Dynamic HTTP load balancing

• US 8,412,807 B2
• Filed: 07/19/2012
• Issued: 04/02/2013
• Est. Priority Date: 07/24/2001
• Status: Expired due to Fees

• Current Assignee: International Business Machines Corporation
• Original Assignee: International Business Machines Corporation
• Inventors: DeLima, Roberto, Lanzen, Craig A.
• Primary Examiner(s): WINDER, PATRICE L
• Application Number:
  US13/552,644
• Publication Number:
  US 20120284411A1
• Time in Patent Office: 257 Days
• Field of Search: 709220-222, 709/226
• US Class Current: 709/222
• CPC Class Codes: H04L 41/0803 Configuration setting
• CPC Class Codes: H04L 41/0823 characterised by the purposes of a change of settings, e.g. optimising configuration for enhancing reliability for optimising operational conditions of wireless networks H04W24/02
• CPC Class Codes: H04L 41/0846 based on copy from other elements
• CPC Class Codes: H04L 41/0856 by backing up or archiving configuration information
• CPC Class Codes: H04L 41/0869 Validating the configuration within one network element
• CPC Class Codes: H04L 41/5009 Determining service level performance parameters or violations of service level contracts, e.g. violations of agreed response time or mean time between failures [MTBF]
• CPC Class Codes: H04L 41/5054 Automatic deployment of services triggered by the service manager, e.g. service implementation by automatic configuration of network components
• CPC Class Codes: H04L 67/02 based on web technology, e.g. hypertext transfer protocol [HTTP]
• 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 67/1014 based on the content of a request
• CPC Class Codes: H04L 67/1023 based on a hash applied to IP addresses or costs
• CPC Class Codes: H04L 67/14 Session management for real-time applications in data packet communications networks H04L65/1066
• CPC Class Codes: H04L 67/142 Managing session states for stateless protocols; Signalling session states; State transitions; Keeping-state mechanisms
• CPC Class Codes: H04L 67/34 involving the movement of software or configuration parameters network booting or remote initial program loading [RIPL] G06F9/4416
• CPC Class Codes: H04L 69/329 in the application layer [OSI layer 7]
• CPC Class Codes: H04L 9/40 Network security protocols

Abstract

The invention is a method and apparatus for facilitating facilitates load balancing in a server farm. In accordance with various aspects of the invention, all of the information about each server necessary for a load balancing program to define and execute a load balancing algorithm is stored at a predetermined URL for each server. The load balancer can query the predefined URL, which returns the necessary information. The load balancer then dynamically configures the load balancing algorithm in accordance with the returned information.

Claims

1. A method of configuring a load balancing program in a load balancer to dispatch client requests to servers in a cluster, the method comprising the steps of:

making an electronic record of a plurality of other servers available for adding to the cluster, the electronic record including a plurality of network addresses of the respective plurality of other servers; and

subsequently;

the load balancer detecting that the cluster cannot handle the client requests with specified performance, and in response;

the load balancer automatically polling one of the other servers at its network address obtained from the electronic record to request a configuration file containing parameters to configure the load balancer for bringing the one other server on-line in the cluster to handle client requests; and

the load balancer automatically configuring the load balancing program for the cluster to add the one other server to the cluster in accordance with the parameters contained in the configuration file.

2. The method of claim 1 wherein the load balancer configures the load balancing program for the other server based on content-based dispatching rules obtained from the configuration file.

3. The method of claim 1 wherein the load balancer configures the load balancing program for the other server to include an address of health information for the other server obtained from the configuration file, and the load balancing program subsequently queries the health of the other server via the address to determine whether the other server is able to handle a client request.

4. The method of claim 1 wherein the load balancer configures the load balancing program for the other server based on time-of-day rules obtained from the configuration file.

5. The method of claim 1 wherein the load balancer configures the load balancing program for the other server based on session affinity rules or cookie affinity rules obtained from the configuration file.

6. A computer program product for configuring a load balancing program in a load balancer to dispatch client requests to servers in a cluster, the computer program product comprising:

one or more computer-readable non-transitory storage devices and program instructions stored on at least one of the one or more storage devices, the program instructions comprising;

program instructions to electronically record addresses of a plurality of other servers available for adding to the cluster;

program instructions to subsequently detect that the cluster cannot handle the client requests with specified performance; and

program instructions, responsive to the detection that the cluster cannot handle the client requests with specified performance, to automatically poll one of the other servers at its network address obtained from the electronic record to request a configuration file containing parameters to configure the load balancer for bringing the one other server on-line in the cluster to handle client requests, and automatically configure the load balancing program for the cluster to add the one other server to the cluster in accordance with the parameters obtained from the configuration file.

7. The computer program product of claim 6 wherein the configuring program instructions configure the load balancing program for the other server based on content-based dispatching rules obtained from the configuration file.

8. The computer program product of claim 6 wherein the configuring program instructions configure the load balancing program for the other server to include an address of health information for the other server obtained from the configuration file, and the load balancing program subsequently queries the health of the other server via the address to determine whether the other server is able to handle a client request.

9. The computer program product of claim 6 wherein the configuring program instructions configure the load balancing program for the other server based on time-of-day rules obtained from the configuration file.

10. The computer program product of claim 6 wherein the configuring program instructions configure the load balancing program for the other server based on session affinity rules or cookie affinity rules obtained from the configuration file.

11. A load balancer computer for configuring a load balancing program in the load balancer computer to dispatch client requests to servers in a cluster, the computer comprising:

one or more computer-readable non-transitory storage devices and program instructions stored on at least one of the one or more storage devices, the program instructions comprising;

program instructions to electronically record addresses of a plurality of other servers available for adding to the cluster;

program instructions to subsequently detect that the cluster cannot handle the client requests with specified performance; and

program instructions, responsive to the detection that the cluster cannot handle the client requests with specified performance, to automatically poll one of the other servers at its network address obtained from the electronic record to request a configuration file containing parameters to configure the load balancer for bringing the one other server on-line in the cluster to handle client requests, and automatically configure the load balancing program for the cluster to add the one other server to the cluster in accordance with the parameters obtained from the configuration file.

12. The load balancer computer of claim 11 wherein the configuring program instructions configure the load balancing program for the other server based on content-based dispatching rules obtained from the configuration file.

13. The load balancer computer of claim 11 wherein the configuring program instructions configure the load balancing program for the other server to include an address of health information for the other server obtained from the configuration file, and the load balancing program subsequently queries the health of the other server via the address to determine whether the other server is able to handle a client request.

14. The load balancer computer of claim 11 wherein the configuring program instructions configure the load balancing program for the other server based on time-of-day rules obtained from the configuration file.

15. The load balancer computer of claim 11 wherein the configuring program instructions configure the load balancing program for the other server based on session affinity rules or cookie affinity rules obtained from the configuration file.