Virtual Domains

[Robert Dinse <nanook@eskimo.com>]

     This morning, the virtual domain server seemed to "stick" processes and
stop responding or very slowly respond to requests.

     The machine itself responded normally other than Apache.  There are no
errors in the logs nor indications of resource exhaustion however, I am aware
of some issues with Apache and the way it is presently compiled that can make
it vunerable to a denial of services attack that would exhibit these symptoms.

     I am going to re-compile it later today and attempt to correct this.
This has to do with the way threading is handled, and unfortunately there is
somewhat of a speed/robustness trade-off, which is to say that making it more
stable also entails using a signalling method that is not as fast but it may
not make a noticable difference given that the CPU load on this machine is not
high to begin with.

     Also, if anybody knows of any good web monitoring tools that actually can
check the response on port 80, I'd appreciate a pointer.  Right now I have a
script that checks to see if the process is still running, but it does not
detect this particular type of problem because the server is still "running". 

     I apologize for not responding to this sooner; but US West, in their
infinite wisdom, changed thier voice mail system so that when it pages you it
now puts some number in Bellevue in the page and I thought someone had just
gotten a wrong number.