Systems and Methods for Efficiently Load Balancing Based on Least Connections

• US 20090034417A1
• Filed: 08/03/2007
• Published: 02/05/2009
• Est. Priority Date: 08/03/2007
• Status: Active Grant

• Current Assignee: Citrix Systems, Inc. (Cloud Software Group)
• Original Assignee: Citrix Systems, Inc. (Cloud Software Group)
• Inventors: Shetty, Anil, Suganthi, Josephine, Kondamuru, Ravi, Bots, Henk
• Granted Patent: US 8,077,622 B2
• Time in Patent Office: Days
• US Class Current: 370/238
• CPC Class Codes: H04L 67/1001 for accessing one among a plurality of replicated servers
• CPC Class Codes: H04L 67/1008 based on parameters of servers, e.g. available memory or workload monitoring of computer activity G06F11/30
• CPC Class Codes: H04L 67/1012 based on compliance of requirements or conditions with available server resources
• CPC Class Codes: H04L 67/1017 based on a round robin mechanism

Abstract

Systems and methods for load balancing services based on fewest connections by decreasing granularity of service selection as a number of fewest connections serviced by the services increases may include establishing, by an appliance, a set of identifiers corresponding to a number of connections serviced by a service, the set comprising a first plurality of identifiers each identifying a predetermined number of connections and a second plurality of identifiers each identifying a predetermined range of numbers of connections. The appliance assigns, to each service servicing connections, an identifier corresponding to the number of connections serviced by the service, at least one of the identifiers selected from the second plurality of identifiers. The appliance receives a request for a service, and forwards the request to a service assigned to the identifier corresponding to a fewest number of connections with at least one service assigned to the identifier.

Claims

1. A method for more efficiently load balancing services based on fewest connections by decreasing granularity of service selection as a number of fewest connections serviced by the services increases, the method comprising:

(a) establishing, by a load balancing appliance, a set of identifiers corresponding to a number of connections serviced by a service, the set comprising a first plurality of identifiers each identifying a predetermined number of connections and a second plurality of identifiers each identifying a predetermined range of numbers of connections;

(b) assigning, by the load balancing appliance to each of a plurality of services servicing connections, an identifier corresponding to the number of connections serviced by the service, at least one of the identifiers selected from the second plurality of identifiers;

(c) receiving, by the appliance, a request for a service;

(d) determining, by the appliance, the identifier corresponding to a fewest number of connections with at least one service assigned to the identifier; and

(e) forwarding, by the appliance, the request to a service identified by the determined identifier.

2. The method of claim 1, wherein the identifiers correspond to a number of active connections serviced.

3. The method of claim 1, wherein each of the second plurality of identifiers identify a predetermined range of connections above a predetermined threshold.

4. The method of claim 1, wherein the second plurality of identifiers each identify a predetermined range of numbers of connections, and at least one range starting at a first number of connections comprises a larger range than at least one range starting at a second, lower, number of connections.

5. The method of claim 4, wherein the at least one range starting at a first number of connections comprises a smaller range than at least one range starting at a second, higher, number of connections.

6. The method of claim 1, wherein step (b) comprises assigning a first service servicing a first number of connections a first identifier selected from the second plurality of identifiers and assigning a second service servicing a second number of connections the first identifier, wherein the first number is different than the second number.

7. The method of claim 1, wherein step (e) comprises forwarding, by the appliance, the request to a service least recently forwarded a request, the service selected from a set of services identified by the determined identifier.

8. The method of claim 1, further comprising forwarding requests to a plurality of services identified by the same identifier in a round-robin manner.

9. The method of claim 1, further comprising determining an updated number of active connections serviced by the service;

and assigning an identifier to the service based on the updated total number.

10. The method of claim 1, further comprising determining an updated number of active connections serviced by a second service;

and assigning an identifier to the second service based on the number of active connections.

11. A load balancing appliance for more efficiently load balancing services based on fewest connections by decreasing granularity of service selection as a number of fewest connections serviced by the services increases, the appliance comprising

a memory element which stores a set of identifiers corresponding to a number of connections serviced by a service, the set comprising a first plurality of identifiers each identifying a predetermined number of connections and a second plurality of identifiers each identifying a predetermined range of numbers of connections

a receiver which receives a request for a service;

a processor in communication with the receiver and the storage element which assigns, to each of a plurality of services servicing connections, an identifier corresponding to the number of connections serviced by the service, at least one of the identifiers selected from the second plurality of identifiers; and

determines an identifier corresponding to the fewest number of connections with at least one service assigned to it; and

a transmitter, in communication with the processor which forwards the request to a service identified by the determined identifier.

12. The system of claim 11, wherein the identifiers correspond to a number of active connections serviced.

13. The system of claim 11, wherein each of the second plurality of identifiers identify a predetermined range of connections above a predetermined threshold.

14. The system of claim 11, wherein the second plurality of identifiers each identify a predetermined range of numbers of connections, and at least one range starting at a first number of connections comprises a larger range than at least one range starting at a second, lower, number of connections.

15. The system of claim 14, wherein the at least one range starting at a first number of connections comprises a smaller range than at least one range starting at a second, higher, number of connections.

16. The system of claim 11, wherein the processor assigns a first service servicing a first number of connections a first identifier selected from the second plurality of identifiers and assigning a second service servicing a second number of connections the first identifier, wherein the first number is different than the second number.

17. The system of claim 11, wherein the transmitter forwards the request to a service least recently forwarded a request, the service selected from a set of services identified by the determined identifier.

18. The system of claim 11, wherein the transmitter forwards requests to a plurality of services identified by the same identifier in a round-robin manner.

19. The system of claim 11, wherein the processor determines an updated number of active connections serviced by the service;

and assigns an identifier to the service based on the updated total number.

20. The system of claim 11, wherein the processor determines an updated number of active connections serviced by a second service;

and assigns an identifier to the second service based on the number of active connections.