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www.imslp.org resolving to wrong IP address in Europe

Posted: Sun Sep 20, 2009 12:25 pm
by Peter
Feldmahler, since the last two weeks (since the last planned downtime?) I experience regular times when the server is unreachable. They are mostly short, when checking back after one hour it's over. Are you aware of this? Is anyone else experiencing this?

Re: Regular downtime

Posted: Sun Sep 20, 2009 5:30 pm
by Hobbypianist
Same happened to me when I was logged in some days ago and also today, just about 45 min. ago. FireFox tried to connect to imslp.org but server was not available. Only a few minutes later everything was ok again.

Re: Regular downtime

Posted: Sun Sep 20, 2009 6:26 pm
by daphnis
I can't say I've experienced any of these downtimes that I recall. Aside from the nightly maintenance downtimes (occuring around midnight-1am EST) I've not noticed anything unusual.

Re: Regular downtime

Posted: Mon Sep 21, 2009 12:26 am
by imslp
Aside from nightly maintenance that Daphnis referred to (which should only last 2 minutes, and you will see a page saying this), there should be no other downtime.

It would be extremely helpful to me for you to do the following:
1. Experience downtime (when you do)
2. Do an immediate traceroute of IMSLP.ORG
3. Check if IMSLP.ORG is still down after traceroute
4. If it is still down, post traceroute result here. Otherwise, post a note saying what happened.

Google "traceroute" if you don't know how to do it. A traceroute report is usually the first thing a server admin will ask you to give, so it may be handy to know how to do it in any case. If you know how to read the output, it will also usually tell you whether the problem is on your side or the server side.

Re: Regular downtime

Posted: Mon Sep 21, 2009 7:50 am
by Peter
Today, 9:40 AM CET, firefox says: time-out

Traceren van de route naar http://www.imslp.org [64.202.189.170]
via maximaal 30 hops:

1 1 ms <1 ms 4 ms 157.193.67.254
2 1 ms 1 ms 1 ms rtr-inter-gw138.ugent.be [157.193.138.25]
3 * * * Time-out bij opdracht.
4 * * * Time-out bij opdracht.
5 * * * Time-out bij opdracht.
6 * * * Time-out bij opdracht.
7 * * * Time-out bij opdracht.
8 * etc

the second hop is the university's gateway. however, traceroute command seems to blocked here because traces to other servers (eg google) also stop at the third hop.

UPDATE: this time, it's longer than usual. at 12:30 CET still no connection.

Re: Regular downtime

Posted: Mon Sep 21, 2009 12:44 pm
by imslp
Well, that traceroute immediately told me what is wrong, and it was the same as my suspicion. There is a bad DNS cache record somewhere in Europe, and that bad record is affecting you. IMSLP.ORG's IP address should be 174.142.90.75, not 64.202.189.170 (in fact, you should be able to access the site if you replace IMSLP.ORG with the correct IP address in the URL). I do not know if this is an innocent error, or a malicious DNS poisoning (even the old server did not have that IP), but I am at the moment powerless to fix it, as the problem is technically not on my side. I am powerless to control how IMSLP.ORG's DNS record is cached by other servers.

But I do want to be kept up to date so that if there is a possibility of me fixing anything, I can jump on it. All unannounced downtime is suspect, as no reason for this should exist.

If you are able to clear the DNS cache on your computer, you should be able to access IMSLP.ORG as long as you don't get the bad DNS record again (Google for how to do this). Keep sending traceroutes (more importantly, the IP address) if you get further downtime, as I want to see what exactly is happening.

Re: Regular downtime

Posted: Mon Sep 21, 2009 1:00 pm
by Peter
Thanks for your help. Indeed, when entering the correct IP, Renoir's girls are smiling at me. I will inform you when I have something new! The weird thing is however, sometimes I do connect correctly on this network.

Re: Regular downtime

Posted: Mon Sep 21, 2009 1:04 pm
by Peter
Update: I found the cause for the irregularity. http://www.imslp.org is resolving incorrectly; however, imslp.org (without the www) resolves the right IP. Different favorites and history entries in my browser caused me to one time visit with and the other time without www prefix.

Changing topic title and moving to help.

Re: www.imslp.org resolving to wrong IP address in Europe

Posted: Mon Sep 21, 2009 1:09 pm
by imslp
Good observation! This is also a bug that needs to be fixed, since www.imslp.org SHOULD redirect correctly to imslp.org. Now Wikipedia's complaint makes sense...

Re: www.imslp.org resolving to wrong IP address in Europe

Posted: Mon Sep 21, 2009 1:21 pm
by imslp
And fixed. Should take effect after 1 day.