System and method for network load balancing

• US 6,546,423 B1
• Filed: 10/22/1999
• Issued: 04/08/2003
• Est. Priority Date: 10/22/1998
• Status: Expired due to Term

• Current Assignee: Akamai Technologies, Inc.
• Original Assignee: AT&T Corporation (AT&T, Inc.)
• Inventors: Dutta, Partha P., Vidovic, Nino, Vrsalovic, Dalibor F.
• Primary Examiner(s): Burgess, Glenton B.
• Assistant Examiner(s): Le, Hieu C.
• Application Number:
  US09/422,950
• Time in Patent Office: 1,264 Days
• Field of Search: 709/201-203, 709/234-236, 709/224-227, 709/105, 709/217-219, 709/229, 713/151-154, 713/200-201
• US Class Current: 709/225
• 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

Abstract

A system and method for load balancing. A packet is received at a firewall, which implements a rule and refers the packet to a load balancing proxy. The proxy performs a load balancing analysis at the load balancing proxy. Based on the results of the load balancing analysis, the proxy determines a load balancing rule, which is implemented by the firewall. At the end of the session to which the received packet belongs, the load balancing rule is deleted at the firewall.

Claims

1. A method for load balancing, including the steps of:

a. receiving a packet at a firewall;

b. implementing a rule with respect to the packet that refers the packet to a load balancing proxy;

c. performing a load balancing analysis at the load balancing proxy;

d. determining a load balancing rule based upon the load balancing analysis of step c; and

e. implementing the load balancing rule at the firewall.

2. The method of claim 1,wherein the received packet has a source address, source port, destination address, destination port and protocol number.

3. The method of claim 1, further comprising the step of performing a PASS action or a DROP action with respect to a packet received at the firewall.

4. The method of claim 1, further including the steps of determining if a session is terminated, and if the session is terminated, then deleting the load balancing rule at the firewall.

5. An apparatus for load balancing, comprising:

a. a processor;

b. a memory that stores a rule and load balancing instructions adapted to be executed by said processor to receive a packet at a firewall, implementing a rule with respect to the packet that refers the packet to a load balancing proxy, perform a load balancing analysis at the load balancing proxy, determine a load balancing rule based upon the load balancing analysis, and implement the load balancing rule at the firewall, said memory coupled to said processor;

c. a first port adapted to be coupled to the sender of the packet, said first port coupled to said processor; and

d. a second port adapted to be coupled to the destination to which the packet is addressed, said second port coupled to said processor.

6. The apparatus of claim 5, wherein said load balancing instructions are further adapted to be executed by said processor to detect if a session is terminated and to delete a load balancing rule.

7. A medium that stores instructions adapted to be executed by a processor to perform steps including:

a. receiving a packet at a firewall;

b. implementing a rule with respect to the packet that refers the packet to a load balancing proxy;

c. performing a load balancing analysis at the load balancing proxy;

d. determining a load balancing rule based upon the load balancing analysis of step c; and

e. implementing the load balancing rule at the firewall.

8. The medium of claim 7, wherein said instructions are further adapted to be executed by a processor to perform the step of determining that a session is terminated and deleting a load balancing rule at the firewall.

9. A system for filtering a packet that is part of a session between applications. that negotiate a connection parameter, including the steps of:

a. means for receiving a packet at a firewall;

b. means for implementing a rule with respect to the packet that refers the packet to a load balancing proxy;

c. means for performing a load balancing analysis at the load balancing proxy;

d. means for determining a load balancing rule based upon the load balancing analysis of step c; and

e. means for implementing the load balancing rule at the firewall.

10. The system of claim 9, further comprising means for detecting if a session is terminated and means for deleting a rule.