|Perl Monk, Perl Meditation|
Re^3: "Invisible" nodes (core)by tye (Sage)
|on Jan 04, 2012 at 00:04 UTC||Need Help??|
traceroute is likely of no use here. The variable of interest is which IP your browser is choosing to use at the time of the request for the hostname involved. As noted in that thread, more useful would be to look up the IPs associated with www.perlmonks.org and repeat the tests directly against the IPs and report which of them have and don't have the problem.
I believe that the two major problems covered in that thread are already fixed (and fixed a long time ago).
Fairly rarely I notice that certain nodes cause a Perl (inside mod_perl) core dump when viewed by certain people via certain web servers at certain times. When that happens, my browser gets a blank page in response. Sometimes I can make this symptom go away by restarting apache on that server. Sometimes the core dumps persist even after a restart but, again, only for certain nodes and only when viewed by certain people.
Switching from perlmonks.org to perlmonks.com might cause different behavior because at the time, your browser is choosing to use different IPs for those different host names (and not all of the servers are in a state where that problem happens). Or the change may be because you have a login cookie for one hostname but not for the other. The useful information is whether you are logged in or not and what IP the request went to. The host name is pretty much of no use at all, since I have no way of knowing what IP your browser was choosing to use for that hostname at that time.
When I run into the blank page problem and I can't be bothered to try restarting Apache (which is more work than I think it really should be), I can usually see the information I'm after by using a hostname that I don't have a login cookie for or by looking at the parent node in order to see the reply or by looking directly at the reply instead of at the parent.
This happens so rarely to me that I have not spent the likely great deal of time required to narrow down the problem further.