SYSTEMS AND METHODS FOR LOAD BALANCING VIA A PLURALITY OF VIRTUAL SERVERS UPON FAILOVER USING METRICS FROM A BACKUP VIRTUAL SERVER

• US 20090300407A1
• Filed: 05/29/2008
• Published: 12/03/2009
• Est. Priority Date: 05/29/2008
• Status: Active Grant

• Current Assignee: Citrix Systems, Inc. (Cloud Software Group)
• Original Assignee: Citrix Systems, Inc. (Cloud Software Group)
• Inventors: Raja, Murali, Shetty, Anil, Kamath, Sandeep, Verzunov, Sergey, Suganthi, Josephine
• Granted Patent: US 8,065,559 B2
• Time in Patent Office: Days
• US Class Current: 714/4
• CPC Class Codes: G06F 9/505 considering the load
• 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 67/101 based on network conditions
• CPC Class Codes: H04L 67/1012 based on compliance of requirements or conditions with available server resources
• CPC Class Codes: H04L 67/1029 using data related to the state of servers by a load balancer
• CPC Class Codes: H04L 67/1034 Reaction to server failures by a load balancer

Abstract

The present invention provides methods and systems for performing load balancing via a plurality of virtual servers upon a failover using metrics from a backup virtual server. The methods and systems described herein provide systems and methods for an appliance detecting that a first virtual server of a plurality of virtual servers having one or more backup virtual servers load balanced by an appliance is not available, identifying at least a first backup virtual server of a one or more backup virtual servers of the first virtual server is available, maintaining a status of the first virtual server as available in response to the identification, obtaining one or more metrics from the first backup virtual server of a one or more backup virtual servers, and determining the load across the plurality of virtual servers using the metrics obtained from the first backup virtual server associated with the first virtual server.

Claims

1. A method of performing load balancing via a plurality of virtual servers upon a failover using metrics from a backup virtual server, the method comprising the steps of:

(a) detecting, by an appliance, that a first virtual server of a plurality of virtual servers load balanced by an appliance is not available, the first virtual server having one or more backup virtual servers;

(b) identifying, by the appliance, that at least a first backup virtual server of a one or more backup virtual servers of the first virtual server is available;

(c) maintaining, by the appliance, a status of the first virtual server as available in response to the identification;

(d) obtaining, by the appliance, one or more metrics from the first backup virtual server of a one or more backup virtual servers; and

(e) determining, by the appliance, the load across the plurality of virtual servers using the metrics obtained from the first backup virtual server associated with the first virtual server.

2. The method of claim 1, comprising identifying, by the appliance, the first virtual backup server is unavailable, and obtaining, by the appliance, metrics from the second backup virtual server.

3. The method of claim 2, comprising determining, by the appliance, the load across the second backup virtual server and the plurality of virtual servers using the metrics obtained from the second backup virtual server.

4. The method of claim 2, comprising determining, by the appliance, one of the load across the second backup virtual server or the load across the plurality of virtual servers using the metrics obtained from the second backup virtual server.

5. The method of claim 1, comprising identifying, by the appliance, that the first virtual server is available.

6. The method of claim 5, comprising determining, by the appliance, the load across the plurality of virtual servers using the metrics obtained from the first backup virtual server.

7. The method of claim 5, comprising continuing, by the appliance, to transmit requests directed to the first virtual server to the one of the first backup virtual server or the first virtual server.

8. The method of claim 1, wherein step (e) comprising determining, by the appliance, the load across the plurality of virtual servers using metrics from one or more of a plurality of backup virtual servers.

9. The method of claim 1, wherein step (f) comprises determining, by a global load balancing virtual server of the appliance, the load across the plurality of virtual servers.

10. The method of claim 1, comprising executing, by one of the appliance or a second appliance, the first virtual server.

11. The method of claim 1, wherein step (d) comprises obtaining, by the appliance, the one of metrics via a metric exchanging protocol or Simple Network Management Protocol (SNMP).

12. The method of claim 1, wherein the one or more metrics comprises one of the following:

a number of connections, a number of packets sent to or transmitted by the virtual server, a response time of the service load balanced by a virtual server, and use of network bandwidth by the service.

13. The method of claim 1, comprising identifying, by a user, one or more metrics of one of the first virtual backup server or the virtual server to collection for load balancing.

21. The system of claim -1-918, wherein the monitoring agent further continues to transmit requests directed to the first virtual server to the one of the first backup virtual server or the first virtual server.

15. A system for performing load balancing via a plurality of virtual servers upon a failover using metrics from a backup virtual server, the system comprising:

an appliance load balancing a plurality of virtual servers, a first virtual server of the plurality of virtual servers having one or more backup virtual servers;

a monitoring agent of the appliance detecting that the first virtual server is not available, identifying that a first backup virtual server of the one or more backup virtual servers is available and maintaining the status of the first virtual server as available in response to identification;

a load monitor of the appliance obtaining one or more metrics from the first backup virtual server of the plurality of the one or more backup virtual servers and determining the load across the plurality of virtual servers using the metrics obtained from the first backup virtual server for determining the load of the first virtual server.

14. The method of claim 19, comprising identifying, by the user, one of a weight or a threshold to assign to each of the user selected metrics.

16. The system of claim 15, wherein the monitoring agent further identifies that the first virtual backup server is unavailable and the load monitor obtains metrics from the second backup virtual server.

17. The system of claim 16, wherein the load monitor further determines the load across the second backup virtual server and the plurality of virtual servers using the metrics obtained from the second backup virtual server.

18. The system of claim 16, wherein the load monitor further determines one of the load across the second backup virtual server or the load across the plurality of virtual servers using the metrics obtained from the second backup virtual server.

19. The system of claim 15, wherein the monitoring agent further identifies that the first virtual server is available.

20. The system of claim 4-918, wherein the load monitor further determines the load across the plurality of virtual servers using the metrics obtained from the first backup virtual server.

22. The system of claim 15, wherein the load monitor determines the load across the plurality of virtual servers using metrics from one or more of a plurality of backup virtual servers.

23. The system of claim 15, wherein a global load balancing virtual server of the appliance determines the load across the plurality of virtual servers.

24. The system of claim 15, wherein one of the appliance or a second appliance executes the first virtual server.

25. The system of claim 16, wherein the load monitor obtains the one of metrics via a metric exchanging protocol or Simple Network Management Protocol (SNMP).

26. The system of claim 16, wherein the one or more metrics comprises one of the following:

a number of connections, a number of packets sent to or transmitted by the virtual server, a response time of the service load balanced by a virtual server, and use of network bandwidth by the service.

27. An appliance for performing load balancing via a plurality of virtual servers upon a failover using metrics from a backup virtual server, the appliance comprising:

means for detecting, by an appliance, that a first virtual server of a plurality of virtual servers load balanced is not available, the first virtual server having one or more backup virtual servers;

means for identifying that a first backup virtual server of a one or more backup virtual servers of the first virtual server is available;

means for maintaining a status of the first virtual server as available in response to the identification;

means for obtaining one or more metrics from the first backup virtual server of a one or more backup virtual servers; and

means for determining the load across the plurality of virtual servers using the metrics obtained from the first backup virtual server associated with the first