Decrypting load balancing array system

• US 7,734,814 B2
• Filed: 03/03/2008
• Issued: 06/08/2010
• Est. Priority Date: 03/10/2000
• Status: Expired due to Term

• Current Assignee: Akamai Technologies, Inc.
• Original Assignee: Akamai Technologies, Inc.
• Inventors: Swildens, Eric Sven-Johan
• Primary Examiner(s): Patel; Haresh N
• Application Number:
  US12/041,562
• Publication Number:
  US 20090055552A1
• Time in Patent Office: 827 Days
• Field of Search: 709/238, 709217-228, 709200-203, 718/105
• US Class Current: 709/238
• CPC Class Codes: H04L 63/0471 applying encryption by an intermediary, e.g. receiving clear information at the intermediary and encrypting the received information at the intermediary before forwarding
• 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 67/1023 based on a hash applied to IP addresses or costs
• 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 9/40 Network security protocols

Abstract

A decrypting load balancing array system uses a Pentaflow approach to network traffic management that extends across an array of Decrypting Load Balancing Array (DLBA) servers sitting in front of back end Web servers. One of the DLBA servers acts as a scheduler for the array through which all incoming requests are routed. The scheduler routes and load balances the traffic to the other DLBA servers (including itself) in the array. Each DLBA server routes and load balances the incoming request packets to the appropriate back end Web servers. Responses to the requests from the back end Web servers are sent back to the DLBA server which forwards the response directly to the requesting client.

Claims

1. A method for routing packets through a decrypting load balancing array of servers across a network in a computer environment, the load balancing array of servers decrypting and encrypting SSL requests and performing SSL session scheduling, comprising:

requesting, by the scheduler, assignment of a virtual IP address to the scheduler, wherein incoming packets over a network from requesting clients destined for the load balancing array of servers are routed through the scheduler via the virtual IP address;

in response to receiving a request packet from a requesting client at a scheduler in a load balancing array of servers, the scheduler routing and load balancing the request packet to a load balancing server among the load balancing array of servers;

in response to receiving the request packet at the load balancing server, the load balancing server decrypting the response packet of an SSL session before routing and load balancing the request packet to a back end Web server among a cluster of back end Web servers, wherein the back end Web server'"'"'s response packet to the request packet is sent to the load balancing server;

in response to receiving the response packet at the load balancing server, the load balancing server encrypting the response packet of the SSL session before sending the response packet directly to the requesting client; and

prior to the sending step, having the load balancing server parse an outgoing markup language page in the response packet to identify given content served by a content delivery network and modify URLs for the given content in the markup language page so that the given content is served from the content delivery network in response to requests from requesting clients.

2. The method of claim 1, wherein the scheduler routes and load balances client requests to itself.

3. The method of claim 1, further comprising:

detecting failure of the scheduler; and

electing a load balancing server among the load balancing away of servers as a new scheduler.

4. The method of claim 1, wherein the scheduler detects failure of any load balancing servers among the load balancing array of servers, and wherein the scheduler stops routing packets to any failed load balancing servers.

5. The method of claim 1, wherein the load balancing server schedules sessions to back end Web servers based on a cookie or session ID.

6. The method of claim 1, wherein the load balancing server uses cookie injection to map a client to a specific back end Web server.

7. An apparatus for routing packets through a decrypting load balancing array of servers across a network in a computer environment, the load balancing array of servers decrypting and encrypting SSL requests and performing SSL session scheduling, comprising:

at least one processing unit;

a scheduler stored in a storage medium in a load balancing array of servers requests assignment of a virtual IP address to the scheduler, wherein incoming packets over a network from requesting clients destined for the load balancing array of servers are routed through the scheduler via the virtual IP address;

the scheduler, in response to receiving a request packet from a requesting client, routes and load balances the request packet to a load balancing server among the load balancing array of servers;

a load balancing server among the load balancing array of servers that, in response to receiving the request packet, first decrypts the response packet of an SSL session, and then routes and load balances the request packet to a back end Web server among a cluster of back end Web servers, wherein the back end Web server'"'"'s response packet to the request packet is sent to the load balancing server;

the load balancing server, in response to receiving the response packet, first encrypts the response packet of the SSL session and then sends the response packet directly to the requesting client; and

the load balancing server, prior to the sending of the response packet, parses an outgoing markup language page in the response packet to identify given content served by a content delivery network and modifies URLs for the given content in the markup language page so that the given content is served from the content delivery network in response to requests from requesting clients.

8. The apparatus of claim 7, wherein the scheduler routes and load balances client requests to itself.

9. The apparatus of claim 7, further comprising:

a module for detecting failure of the scheduler; and

a module for electing a load balancing server among the load balancing array of servers as a new scheduler.

10. The apparatus of claim 7, wherein the scheduler detects failure of any load balancing servers among the load balancing away of servers, and wherein the scheduler stops routing packets to any failed load balancing servers.

11. The apparatus of claim 7, wherein the load balancing server schedules sessions to back end Web servers based on a cookie or session ID.

12. The apparatus of claim 7, wherein the load balancing server uses cookie injection to map a client to a specific back end Web server.