On Friday 07 May 2010 05:38:45 Jussi Hirvi wrote: > 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 > OK I can see the second one but not the first. I can also ping the second one but not the first. Tony > 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 > > > > > > > > _______________________________________________ > > CentOS mailing list > > CentOS at centos.org > > http://lists.centos.org/mailman/listinfo/centos > -- Chief Technical Officer. Tel: +353 061-202778 Dept. of Comp. Sci. University of Limerick.