Internet client-server multiplexer

• US 20020147822A1
• Filed: 06/07/2002
• Published: 10/10/2002
• Est. Priority Date: 11/10/1998
• Status: Active Grant

• Current Assignee: Citrix Systems, Inc. (Cloud Software Group)
• Original Assignee: NetScaler Inc. (Cloud Software Group)
• Inventors: Susai, Michel K., Sinha, Rajiv, Setia, Deepinder S., Soni, Ajay V.
• Granted Patent: US 6,954,780 B2
• Time in Patent Office: Days
• US Class Current: 709/229
• 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 67/1008 based on parameters of servers, e.g. available memory or workload monitoring of computer activity G06F11/30
• CPC Class Codes: H04L 67/56 Provisioning of proxy services store-and-forward switching systems in data switching networks H04L12/54
• CPC Class Codes: H04L 67/565 Conversion or adaptation of application format or content adding application control or application functional data H04L67/561
• CPC Class Codes: H04L 69/14 Multichannel or multilink protocols
• CPC Class Codes: H04L 69/16 Implementation or adaptation of Internet protocol [IP], of transmission control protocol [TCP] or of user datagram protocol [UDP]
• CPC Class Codes: H04L 69/163 In-band adaptation of TCP data exchange; In-band control procedures

Abstract

An apparatus, method and computer program product for network client-server multiplexing. The apparatus is implemented within an interface unit connecting a plurality of servers to the Internet, which is connected to a plurality of clients. According to a “connection pooling” aspect of the invention, the interface unit opens and maintains connections with the servers and handles the opening and closing of connections with clients accessing the servers, thereby freeing the servers of the processing load incurred by opening and closing connections. According to a “connection distribution” aspect of the invention, the interface unit examines the path names within requests received from clients and selects the server hosting the requested information according to the path names.

Claims

1. An apparatus comprising:

means for opening a connection between a client and an interface unit;

means for opening a connection between said interface unit and a server if no free connection is open between said interface unit and said server;

means for allowing said client to access information on said server via said connections; and

means for closing said connection between said client and said interface unit while keeping open said connection between said interface unit and said server.

2. The apparatus of claim 1, further comprising:

means for opening a connection between a further client and said interface unit; and

means for allowing said further client to access information on said server via said connection between said further client and said interface unit and said connection between said interface unit and said server.

3. The apparatus of claim 1, wherein said means for opening said connection between said client and said interface unit comprises:

means for receiving a request to open a connection using a network address corresponding to said interface unit; and

means for receiving a request to retrieve data using a path name corresponding to said server.

4. The apparatus of claim 3, wherein said means for opening said connection between said further client and said interface unit comprises:

means for selecting said server as a function of said network address.

5. The apparatus of claim 4, wherein said means for allowing comprises:

means for retrieving said data from said server using said path name.

6. The apparatus of claim 5, wherein said means for allowing further comprises:

means for sending said data to said client.

7. The apparatus of claim 5, wherein:

said means for receiving a request to retrieve data comprises means for receiving a GET segment having sequence and acknowledgment parameters; and

said means for retrieving comprises

means for modifying said parameters to produce a modified GET segment, and

means for sending said modified GET segment to said server.

8. The apparatus of claim 7, wherein said means retrieving further comprises:

means for inserting a “

Connection;

Keep-Alive”

header into said modified GET segment;

means for subtracting from said acknowledge parameter received from said server the number of bytes added by inserting said “

Connection;

Keep-Alive”

header into said modified GET segment; and

means for adding to said sequence number prior to sending a packet subsequent to said modified GET segment to said server the number of bytes added by inserting said “

Connection;

Keep Alive”

header into said modified GET segment.

9. The apparatus of claim 7, wherein said means for retrieving further comprises:

means for receiving a RESP segment having further sequence and acknowledgment parameters;

means for modifying said further parameters to produce a modified RESP segment; and

means for sending said modified RESP segment to said client.

10. The apparatus of claim 5, wherein:

said means for receiving a request to retrieve data comprises means for receiving a first GET segment having sequence and acknowledgment parameters; and

said means for retrieving comprises

means for modifying said parameters to produce modified parameters, and

means for sending a second GET segment to said server, said second GET segment having said modified parameters.

11. The apparatus of claim 7, wherein said means for retrieving further comprises:

means for receiving a first RESP segment having further sequence and acknowledgment parameters;

means for modifying said further parameters to produce further modified parameters; and

means for sending a second RESP segment to said client, said second RESP segment having said further modified parameters.

13. The apparatus of claim 12, wherein said means for receiving comprises:

means for receiving from said client a request to open a connection to a host using said network address; and

means for receiving from said client a request to retrieve data using said path name.

14. The apparatus of claim 12, further comprising:

means for receiving a further request to retrieve further data using said network address and a further path name;

means for selecting a further server as a function of said further path name; and

means for retrieving said further data from said further server.

15. The apparatus of claim 12, wherein:

said means for receiving a request to retrieve data comprises means for receiving a first GET segment having sequence and acknowledgment parameters; and

said means for retrieving comprises

means for modifying said parameters to produce a modified GET segment, and

means for sending said modified GET segment to said server.

16. The apparatus of claim 15, wherein said means retrieving further comprises:

means for inserting a “

Connection;

Keep-Alive”

header into said modified GET segment;

means for subtracting from said acknowledge parameter received from said server the number of bytes added by inserting said “

Connection;

Keep-Alive”

header into said modified GET segment; and

means for adding to said sequence number prior to sending a packet subsequent to said modified GET segment to said server the number of bytes added by inserting said “

Connection;

Keep Alive”

header into said modified GET segment.

17. The apparatus of claim 15, wherein said means for retrieving further comprises:

means for receiving a first RESP segment having further sequence and acknowledgment parameters;

means for modifying said further parameters to produce a modified RESP segment; and

means for sending said modified RESP segment to said client.

18. The apparatus of claim 12, wherein:

said means for receiving a request to retrieve data comprises means for receiving a first GET segment having sequence and acknowledgment parameters; and

said means for retrieving comprises

means for modifying said parameters to produce modified parameters, and

means for sending a second GET segment to said server, said second GET segment having said modified parameters.

19. The apparatus of claim 15, wherein said means for retrieving further comprises:

means for receiving a first RESP segment having further sequence and acknowledgment parameters;

means for modifying said further parameters to produce further modified parameters; and

means for sending a second RESP segment to said client, said second RESP segment having said further modified parameters.

12. An apparatus comprising:

means for receiving from a client a request to retrieve data using a network address and a path name;

means for selecting a server storing said data as a function of predefined policies including at least one of said path name, the load of said server, and the state of said server;

means for retrieving said data from said server using a previously-opened connection; and

means for sending said data to said client.

20. A method comprising the steps of:

opening a connection between a client and an interface unit;

opening a connection between said interface unit and a server if no free connection is open between said interface unit and said server;

allowing said client to access information on said server via said connections; and

closing said connection between said client and said interface unit while keeping open said connection between said interface unit and said server.

21. The method of claim 20, further comprising the steps of:

opening a connection between a further client and said interface unit; and

allowing said further client to access information on said server via said connection between said further client and said interface unit and said connection between said interface unit and said server.

22. The method of claim 20, wherein said step of opening said connection between said client and said interface unit comprises the steps of:

receiving a request to open a connection using a network address corresponding to said interface unit; and

receiving a request to retrieve data using a path name corresponding to said server.

23. The method of claim 22, wherein said step of opening said connection between said further client and said interface unit comprises the step of:

selecting said server as a function of said network address.

24. The method of claim 23, wherein said allowing step comprises the step of:

retrieving said data from said server using said path name.

25. The method of claim 24, wherein said allowing step further comprises the step of:

sending said data to said client.

26. The method of claim 24, wherein:

said step of receiving a request to retrieve data comprises the step of receiving a GET segment having sequence and acknowledgment parameters; and

said retrieving step comprises the steps of

modifying said parameters to produce a modified GET segment, and

sending said modified GET segment to said server.

27. The apparatus of claim 26, wherein said means retrieving further comprises:

inserting a “

Connection;

Keep-Alive”

header into said modified GET segment;

subtracting from said acknowledge parameter received from said server the number of bytes added by inserting said “

Connection;

Keep-Alive”

header into said modified GET segment; and

adding to said sequence number prior to sending a packet subsequent to said modified GET segment to said server the number of bytes added by inserting said “

Connection;

Keep Alive”

header into said modified GET segment.

28. The method of claim 26, wherein said retrieving step further comprises the steps of:

receiving a RESP segment having further sequence and acknowledgment parameters;

modifying said further parameters to produce a modified RESP segment; and

sending said modified RESP segment to said client.

29. The method of claim 24, wherein:

said step of receiving a request to retrieve data comprises the step of receiving a first GET segment having sequence and acknowledgment parameters; and

said retrieving step comprises the steps of

modifying said parameters to produce modified parameters, and

sending a second GET segment to said server, said second GET segment having said modified parameters.

30. The method of claim 26, wherein said retrieving step further comprises the steps of:

receiving a first RESP segment having further sequence and acknowledgment parameters;

modifying said further parameters to produce further modified parameters; and

sending a second RESP segment to said client, said second RESP segment having said further modified parameters.

31. A method comprising the steps of:

receiving from a client a request to retrieve data using a network address and a path name;

selecting a server storing said data as a function of predefined policies including at least one of said path name, the load of said server, and the state of said server;

retrieving said data from said server using a previously-opened connection; and

sending said data to said client.

32. The method of claim 31, wherein said receiving step comprises the steps of:

receiving from said client a request to open a connection to a host using said network address; and

receiving from said client a request to retrieve data using said path name.

33. The method of claim 31, further comprising the steps of:

receiving a further request to retrieve further data using said network address and a further path name;

selecting a further server as a function of said further path name; and

retrieving said further data from said further server.

34. The method of claim 31, wherein:

said step of receiving a request to retrieve data comprises the step of receiving a first GET segment having sequence and acknowledgment parameters; and

said retrieving step comprises the steps of

modifying said parameters to produce a modified GET segment, and

sending said modified GET segment to said server.

35. The apparatus of claim 34, wherein said means retrieving further comprises:

inserting a “

Connection;

Keep-Alive”

header into said modified GET segment;

subtracting from said acknowledge parameter received from said server the number of bytes added by inserting said “

Connection;

Keep-Alive”

header into said modified GET segment; and

adding to said sequence number prior to sending a packet subsequent to said modified GET segment to said server the number of bytes added by inserting said “

Connection;

Keep Alive”

header into said modified GET segment.

36. The method of claim 34, wherein said retrieving step further comprises the steps of:

receiving a first RESP segment having further sequence and acknowledgment parameters;

modifying said further parameters to produce a modified RESP segment; and

sending said modified RESP segment to said client.

37. The method of claim 31, wherein:

said step of receiving a request to retrieve data comprises the step of receiving a first GET segment having sequence and acknowledgment parameters; and

said retrieving step comprises the steps of

modifying said parameters to produce modified parameters, and

sending a second GET segment to said server, said second GET segment having said modified parameters.

38. The method of claim 34, wherein said retrieving step further comprises the steps of:

receiving a first RESP segment having further sequence and acknowledgment parameters;

modifying said further parameters to produce further modified parameters; and

sending a second RESP segment to said client, said second RESP segment having said further modified parameters.