Persistent redirection engine

• US 20030126266A1
• Filed: 01/02/2003
• Published: 07/03/2003
• Est. Priority Date: 01/03/2002
• Status: Abandoned Application

• Current Assignee: Radware Limited
• Original Assignee: Radware Limited
• Inventors: Peles, Amir
• Application Number:
  US10/335,715
• Publication Number:
  US 20030126266A1
• Time in Patent Office: Days
• US Class Current: 709/228
• 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 67/1008 based on parameters of servers, e.g. available memory or workload monitoring of computer activity G06F11/30
• CPC Class Codes: H04L 67/1027 Persistence of sessions during load balancing
• CPC Class Codes: H04L 67/1034 Reaction to server failures by a load balancer
• 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

During a web transaction initiation, a switch selects a specific server with which to connect; however, it will not pass the request to the server but, rather, will instruct the client to connect to another IP address corresponding to the specific server. This IP address is an additional address on the switch that will always send the requests to the same server. As long as the server is active and capable of serving users, the user will perform remaining transactions towards this IP address and will remain connected to the same server. Once the server is down, the switch recognizes the situation and all subsequent requests received are responded to with a new address for use. The new address is an address of another server that is active and to which the user may connect.

Claims

1. A method for performing transactions over a network, said method implemented in a switch comprising the steps of:

a. establishing a communication session with a requesting client;

b. receiving cached information from a client, said cached information having at least a virtual network address;

c. associating said virtual network address with a server; and

d. checking if said associated server is faulty, and if so,

i. identifying a non-faulty server and transmitting, to said client, a network address associated with said non-faulty server, whereby said client renegotiates transaction parameters with identified non-faulty server without terminating said communication session;

else

ii. redirecting communications from said client to a non-faulty server corresponding to said virtual network address in said cached information.

2. A method as per claim 1, wherein said network comprises any of:

local area network (LAN), wide area network (WAN), or the Internet.

3. A method as per claim 1, wherein each of said network addresses is an IP address.

4. A method for persistently redirecting communication requests, said method implemented in a switch, said switch having a unique global network address and a plurality of virtual network addresses corresponding to a plurality of servers, said method comprising the steps of:

a. receiving a communication request from a requesting entity; and

b. if said communication request is addressed to said unique global network address, then;

i. identifying a virtual network address associated with a server for said requesting entity to establish a communication; and

ii. transmitting said virtual network address to said requesting entity, whereby said requesting entity addresses communications to said identified virtual network address;

c. else;

i. identifying a virtual network address from said communication request;

ii. identifying a server corresponding to said identified virtual network address; and

iii. redirecting subsequent communications from said requesting entity to said identified server.

5. A method as per claim 4, wherein said method further comprises the steps of:

a. identifying one or more faulty servers in said plurality of servers and identifying corresponding virtual network address associated with said one or more faulty servers; and

b. if said identified virtual network address from said communication request corresponds to a faulty server, including one of the sub-steps of;

i. transmitting to said requesting entity a new virtual address corresponding to a non-faulty server for further communications, and

ii. selecting one of said non-faulty servers and passing, transparent to said requesting entity, said communication request to said selected non-faulty server.

6. A method as per claim 4, wherein said steps of the method are implemented across networks.

7. A method as per claim 6, wherein said across networks element comprises any of:

local area networks (LAN), wide area networks (WAN), or the Internet.

8. A method as per claim 4, wherein each of said network addresses is an IP address.

9. A method as per claim 4, wherein said communication request is any of the following:

a domain name service (DNS) request, a hypertext transfer protocol (HTTP) based request, a real time streaming protocol (RSTP) based request, a session initiation protocol (SIP) based request, or a request of a protocol that supports a resolution or redirection command.

10. A switch interfacing a plurality of servers with one or more clients, said switch comprising:

a. a client interface receiving communications from said one or more clients, said communications addressed either to a global network address associated with said switch or a virtual network address associated with a server in said plurality of servers; and

b. a server interface in communication with said client interface, said server interface facilitating communication with said plurality of servers and identifying faulty and non-faulty servers in said plurality of servers, and

i. if a communication from a client is addressed to a global network address, then instructing said client interface to transmit a virtual network address associated with a non-faulty server to said client;

else

ii. if said communication from said client is addressed to a virtual network address associated with a non-faulty server, then

redirecting communications from said client to said non-faulty sever corresponding to said virtual network address, else at least one of

instructing said client interface to transmit a new virtual network address associated with a non-faulty server to said client, and selecting a non-faulty server and passing, transparent to said client interface, said communication to said selected non-faulty server.

11. A switch interfacing a plurality of servers with one or more clients, as per claim 10, wherein said client interface communicates with said clients over a network.

12. A switch interfacing a plurality of servers with one or more clients, as per claim 11, wherein said network is any of the following:

local area network (LAN), wide area network (WAN), or the Internet.

13. A switch interfacing a plurality of servers with one or more clients, as per claim 10, wherein said network addresses are IP addresses.

14. A switch interfacing a plurality of servers with one or more clients, as per claim 10, wherein said communications are any of the following:

HTTP-based communication, DNS-based communication, RTSP-based communication, SIP-based communication, or a communication based on a protocol that supports a resolution or redirection command.

15. A method for persistently redirecting communication requests, said method implemented in a switch, said switch having a unique global network address and a plurality of virtual network addresses corresponding to a plurality of servers, said method comprising the steps of:

a. receiving a communication request from a requesting entity; and

b. identifying faulty servers and non-faulty servers among said plurality of servers;

c. if said communication request is addressed to said unique global network address, then;

i. identifying a virtual network address associated with a non-faulty server for said requesting entity to establish said communication request; and

ii. transmitting said virtual network address to said requesting entity, whereby said requesting entity addresses further communications to said virtual network address;

d. else;

i. identifying a virtual network address from said communication request;

ii. if said identified virtual address from said communication request corresponds to a non-faulty server, then;

redirecting subsequent communications from said requesting entity to said identified server, else at least one of

identifying and transmitting a new virtual network address associated with a non-faulty server and instructing said requesting entity to renegotiate a communication session using said new virtual network address, and selecting a non-faulty server and passing, transparent to said requesting entity, said subsequent communications to said selected non-faulty server.

16. A method as per claim 15, wherein said steps of the method are implemented across networks, said networks including any combination of local area networks (LAN), wide area networks (WAN), or the Internet.

17. A method as per claim 15, wherein said network address is an IP address.

18. A method as per claim 15, wherein said communications are any of the following:

HTTP-based communication, DNS-based communication, RTSP-based RADW 19.128 communication, SIP-based communication, or a communication based on a protocol that supports a resolution or redirection command.

19. A system for persistently redirecting communication requests from clients without utilizing client stored cookies, said system having a unique global network address and a plurality of virtual network addresses corresponding to a plurality of servers, said system comprising:

a client interface unit that connects to at least one client and sending and receiving communications with a client;

a server interface unit for connecting to said plurality of servers and for sending and receiving communications with said plurality of servers;

a processing unit that identifies an address in a received communication request from a client, if said communication request is addressed to said unique global network address, then identifying a virtual network address associated with a server for said requesting client to establish communication with and providing said virtual network address to said client interface unit for transmitting to said requesting client,

wherein said requesting client addresses subsequent communications to said virtual network address and said processing unit receiving subsequent communications redirecting the subsequent communications from said requesting client to a server identified by the virtual network address included in the subsequent communications.

20. The system of claim 19, wherein said processing unit further identifies faulty servers and servers among said plurality of servers and when said communication request corresponds to a faulty server at least one of

identifying and transmitting a new virtual network address associated with a non-faulty server to said client, and

selecting a non-faulty server and passing, transparent to said requesting client, said subsequent communications to said selected non-faulty server.