Web switches provide traffic management to computer networks. The traffic management extends to packets received both from an outside network, such as the Internet, and from an internal network. A web switch may provide a series of software components to better handle the traffic. These components may include server load balancing (SLB), transparent cache switching (TCS), and firewall load balancing (FWLB). Server load balancing allows IP-based services to be transparently balanced across multiple servers. This distributed design prevents servers from getting overloaded. Transparent cache switching allows for distributed cache servers, and likewise prevents the cache servers from getting overloaded. Firewall load balancing increases the network's overall firewall performance by distributing the Internet traffic load across multiple firewalls.
Even though these software components are designed to manage traffic, the components themselves may become overwhelmed when traffic is heavy. For example, a server running TCS may become so overloaded with connections that it fails to properly handle packets sent through the connections. Traditional techniques for handling such a situation involve limiting the packet rate. This involves monitoring the number of packets received in short intervals, and dropping or redirecting packets if the number exceeds a threshold value. Unfortunately, for traffic management components, the number of packets received is not a direct predictor of when the components will become overloaded. These traffic management components are more likely to become overloaded when new connections are being established too quickly, as opposed to when new packets are coming in over those connections.
What is needed is a solution to better handle increased traffic to traffic management components.