SYSTEM AND METHOD FOR COMPLETENESS OF TCP DATA IN TCP HA

• US 20080163248A1
• Filed: 10/15/2007
• Published: 07/03/2008
• Est. Priority Date: 12/29/2006
• Status: Active Grant

• Current Assignee: Futurewei Technologies Incorporated (Huawei Investment & Holding Co., Ltd.)
• Original Assignee: Futurewei Technologies Incorporated (Huawei Investment & Holding Co., Ltd.)
• Inventors: Chen, Huaimo
• Granted Patent: US 8,051,326 B2
• Time in Patent Office: Days
• US Class Current: 719/313
• CPC Class Codes: H04L 69/12 Protocol engines
• CPC Class Codes: H04L 69/16 Implementation or adaptation of Internet protocol [IP], of transmission control protocol [TCP] or of user datagram protocol [UDP]

Abstract

System and method for completeness of transmission control protocol (TCP) high availability (HA) are disclosed. The system includes an active processor, having an application and a TCP, and a standby processor, having another application and another TCP; wherein communications among the active application, the active TCP, the standby application and the standby TCP quickly and efficiently enable the system seamlessly switching over from the active processor to the standby processor for transmission of incoming TCP data streams and outgoing TCP data streams if the active processor fails.

Claims

1. A transmission control protocol (TCP) high availability (HA) system, comprising:

an active processor, having an active application and an active TCP; and

a standby processor, having a standby application and a standby TCP;

wherein communications and data exchanges among the active application, the active TCP, the standby application and the standby TCP provide a mechanism for a seamless switch over of an incoming data stream or an outgoing data stream from the active processor to the standby processor.

2. The system in claim 1, the communications and data exchanges among the active application, the active TCP, the standby application and the standby TCP further comprises synchronizing data structures and state changes between the active application and the standby application.

3. The system in claim 2, further comprises a plurality of sockets, each of the plurality of sockets is associated with an incoming data stream or an outgoing data stream, wherein a notification for the plurality of sockets is sent from the active application to the active TCP.

4. The system in claim 1, wherein the mechanism for the seamless switch over of the incoming data stream from the active processor to the standby processor is provided by a method comprising the steps of:

duplicating a socket associated with the incoming TCP data stream from the active application in the active processor to the standby application in the standby processor;

synchronizing a set of data and a set of states corresponding to the socket associated with the incoming TCP data stream between the active TCP and the standby TCP;

sending a notification, from the active application, to the active TCP that the standby application in the standby processor is ready to receive data from the socket associated with the incoming TCP data stream;

copying a first TCP data received from the socket associated with the incoming TCP data stream, in an input buffer of the active application in the active processor, to the standby application in the standby processor;

sending a sequence number, by the active TCP in the active processor, to the standby TCP in the standby processor, wherein the sequence number corresponds a last byte of the first TCP data delivered through the socket associated the incoming data stream to the active application right before the active TCP receives the notification; and

sending a second TCP data through the socket associated with the incoming TCP data stream, from the standby TCP, to the standby application, wherein the second TCP data starts from a next byte to the last byte of the first TCP data;

thereby the first TCP data, the second TCP data, and subsequent TCP data from a peer router, form a continuous incoming data stream to the standby application in the standby processor for the socket duplicated from the active processor.

5. The method of claim 4, wherein a beginning of the input buffer of the active application to be copied is a boundary of a message.

6. The method of claim 5, wherein the beginning of the input buffer is determined by a point following another complete message decoded in the input buffer.

7. The system of claim 4, wherein the standby TCP starts to synchronize an incoming TCP data with the active TCP from a sequence number corresponding to a next byte to the last byte of the first TCP data.

8. The system of claim 4, wherein the sequence number is not a boundary of a message.

9. The system of claim 4, wherein the sequence number is a boundary of a message.

10. The method of claim 4, wherein the notification is sent after the data and states for the socket associated with the incoming TCP data stream are synchronized between the active TCP and the standby TCP, and the data and states are synchronized between the active application and the standby application.

11. The method of claim 4, wherein the notification is sent through an option of the socket associated with the incoming TCP data stream.

12. The method of claim 4, wherein the notification to the active TCP from the active application is through a message for the socket associated with the incoming data stream in the active application.

13. The system in claim 1, wherein the mechanism for the seamless switch over of the outgoing data stream from the active processor to the standby processor is provided using a method comprising the steps of:

duplicating a socket associated with the outgoing data stream from the active application in the active processor to the standby application in the standby processor;

synchronizing data and states related to the socket associated with the outgoing data stream between the active TCP and the standby TCP;

sending a notification, by the active application, to the active TCP that the standby application in the standby processor is ready to snoop outgoing data through the socket associated with the outgoing TCP data stream;

sending a sequence number, by the active TCP in the active processor, to the standby TCP in the standby processor, wherein the sequence number corresponds a last byte of a first TCP data written to the active TCP by the active application right before the active TCP receives the notification;

writing a second TCP data comprising of at least one whole message, from the active application, to the active TCP;

storing the second TCP data into an input buffer by the active TCP;

sending the second TCP data and corresponding boundary information, from the input buffer of the active TCP, to the standby TCP; and

sending the second TCP data, from the standby TCP, to the standby application, wherein the second TCP data starts from a next byte to the last byte of the first TCP data;

thereby the second TCP data and subsequent TCP data written to the active TCP by the active application form a continuous outgoing TCP data stream.

14. The method of claim 13, wherein the sequence number is a boundary of a message.

15. The method of claim 13, wherein the standby TCP starts to synchronize the outgoing data stream with the active TCP from sequence number corresponding to a next byte to the last byte of the first TCP data.

16. The method of claim 13, wherein the notification is sent after the data and states for the socket associated with the outgoing data stream are synchronized between the active TCP and the standby TCP and the data and states are synchronized between the active application and the standby application.

17. The method of claim 13, wherein the notification is sent through an option of the socket associated with the outgoing data stream.

18. The method of claim 13, wherein the notification to the active TCP is through a message for the socket associated with the outgoing data stream.

19. The method of claim 13, further comprises, after the switch-over, data in a buffer of the standby TCP and data from the standby application form a continuous outgoing TCP data stream, and the continuous outgoing TCP data stream is sent to a peer router from the standby processor.

20. A method for providing a transmission of an incoming data stream in a transmission control protocol (TCP) high availability (HA) system, wherein the TCP HA system comprises an active processor, having an active application and an active TCP;

and a standby processor, having a standby application and a standby TCP; and

wherein the active processor and the standby processor are adapted to perform for a seamless switch-over of the incoming data stream from the active processor to the standby processor, comprising the steps of;

duplicating a socket associated with the incoming data stream, from the active application in the active processor to the standby application in the standby processor;

synchronizing data and states related to socket associated with the incoming data stream between the active TCP and the standby TCP;

sending a notification, by the active application, to the active TCP that the standby application in the standby processor is ready to receive data from the socket associated with the incoming data stream;

copying a first TCP data received from the socket associated with the incoming data stream, in an input buffer of the active application in the active processor, to the standby application in the standby processor;

sending a sequence number, by the active TCP in the active processor, to the standby TCP in the standby processor, wherein the sequence number corresponds a last byte of the first TCP data delivered through the socket associated with the incoming data stream, to the active application right before the active TCP receives the notification; and

sending a second TCP data through the socket associated with the incoming data stream, from the standby TCP, to the standby application, wherein the second TCP data starts from a next byte to the last byte of the first TCP data;

thereby the first TCP data, the second TCP data, and subsequent incoming TCP data from a peer router, form a continuous incoming data stream to the standby application in the standby processor for the socket duplicated from the active processor.

21. The method of claim 20, wherein a beginning of the input buffer is a boundary of a message.

22. The method of claim 21, wherein the beginning of the input buffer is determined by a point following another complete message decoded in the input buffer.

23. The method of claim 20, wherein the sequence number is not a boundary of a message.

24. The method of claim 20, wherein the sequence number is a boundary of a message.

25. A method for providing a transmission of an outgoing data stream in a transmission control protocol (TCP) high availability (HA) system, wherein the TCP HA system comprises an active processor, having an active application and an active TCP;

and a standby processor, having a standby application and a standby TCP; and

wherein the active processor and the standby processor are adapted to perform for a seamless switch-over of the outgoing data stream from the active processor to the standby processor, comprising the steps of;

duplicating a socket associated with the outgoing data stream from the active application in the active processor to the standby application in the standby processor;

synchronizing data and states related to the socket associated with the outgoing data stream between the active TCP and the standby TCP;

sending a notification, by the active application, to the active TCP that the standby application in the standby processor is ready to snoop outgoing data through the socket associated with the outgoing data stream;

sending a sequence number, by the active TCP in the active processor, to the standby TCP in the standby processor, wherein the sequence number corresponds a last byte of a first TCP data written to the active TCP by the active application right before the active TCP receives the notification;

writing a second TCP data comprising at least one whole message, from the active application, to the active TCP;

storing the second TCP data into an input buffer by the active TCP;

sending the second TCP data and corresponding boundary information, from the input buffer of the active TCP, to the standby TCP; and

sending the second TCP data, from the standby TCP, to the standby application, wherein the second TCP data starts from a next byte to the last byte of the first TCP data;

thereby the second TCP data and subsequent TCP data written to the active TCP by the active application, is a continuous outgoing TCP data stream.

26. The method of claim 25, wherein a beginning of the input buffer is a boundary of a message.

27. The method of claim 26, wherein the beginning of the input buffer is determined by a point following another complete message decoded in the input buffer.

28. The method of claim 25, wherein the sequence number is a boundary of a message.