Ok, thanks for ideas - many new things to test. So far no luck.
Too bad i don't have first-hand access to any of the client machines who *do* have this problem.
Next, I will go and switch the ethernet cable to a different slot on the router - kind of desperate, I know.
Some more details: - this web server is a xen virtual guest system, with CentOS 5.4 - the problem surfaced yesterday morning (6th of May), after I had migrated all these web sites from an old Fedora box to this new CentOS system
Does the problem affect other xen systems on the same box? I haven't tested this yet (I cannot reproduce the error).
You could test yourself if you can see http://62.236.221.71 (the problem system) http://62.236.221.78 (another guest on the same xen host)
If someone *cannot* see the 1st one, then it would be interesting to know if (s)he can see the 2nd one or not.
- Jussi
On 6.5.2010 22.00, Benjamin Franz wrote:
On 05/06/2010 11:42 AM, Ryan Manikowski wrote:
Notice the op posted they get timeouts even when going directly to a numerical address (if the apache server is configured to respond to *:80 it should at least display something)
Try using telnet from a client machine that can not connect.
e.g. telnet host.name.here 80
or
telnet xx.xxx.xxx.xxx 80
Try a few times and see if you're getting a timeout or if it connects every time. Run tcpdump on the apache server while sending the connection requests and see if the connection attempts show up at all. If they do not, then it's a network problem.
Try running 'ab' (the apache bench tool - see 'man ab' for how to use it) against your server and see if you can provoke the timeouts. If you can, then you are probably not configured to handle many quick connections and should check (1) httpd.conf to make sure you don't have an excessively low setting for 'MaxClients' or (2) a too low setting for max open filehandles. Look in /etc/security/limits.conf - you should have a line reading something similar to:
- nofile 64000
somewhere in it to raise the max number of open files. Busy web servers need lots of filehandles.
-- Benjamin Franz
-- Benjamin Franz
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