data cache is up-to-date. If the first server determines that the state information stored in the data cache is not up-to-date, then the first server may be configured to retrieve the desired up-to-date state information from a database which is configured to store all state information relating to client sessions which have been initiated with the server system.

Claims

1. A computer-implemented method for effecting electronic commerce over a data network, the method comprising:

receiving an initial block of data from a device;

assigning the initial block of data from the device to a first server of a multi-server system, where load balancing is performed, and which includes at least a second server, with the first server supporting a plurality of products available for purchase from an on-line merchant, with the first server using a first data cache and a database, and with the second server using a second data cache and the database, wherein a session between the device and the first server is initiated;

storing information associated with the session in both the first data cache and the database, the information associated with the session including an identifier for the session;

generating a response to the initial block of data at the first server, with the response including information associated with the session;

transmitting the response to the device;

causing a subsequent block of data received from the device to be routed to the first server, with information related to the subsequent block of data stored in both the first data cache and the database, and with such information being stored as associated with the session, wherein at least a portion of the subsequent block of data is related to purchasing a product from the plurality of products via an electronic shopping cart;

detecting a cache miss with respect to retrieving information associated with the session; and

retrieving information associated with the session from the database into one of the data caches in view of the cache miss for use by the corresponding server.

2. A method as recited in claim 1,

wherein the first and the second servers include substantially similar content, and

wherein the content on each server includes a plurality of addresses to enable accessing information via that server.

3. A method as recited in claim 1 wherein the first server is further configured or designed to provide at least one address specific to the first server in the response to enable accessing information via the first server.

4. A method as recited in claim 3 wherein the address is a Uniform Resource Locator.

5. A method as recited in claim 1 wherein a block of data from the device is related to requesting a product to be added to the electronic shopping cart.

6. A method as recited in claim 1,

wherein the response includes information related to a server identifier configured to identify the corresponding server,

wherein the subsequent block of data received from the device includes information related to the server identifier,

wherein the first server is further configured or designed to compare the information related to the server identifier received from the device with information related to the server identifier accessed from the first server, and

wherein the first server is further configured or designed to flush at least a portion of the first data cache due to information related to the server identifier received from the device being different from the information related to the server identifier accessed from the first server.

7. A method as recited in claim 1,

wherein the response includes information related to a server identifier configured to identify the corresponding server, and

wherein the information related to the server identifier accessed from the corresponding server changes if the corresponding server is rebooted or recovers from a failure.

8. A method as recited in claim 1 further comprising:

testing the first server for failure, and

if the first server fails,

causing a subsequent block of data received from the device to be routed, instead of to the first server, to the second server, and

retrieving information associated to the session from the database to be stored in the second data cache for use by the second server.

9. A method as recited in claim 1, where the one of the data caches is the first data cache, and the corresponding server is the first server.

10. A method as recited in claim 1, where the one of the data caches is the second data cache, and the corresponding server is the second server.

11. A computer readable medium comprising a plurality of instructions for effecting electronic commerce over a data network, the plurality of instructions, when executed by a computing device, result in the computing device:

receiving an initial block of data from a device;

assigning the initial block of data from the device to a first server of a multi-server system, where load balancing is performed, and which includes at least a second server, with the first server supporting a plurality of products available for purchase from an on-line merchant, with the first server using a first data cache and a database, and with the second server using a second data cache and the database, wherein a session between the device and the first server is initiated;

storing information associated with the session in both the first data cache and the database, the information associated with the session including an identifier for the session;

generating a response to the initial block of data at the first server, with the response including information associated with the session;

transmitting the response to the device;

causing a subsequent block of data received from the device to be routed to the first server, with information related to the subsequent block of data stored in both the first data cache and the database, and with such information being stored as associated with the session, wherein at least a portion of the subsequent block of data is related to purchasing a product from the plurality of products via an electronic shopping cart;

detecting a cache miss with respect to retrieving information associated with the session; and

retrieving information associated with the session from the database into one of the data caches in view of the cache miss for use by the corresponding server.

12. A computer readable medium as recited in claim 11,

wherein the first and the second servers include substantially similar content, and

wherein the content on each server includes a plurality of addresses to enable accessing information via that server.

13. A computer readable medium as recited in claim 11 wherein the first server is further configured or designed to provide at least one address specific to the first server in the response to enable accessing information via the first server.

14. A computer readable medium as recited in claim 13 wherein the address is a Uniform Resource Locator.

15. A computer readable medium as recited in claim 11 wherein a block of data from the device is related to requesting a product to be added to the electronic shopping cart.

16. A computer readable medium as recited in claim 11,

wherein the response includes information related to a server identifier configured to identify the corresponding server,

wherein the subsequent block of data received from the device includes information related to the server identifier,

wherein the first server is further configured or designed to compare the information related to the server identifier received from the device with information related to the server identifier accessed from the first server, and

wherein the first server is further configured or designed to flush at least a portion of the first data cache due to information related to the server identifier received from the device being different from the information related to the server identifier accessed from the first server.

17. A computer readable medium as recited in claim 11,

wherein the response includes information related to a server identifier configured to identify the corresponding server, and

wherein the information related to the server identifier accessed from the corresponding server changes if the corresponding server is rebooted or recovers from a failure.

18. A computer readable medium as recited in claim 11, wherein the plurality of instructions, when executed by the computing device, further result in the computing device:

testing the first server for failure, and

if the first server fails,

causing a subsequent block of data received from the device to be routed, instead of to the first server, to the second server, and

retrieving information associated to the session from the database to be stored in the second data cache for use by the second server.

19. A computer readable medium as recited in claim 11, where the one of the data caches is the first data cache, and the corresponding server is the first server.

20. A computer readable medium as recited in claim 11, where the one of the data caches is the second data cache, and the corresponding server is the second server.