A. Field of the Invention
The present invention relates generally to computer networks, and more particularly, to resource management of server computers in a public network, such as the Internet.
B. Description of Related Art
Network computer servers, such as computers that transmit HTML (HyperText Markup Language) documents to client computing devices on the Internet, may interact and receive data requests from many different end-users. It is frequently important that these computer servers maintain high levels of uptime. For example, if a server for an e-commerce site fails to respond to user requests, the site may lose sales.
There are many reasons why a server, or a group of servers, may fail. For example, the server may experience software or hardware errors that cause the server to fail. Additionally, the server may experience resource-related problems, such as too many users trying to simultaneously communicate with the server. Such resource-related problems can be “natural” resource problems in which too many bona fide users are trying to access the system simultaneously or malicious problems such as denial of service (DoS) or distributed denial of service (DDoS) attacks. In a DoS or DDoS attack, a compromised system or a multitude of compromised systems flood a server with incoming messages in an attempt to overwhelm the available server resources. Legitimate users of the server may then be denied service by the server due to the overload of its resources.
Accordingly, server system availability is an important concern for network servers, such as Internet servers. Conventional hardware solutions, such as clustering and failover, offer some assurances in this area by offering more resources to the users. However, these solutions can fail when faced with automated DoS and DDoS attacks that simply keep taking resources.
Accordingly, there is a need in the art to improve resource management in the face of attacks on system resources.