Database load balancing for multi-tier computer systems

(54) DATABASE LOAD BALANCING FOR MULTI-TIER COMPUTER SYSTEMS

(76) Inventor: Homayoun Yousefi'zadeh, 14 Posada, Irvine, CA (US) 92614

( * ) Notice: Subject to any disclaimer, the term of this patent is extended or adjusted under 35 U.S.C. 154(b) by 0 days.

(21) Appl. No.: 09/565,777

(22) Filed: May 5, 2000

(51) Int. CI.7 G06F 15/16

(52) U.S. CI 709/203; 709/217; 709/226;

718/105; 707/10

(58) Field of Search 709/226, 203,

709/223-224,105, 241, 201, 217-219; 707/10;

718/105

(56) References Cited

U.S. PATENT DOCUMENTS

5,754,772 A * 5/1998 Leaf 709/203

6,085,198 A * 7/2000 Skinner et al 707/103 R

6,125,363 A * 9/2000 Buzzeo et al 707/100

6,134,594 A * 10/2000 Helland et al 709/203

6,175,869 Bl * 1/2001 Ahuja et al 709/226

6,209,029 Bl * 3/2001 Epstein et al 709/219

6,266,666 Bl * 7/2001 Ireland et al 707/10

6,286,104 Bl * 9/2001 Buhle et al 707/10

6,446,109 B2 * 9/2002 Gupta 709/203

* cited by examiner

Primary Examiner—Philip B. Tran

(57) ABSTRACT

A load balancing method and system for a transaction computer system having multiple database servers for at least one database, wherein database servers cooperate to provide a unified view of the data in the database. The method includes the steps of establishing connections to said multiple database servers for communicating with said database servers; and assigning transactions to respective ones of said multiple database servers to balance respective loads of said multiple database servers. Assigning each new transaction includes the steps of determining possible assignments of that new transaction to one or more of said multiple database servers, each said possible assignment to one of said multiple database servers being based on a load balancing scheme to balance respective loads of said multiple database servers; and assigning that new transaction to one of said multiple database servers as a function of said possible assignments of that new transaction, to balance respective loads of said multiple database servers.

39 Claims, 16 Drawing Sheets