The SANS Internet Storm Center recommends that organizations running Web servers that are vulnerable to the tool s attack make some basic configuration changes to their servers to help mitigate the effects of the attack. The new attack uses a tool created by security researcher Robert Hansen, known as Rsnake, takes advantage of some characteristics of the Apache Web server to keep a number of. connections open for long periods, effectively denying service to legitimate users of the site. The analysts suggest that sites running Apache look at the TimeOut value, which defines the amount of time that Apache will wait for an HTTP GET request.
Source: https://threatpost.com/mitigating-slowloris-http-dos-attack-062209/72845/