US 7,404,211 B2
Systems and methods for protecting a server computer
Shin-ichi Kanno, Kanagawa-ken (Japan); and Masamichi Tateoka, Tokyo (Japan)
Assigned to Kabushiki Kaisha Toshiba, Tokyo (Japan)
Filed on Sep. 25, 2003, as Appl. No. 10/669,710.
Claims priority of application No. P2002-280289 (JP), filed on Sep. 26, 2002; and application No. P2003-071238 (JP), filed on Mar. 17, 2003.
Prior Publication US 2004/0064738 A1, Apr. 01, 2004
Int. Cl. G06F 11/00 (2006.01)
U.S. Cl. 726—22  [726/23; 726/24; 726/25] 14 Claims
OG exemplary drawing
 
1. A server computer protection apparatus for protecting a server computer against attacks, comprising:
a data request acceptance unit configured to accept data requests sent from client computers coupled to the server computer via the protection apparatus, as proxy for the server computer which is different and separate from the protection apparatus;
at least one request measurement unit configured to measure a number of data requests which have arrived from said client computers within a predetermined time period;
a response measurement unit configured to measure a number of responses which have been made from said server computer to said client computers within the predetermined time period;
at least one server load calculation unit configured to obtain a load state of said server computer by using measurements of said request measurement unit and said response measurement unit; and
a data request transfer unit configured to change a rate of the number of data requests based on the load state determined by said server load calculation unit,
wherein said server load calculation unit is configured to store said load state of said server computer;
wherein said server load calculation unit chances the value stored in accordance with a new load state of said server computer;
wherein, as said changed value exhibits a higher load, the rate of said number of the data requests which are to be transferred to said server computer is decreased by said data request transfer unit; and
wherein, as said changed value exhibits a lower load, the rate of said number of the data requests which are to be transferred to said server computer is increased by said data request transfer unit.