From http://httpd.apache.org/docs/2.4/mod/core.html#timeout "In mod_cgi, the length of time to wait for output from a CGI script." It is unclear whether it is about the time until the CGI script closes stdout or about the time until the first character from the CGI output appears. Please explain is it time till close of stdout or time till the first character appearing at the stdout of the script. Note that I've reported this question in a documentation bug: https://bz.apache.org/bugzilla/show_bug.cgi?id=60404