Packet switch and method thereof dependent on application content

• US 20060031374A1
• Filed: 09/02/2005
• Published: 02/09/2006
• Est. Priority Date: 06/18/2001
• Status: Active Grant

• Current Assignee: International Business Machines Corporation
• Original Assignee: Transtech Networks USA, Inc.
• Inventors: Lu, Leonard L., Cheng, Bo-Chao, Wu, Tsong-Ho, Hsing, Deh-Phone K.
• Granted Patent: US 7,437,473 B2
• Time in Patent Office: Days
• US Class Current: 709/207
• CPC Class Codes: H04L 45/74 Address processing for routing
• CPC Class Codes: H04L 47/10 Flow control; Congestion control
• CPC Class Codes: H04L 47/19 at layers above the network layer network arrangements for networked applications for scheduling or organising the servicing of application requests H04L67/60
• CPC Class Codes: H04L 47/2458 Modification of priorities while in transit
• CPC Class Codes: H04L 47/2466 using signalling traffic
• CPC Class Codes: H04L 47/25 with rate being modified by the source upon detecting a change of network conditions
• CPC Class Codes: H04L 47/32 by discarding or delaying data units, e.g. packets or frames
• CPC Class Codes: H04L 63/08 for authentication of entities cryptographic mechanisms or cryptographic arrangements for entity authentication H04L9/32
• CPC Class Codes: H04L 63/101 Access control lists [ACL]
• CPC Class Codes: H04L 67/02 based on web technology, e.g. hypertext transfer protocol [HTTP]
• CPC Class Codes: H04L 67/1001 for accessing one among a plurality of replicated servers
• CPC Class Codes: H04L 67/10015 Access to distributed or replicated servers, e.g. using brokers
• CPC Class Codes: H04L 67/1004 Server selection for load balancing
• 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 67/1014 based on the content of a request
• CPC Class Codes: H04L 67/1017 based on a round robin mechanism
• CPC Class Codes: H04L 67/1019 Random or heuristic server selection
• CPC Class Codes: H04L 69/22 Parsing or analysis of headers
• CPC Class Codes: H04L 9/40 Network security protocols

Abstract

A content-aware application switch and methods thereof intelligently switch client packets to one server among a group of servers in a server farm. The switch uses Layer 7 or application content parsed from a packet to help select the server and to schedule the transmitting of the packet to the server. This enables refined load-balancing and Quality-of-Service control tailored to the application being switched. In another aspect of the invention, a slow-start server selection method assigned an initially boosted server load metric to a server newly added to the group of servers under load balancing. This alleviates the problem of the new server being swamped initially due to a very low load metric compared to that of others. In yet another aspect of the invention, a switching method dependent on Layer 7 content avoids delayed binding in a new TCP session. Layer 7 content is not available during the initial handshaking phase of a new TCP session. The method uses the Layer 7 content from a previous session as an estimate to help select the server and uses a default priority to scheduling the transmitting of the handshaking packets. Updated Layer 7 content available after the handshaking phase is then used to reset the priority for the transmit schedule and becomes available for use in load balancing of the next TCP session.

Claims

1-11. -11. (canceled)

12. A method of switching packets to a server among a group of servers, wherein individual packets carry content associated with an application, said method comprising:

receiving a packet;

parsing application content from said packet;

assigning to said packet a priority dependent on said parsed application content; and

dropping the packet if its assigned priority corresponds to a predetermined type.

16. A method of switching packets to a server among a group of servers as in claim 12, wherein said application content includes that from a packet header for Hypertext Transfer Protocol.

13. A method of switching packets to a server among a group of servers, wherein individual packets carry content associated with an application, said method comprising:

receiving a packet;

parsing application content from said packet; and

enforcing security by reference to an access control list dependent on said parsed application content.

14. A method of switching packets to a server among a group of servers, wherein individual packets carry content associated with an application, as in claim 13, wherein said enforcing of security includes dropping the packet if its parsed application content is of a first predetermined type.

15. A method of switching packets to a server among a group of servers, wherein individual packets carry content associated with an application, as in claim 13, wherein said enforcing of security includes redirecting the packet to a predetermined location if its parsed application content is of a second predetermined type.

17-43. -43. (canceled)

44. A switch for switching packets to a server among a group of servers, wherein individual packets carry content associated with an application, said method comprising:

means for receiving a packet;

means for parsing application content from said packet;

means for assigning to said packet a priority dependent on said parsed application content; and

means for dropping the packet if its assigned priority corresponds to a predetermined type.

48. A switch for switching packets to a server among a group of servers as in claim 44, wherein said application content includes that from a packet header for Hypertext Transfer Protocol.

45. A switch for switching packets to a server among a group of servers, wherein individual packets carry content associated with an application, comprising:

means for receiving a packet;

means for parsing application content from said packet; and

means for providing application layer security by enforcing access control dependent on said parsed application content.

46. A switch for switching packets to a server among a group of servers, wherein individual packets carry content associated with an application, as in claim 45, wherein:

said means for providing application layer security includes dropping the packet if its parsed application content is of a first predetermined type.

47. A switch for switching packets to a server among a group of servers, wherein individual packets carry content associated with an application, as in claim 45, wherein:

said means for providing application layer security includes redirecting the packet to a predetermined location if its parsed application content is of a second predetermined type.

49-74. -74. (canceled)