SYSTEMS AND METHODS FOR BYPASSING UNAVAILABLE APPLIANCE

• US 20080034072A1
• Filed: 08/03/2006
• Published: 02/07/2008
• Est. Priority Date: 08/03/2006
• Status: Active Grant

• Current Assignee: Citrix Systems, Inc. (Cloud Software Group)
• Original Assignee: Citrix Systems, Inc. (Cloud Software Group)
• Inventors: Venkatraman, Charu, Shetty, Anil, He, Junxiao, Verzunov, Sergey, Suganthi, Josephine
• Granted Patent: US 8,677,007 B2
• Time in Patent Office: Days
• US Class Current: 709/223
• CPC Class Codes: H04L 41/06 Management of faults, events, alarms or notifications
• CPC Class Codes: H04L 41/5009 Determining service level performance parameters or violations of service level contracts, e.g. violations of agreed response time or mean time between failures [MTBF]
• CPC Class Codes: H04L 43/0811 by checking connectivity
• 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 67/1029 using data related to the state of servers by a load balancer

Abstract

Methods for redirecting, on a client, a communication of the client to a server to upon determining the server is not useable to communicate to the client include the steps of: establishing, by an client agent on a client, a transport layer connection between the client and an intermediary appliance, the intermediary appliance providing access to one or more servers; receiving, by the client agent from the intermediary appliance, address information identifying at least one of the one or more servers available to communicate; determining, by the client agent, the transport layer connection is unusable to communicate; establishing, by the client agent, a second transport layer connection between the client and one of the identified available servers to bypass the appliance. Corresponding systems are also described.

Claims

1. A method for bypassing by a client an appliance gateway used for communicating to a server upon determining the appliance gateway is not useable to communicate to the server, the method comprising the steps of:

(a) establishing, by a client agent, a transport layer connection between a client and an appliance, the appliance providing access to a server;

(b) receiving, by the client agent from the appliance, an application routing table identifying the server or a second appliance;

(c) monitoring, by the client agent, a status of the appliance;

(d) determining, by the client agent via monitoring, the status indicates the appliance is not useable by the client to communicate to the server; and

(e) establishing, by the client agent automatically in response to the determination, a second transport layer connection between the client and the server to bypass the appliance.

2. The method of claim 1, comprises establishing, by the client agent, via the appliance an SSL connection to the server.

3. The method of claim 1, comprising monitoring, by the client agent, the status of one of the second appliance or the server.

4. The method of claim 3, wherein step (e) comprises establishing, by the client agent automatically in response to the determination, a second transport layer connection between the client and the second appliance to bypass the appliance.

5. The method of claim 1, wherein step (a) further comprises establishing, by the client agent, a third transport layer connection between the client and the second appliance.

6. The method of claim 5, comprising determining, by the client agent via monitoring, the status indicates the second appliance is not useable by the client to communicate to the server, and automatically establishing, by the client agent, in response to the determination a fourth transport layer connection between the client and the server.

7. The method of claim 1, comprising performing, by one of the appliance or the client agent, one of the following acceleration techniques on communications transmitted via one of the first transport layer connection or second transport layer connection:

compression;

TCP connection pooling;

TCP connection multiplexing;

TCP buffering; and

caching.

8. The method of claim 1, comprising executing, by the client agent, transparently to one of a network layer, a session layer, or application layer of a network stack of the client.

9. The method of claim 1, comprising executing, by the client, the client agent, transparently to one of an application or a user of the client.

10. The method of claim 1, comprising identifying, by the client agent, the server by intercepting a network communication of the client.

11. A system for bypassing by a client an appliance gateway used for communicating to a server upon determining the appliance gateway is not useable to communicate to the server, the system comprising:

an appliance for providing one or more clients access to a server,

a client agent receiving from the first appliance an application routing table identifying a server or a second appliance, the client agent establishing a transport layer connection between a client and the appliance; and

a monitor of the client agent for monitoring a status of the appliance, the monitor determines the status indicates the appliance is not useable by the client to communicate to the server;

wherein the client agent establishes automatically in response to the determination by the monitor a second transport layer connection between the client and the server to bypass the appliance.

12. The system of claim 11, wherein the client agent establishes via the appliance an SSL connection to the server.

13. The system of claim 11, wherein the monitor monitors the status of one of the second appliance or the server.

14. The system of claim 13, wherein the client agent, automatically in response to the determination by the monitor, establishes a second transport layer connection between the client and the second appliance to bypass the appliance.

15. The system of claim 11, wherein the client agent establishes a third transport layer connection between the client and the second appliance.

16. The system of claim 11, wherein the monitor determines the status indicates the second appliance is not useable by the client to communicate to the server, and the client agent automatically establishes in response to the determination a fourth transport layer connection between the client and the server.

17. The system of claim 11, wherein one of the appliance or the client agent performs one of the following acceleration techniques on communications transmitted via one of the first transport layer connection or second transport layer connection:

compression;

TCP connection pooling;

TCP connection multiplexing;

TCP buffering; and

caching.

18. The system of claim 11, wherein the client agent executes transparently to one of a network layer, a session layer, or application layer of a network stack of the client.

19. The system of claim 11, wherein the client agent executes, transparently to one of an application or a user of the client.

20. The system of claim 11, wherein the client agent identifies the server by intercepting a network communication of the client.