Message redirector with cut-through switch for highly reliable and efficient network traffic processor deployment

• US 6,327,242 B1
• Filed: 03/17/1998
• Issued: 12/04/2001
• Est. Priority Date: 03/17/1998
• Status: Expired due to Term

• Current Assignee: F5 Networks, Inc. (F5 Incorporated)
• Original Assignee: InfoLibria, Inc. (Hitachi, Ltd.)
• Inventors: Chow, Ray Y., Amicangioli, Anthony D., Yates, David J.
• Primary Examiner(s): Chin, Wellington
• Assistant Examiner(s): Pham, Brenda H.
• Application Number:
  US09/040,519
• Time in Patent Office: 1,358 Days
• Field of Search: 370/389, 370/392, 370/395, 370/396, 370/401, 370/397, 370/398, 370/399, 370/464, 370/466, 370/470, 370/471, 370/474, 370/216, 370/221, 370/225
• US Class Current: 370/216
• CPC Class Codes: H04L 67/563 Data redirection of data network streams
• CPC Class Codes: H04L 67/568 Storing data temporarily at an intermediate stage, e.g. caching
• CPC Class Codes: H04L 69/40 for recovering from a failure of a protocol instance or entity, e.g. service redundancy protocols, protocol state redundancy or protocol service redirection management of faults, events, alarms or notifications in data switching networks H04L41/06

Abstract

A redirector device for enabling highly reliable deployment of in line network traffic server (such as a document cache) or processor (such as a network monitoring and management device). In normal operation, the device selectively redirects traffic at a link layer to the traffic server, by type of message received or client address or application, server address or application, adjacent network node address, or other parameters. However, the device also detects failures of the traffic server, and when appropriate, switches line traffic to bypass the server. This implements a fail safety feature for the server in the sense that a failure causes traffic to be forwarded past the server, thereby enabling the network to remain operational.

Claims

1. An apparatus for receiving messages from a network comprising:

(a) a traffic processor, for processing messages in a manner which is transparent to other devices connected to the network;

(b) a message redirector, comprising a cut through switch which is selectively activated upon failure of the traffic processor; and

(c) a controller, connected between the traffic processor and the message redirector, to control the state of the cut through switch,

wherein the message redirector connects to a plurality of cache servers in a failsafe topology and when a predetermined number of cache servers fail, directs the controller to activate the cut through switch.

2. An apparatus as in claim 1 wherein the traffic processor processes messages at a link layer in a protocol stack.

3. An apparatus as in claim 1 additionally comprising:

(d) a watchdog timer, disposed in the message redirector, and connected to control the cut through switch.

4. An apparatus as in claim 1 additionally comprising:

(d) a watchdog timer, disposed in the traffic processor, and connected to control the cut through switch.

5. An apparatus as in claim 1 wherein the cut through switch is selectively activated based upon a type of message received.

6. An apparatus as in claim 1 wherein the cut through switch is selectively activated based upon an address in a message received.

7. An apparatus as in claim 6 wherein the address is an Internet protocol layer address.

8. An apparatus as in claim 1 wherein multiple message redirectors are connected to a given traffic server.

9. An apparatus as in claim 1 wherein multiple traffic servers are connected to a given message redirector.

10. An apparatus as in claim 9 wherein the message redirector implements load balancing among the multiple traffic servers.

11. A method for use in a computer network for processing messages received by a network traffic server comprising a traffic processor, said network traffic server implementing a layered communication protocol, the method comprising the steps of:

(a) processing messages by receiving requests from clients in a network and responding thereto; and

(b) redirecting client request messages by selectively activating a cut through switch to bypass the network traffic server altogether upon failure of the step of responding to the client requests, characterized in that the traffic processor uses a link layer of said communication protocol for redirecting client requests without modifying high level protocol layers of other devices connected to the network, this processing being thereby transparent to the other devices connected to the network.

12. A method as in claim 11 wherein the step of processing messages comprises the step of retrieving documents from a local cache server.

13. A method as in claim 11 wherein the step of processing message traffic further comprises the step of:

(c) controlling the step of redirecting messages with a watchdog timer.

14. A method as in claim 11 wherein the step of redirecting messages further comprises:

(c) controlling the redirection of messages with a watchdog timer.

15. A method as in claim 11 wherein the step of redirecting messages is selectively performed based upon the type of message received.

16. A method as in claim 11 wherein the step of redirecting messages is selectively performed based upon an address in the message received.

17. A method as in claim 16 wherein the address is an Internet protocol layer address.

18. A method as in claim 11 wherein the step of redirecting messages is performed upon messages received in line from the network.

19. A method as in claim 11 wherein the step of redirecting messages is carried out with a four port device having two ports connected to external network ports and two ports connected to a message traffic processor which carries out the message processing step.

20. A method as in claim 11 wherein the step of redirecting client request messages further comprises the step of:

(c) selectively redirecting messages between two external network ports or between two ports connected to carry out the message processing step.

21. A method as in claim 11 wherein the step of redirecting client request messages additionally comprising the step of:

(d) routing a message among multiple message redirectors to carry out the message processing step.

22. A method as in claim 11 additionally comprising the step of:

(e) load balancing among multiple traffic processors.

23. A method for processing messages received from a network comprising the steps of:

(a) processing message traffic in a manner which is transparent to other devices connected to the network;

(b) redirecting messages by selectively activating a cut through switch upon failure of the message traffic processing step; and

(c) load balancing among multiple traffic processors,

wherein the step of processing message traffic handles messages at a link layer protocol, and such step of processing messages is carried out by the multiple traffic processors; and

wherein the step of redirecting messages is carried out by a single message redirector.