Systems and Methods for Providing Dynamic Spillover of Virtual Servers Based on Bandwidth

• US 20080049786A1
• Filed: 03/12/2007
• Published: 02/28/2008
• Est. Priority Date: 08/22/2006
• Status: Active Grant

• Current Assignee: Citrix Systems, Inc. (Cloud Software Group)
• Original Assignee: Citrix Systems, Inc. (Cloud Software Group)
• Inventors: Kamath, Sandeep, Verzunov, Sergey, Suganthi, Josephine, Ram, Maruthi
• Granted Patent: US 8,312,120 B2
• Time in Patent Office: Days
• US Class Current: 370/468
• CPC Class Codes: G06F 9/5083 Techniques for rebalancing the load in a distributed system
• 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 67/2871 Implementation details of single intermediate entities
• CPC Class Codes: H04L 67/288 Distributed intermediate devices, i.e. intermediate devices for interaction with other intermediate devices on the same level
• CPC Class Codes: H04L 67/563 Data redirection of data network streams
• CPC Class Codes: H04L 67/59 Providing operational support to end devices by off-loading in the network or by emulation, e.g. when they are unavailable
• CPC Class Codes: H04L 67/63 Routing a service request depending on the request content or context

Abstract

The present solution provides a spillover management technique for virtual servers of an appliance based on bandwidth. A network administrator may configure a bandwidth threshold for one or more virtual servers, such as virtual servers providing acceleration or load balancing for one or more services. The bandwidth threshold may be specified as a number of bytes transferred via the virtual server. The bandwidth threshold may also be specified as a round trip time or derivative thereof. A user may specify the bandwidth threshold via a configuration interface. Otherwise, the appliance may establish the bandwidth threshold. The appliance monitors the bandwidth used by a first virtual server. In response to detecting the bandwidth reaching or exceeding the bandwidth threshold, the appliance dynamically directs client requests to a second virtual server.

Claims

1. A method for an appliance to direct connection requests of a first virtual server managing a first plurality of services to a second virtual server upon exceeding by the first virtual server a bandwidth threshold, the method comprising the steps of:

(a) establishing, via an appliance, a bandwidth threshold for a first virtual server for directing connection requests from a plurality of clients to a first plurality of services;

(b) monitoring, by the appliance, bandwidth used by the first virtual server;

(c) determining, by the appliance, the monitored bandwidth of the first virtual server exceeds the bandwidth threshold; and

(d) directing, by the appliance in response to the determination, a connection request of a client to a second virtual server.

2. The method of claim 1, comprising identifying, via the appliance, the second virtual server as a backup virtual server for the first virtual server.

3. The method of claim 1, comprising establishing, by the appliance in response to the determination, the second virtual server.

4. The method of claim 1, wherein step (b) comprises determining, by the appliance, a number of bytes per second transferred from the appliance to the first plurality of services.

5. The method of claim 1, wherein step (b) comprises determining, by the appliance, a number of bytes per second transferred from the appliance to the plurality of clients.

6. The method of claim 1, wherein step (b) comprises determining, by the appliance, a number of bytes per second received by the appliance.

7. The method of claim 1, wherein step (b) comprises determining, by the appliance, a number of bytes per second transmitted by the appliance.

8. The method of claim 1, comprising transmitting, by the second virtual server, the connection request to a service of the plurality of services.

9. The method of claim 1, comprising determining, by the appliance via monitoring, the bandwidth used by the first virtual server falls below the bandwidth threshold.

10. The method of claim 9, comprising directing, by the appliance in response to the determination, connection requests to the first virtual server instead of the second virtual server.

11. The method of claim 9, comprising receiving, by the appliance a request from the client via a connection established via the second virtual server, and providing the request to the second virtual server.

12. The method of claim 1, comprising receiving, by the appliance a request from a client via a connection established with the first virtual server, and providing the request to the first virtual server.

13. The method of claim 1, wherein step (b) comprises monitoring, by the appliance, the bandwidth used by the first virtual server at a predetermined frequency.

14. The method of claim 1, comprising determining, by the appliance, bandwidth used by the second virtual server exceeds a second bandwidth threshold, and directing client requests to a third virtual server instead of the second virtual server.

15. The method of claim 1, wherein step (d) comprises identifying, by the appliance, bandwidth used by the second virtual server is within a second bandwidth threshold.

16. The method of claim 1, comprising adjusting, by the appliance, the bandwidth threshold based on one of a performance or operational characteristics of the first virtual server.

17. The method of claim 1, comprising monitoring, by the appliance, a number of connections of the first virtual server.

18. The method of claim 17, comprising determining, by the appliance, to direct a connection request of the client to the second virtual server based on the number of connections of the first virtual server and the bandwidth used by the first virtual server.

19. The method of claim 1, comprising determining, by the appliance, bandwidth used by the first virtual server exceeds the bandwidth threshold, and redirecting the request of the client to one of a second appliance, a server or a service.

20. The method of claim 19, wherein the appliance uses a redirect uniform resource locator configured for the first virtual server to redirect the request of the client.

21. The method of claim 1, comprising determining, by the appliance, bandwidth used by the first virtual server exceeds the bandwidth threshold, and providing the client with a redirect uniform resource locator to one of a second appliance, a server or a service.

22. The method of claim 1, wherein the bandwidth threshold comprises a predetermined number of bytes per second.

23. An appliance directing connection requests from a first virtual server managing a first plurality of services to a second virtual server upon exceeding by the first virtual server a bandwidth threshold, the appliance comprising:

a virtual server switching mechanism determining to direct requests from clients to a virtual server of a plurality of virtual servers;

a first virtual server for directing connection requests from a plurality of clients to a first plurality of services;

a load monitor establishing a bandwidth threshold for the first virtual server, the load monitor monitoring the bandwidth used by the first virtual server;

wherein the load monitor determines the bandwidth used by the first virtual server exceeds the bandwidth threshold, and in response to the determination, the virtual server switching mechanism directs a connection request of a client to a second virtual server.

24. The appliance of claim 23, comprising a configuration interface receiving information from a user identifying the second virtual server as a backup virtual server for the first virtual server.

25. The appliance of claim 23, wherein the appliance establishes the second virtual server in response to the determination the bandwidth used by the first virtual server exceeds the bandwidth threshold.

26. The appliance of claim 23, wherein the load monitor determines a number of bytes per second transferred from the first virtual server to the first plurality of services.

27. The appliance of claim 23, wherein the load monitor determines a number of bytes per second transferred from the first virtual server to the plurality of clients.

28. The appliance of claim 23, wherein the load monitor determines a number of bytes per second received by the first virtual server.

29. The appliance of claim 23, wherein the load monitor determines a number of bytes per second transmitted by the first virtual server.

30. The appliance of claim 23, comprising a configuration information receiving information from a user identifying the bandwidth threshold as one of a predetermined number of kilobytes or a predetermined number of megabytes.

31. The appliance of claim 23, wherein the second virtual server transmits the connection request to a service of the plurality of services.

32. The appliance of claim 31, wherein the load monitor determines bandwidth used by the first virtual server falls below the bandwidth threshold.

33. The appliance of claim 32, wherein the virtual server switching mechanism, in response to the determination, directs connection requests to the first virtual server instead of the second virtual server.

34. The appliance of claim 32, wherein the virtual server switching mechanism receives a request from a client via a connection established via the second virtual server, and provides the request to the second virtual server.

35. The appliance of claim 23, wherein the virtual server switching mechanism receives a request from a client via a connection established via the first virtual server, and provides the request to the first virtual server.

36. The appliance of claim 23, wherein the load monitor monitors the bandwidth used the first virtual server at a predetermined frequency.

37. The appliance of claim 23, wherein the load monitor determines bandwidth used by the second virtual server exceeds a second bandwidth threshold, and in response to the load monitor, the virtual server switching mechanism directs client requests to a third virtual server instead of the second virtual server.

38. The appliance of claim 37, wherein the load monitor determines bandwidth used by the second virtual server is within a second bandwidth threshold.

39. The appliance of claim 23, wherein the appliance adjusts the bandwidth threshold based on one of a performance or operational characteristics of the first virtual server.

40. The appliance of claim 23, wherein the load monitor monitors a number of connections of the first virtual server.

41. The appliance of claim 40, wherein the virtual server switching mechanism determines to direct a connection request of the client to the second virtual server based on the number of connections of the first virtual server and the bandwidth used by the first virtual server.

42. The appliance of claim 23, wherein the load monitor determines bandwidth used by the first virtual server exceeds the bandwidth threshold, and in response to the determination, the virtual server switching mechanism redirects the request of the client to one of a second appliance, a server or a service.

43. The appliance of claim 42, wherein the appliance uses a redirect uniform resource locator configured for the first virtual server to redirect the request of the client.

44. The appliance of claim 23, wherein the load monitor determines, bandwidth used by the first virtual server exceeds the bandwidth threshold, and in response to the determination, the virtual server switching mechanism provides the client with a redirect uniform resource locator to one of a second appliance, a server or a service.

45. The appliance of claim 23, wherein the bandwidth threshold comprises a predetermined number of bytes per second.

46. A method for performing bandwidth management of a virtual server on an object basis, the method comprising the steps of:

(a) establishing, on an appliance, a first virtual server for directing requests to a second virtual server based on requests corresponding to an object type;

(b) establishing, via the appliance, a bandwidth threshold for the second virtual server;

(c) directing, by the first virtual server, to the second virtual server client requests corresponding to the object type; and

(d) monitoring, by the appliance, bandwidth used by the second virtual server to determine if the bandwidth exceeds the bandwidth threshold.

47. The method of claim 46, comprising determining, by the appliance, the monitored bandwidth of the second virtual server exceeds the bandwidth threshold.

48. The method of claim 47, comprising directing, by the appliance in response to the determination, a request of the client to a third virtual server.

49. The method of claim 48, comprising handling, by the third virtual server, requests corresponding to the object type.

50. The method of claim 46, comprising determining, by the first virtual server, a request of a client corresponds to the object type by comparing the request to a pattern for at least a portion of a uniform resource locator.

51. The method of claim 46, comprising determining, by the first virtual server, a request of a client has a predetermined file extension corresponding to the object type.

52. The method of claim 46, comprising determining, by the first virtual server, a request of a client corresponds to the object type responsive to a policy of a policy engine.

53. The method of claim 46, comprising determining, by the first virtual server, a request of a client corresponds to the object type by applying a content switching policy to content of the request.

54. The method of claim 46, wherein step (d) comprises determining, by the appliance, a number of bytes per second transferred between the second virtual server and a plurality of services.

55. The method of claim 46, wherein step (d) comprises determining, by the appliance, a number of bytes per second transferred between the second virtual server and a plurality of clients.

56. The method of claim 46, wherein step (d) comprises determining, by the appliance, a number of bytes one of received or transmitted by the second virtual server for a predetermined time period.

57. The method of claim 46, comprising transmitting, by the second virtual server, requests to a plurality of services.

58. The method of claim 46, comprising determining, by the appliance via monitoring, the bandwidth used by the second virtual server falls below the bandwidth threshold.

59. The method of claim 58, comprising redirecting, by the first virtual server in response to the determination, requests to the second virtual server instead of a third virtual server.

60. The method of claim 59, comprising receiving, by the first virtual server a request from a client via a connection established via the third virtual server, and providing the request to the third virtual server.

61. The method of claim 47, comprising receiving, by the first virtual server, a request from a client via a connection established via the second virtual server, and providing the request to the second virtual server.

62. The method of claim 46, comprising determining, by the first virtual server, the bandwidth used by the second virtual server exceeds the bandwidth threshold, and redirecting client requests to one of the following:

a second appliance, a server or a service.

63. The method of claim 46, wherein step (e) comprises identifying, by the appliance, the bandwidth used by the second virtual server is within a second bandwidth threshold.

64. The method of claim 46, comprising determining, by the appliance, bandwidth used by the second virtual server exceeds the bandwidth threshold, and redirecting a request of the client to one of a second appliance, a server or a service.

65. The method of claim 64, wherein the appliance uses a redirect uniform resource locator configured for one of the first virtual server or the second virtual server to redirect the request of the client.

66. The method of claim 46, comprising determining, by the appliance, bandwidth used by the second virtual server exceeds the bandwidth threshold, and providing the client with a redirect uniform resource locator to one of a second appliance, a server or a service.