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That's what my host is telling me...no blacklists or blocking are in place. I'm hoping they'll look at the tracert but so far there is no active blocking on my end.
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It doesn't look like a block or a routing problem since ping times are OK. Even when I ssh to that server the first part of the key exchange seems OK, it's the second phase which is slow. My bet is still on this being a DNS issue since it happened about the time we had a big DNS restructuring. Our internal IPs (which is what your server will see) don't have an entry in our external DNS, but maybe something on the seqanswers server is taking a long time to figure that out.
Could you try doing a DNS lookup on the IP I listed above on the server and see if it returns in a reasonable time? If it's not that I'm stumped.
[Writing this from home - where using the site is lovely and quick!]Comment
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DNS lookup on 149.155.147.36 is failing from my location (no matter what name servers I use, local or even with google's public name servers).
Unless SeqAnswers hosting provider is doing reverse name lookup (which would be unusual for just http connections)...Comment
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The lookup should fail (our internal IPs aren't in the external DNS), but it should fail quickly. My worry is that somehow it's taking a long time for the server to determine that there's no hostname to find.
Doing a reverse lookup might happen from a webserver if you're using name based logging or filtering.Comment
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The lookup is failing fairly instantly here. Perhaps not so for the SeqAnswers hosting provider.
Originally posted by simonandrews View PostComment
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OK, so here's a really odd thing. If I go to the archive section of the site at http://seqanswers.com/forums/archive/index.php then that's nice and quick and shows none of the problems we see on the rest of the site. This really does suggest that it's something on the server end rather than anything to do with the networking.Comment
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Just to prove the point - my last comment showed up on the archive site faster than the request which sent it returned on the main site. So the question is what is the main site doing which the archive site isn't?Comment
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I've done a bit more exploring and it turns out it's *only* the main pages which are slow (front page plus showthread.php). Everything else on the site I've tried is quick. This includes the archive site plus all images and CSS. It's something to do with the main dynamic script which has a problem with out domain.
It doesn't matter if we're authenticated or not. It's slow both ways.
It doesn't matter if we have javascript or CSS (or both) disabled.
The problem isn't tied to a specific machine, IP, browser or OS.
Hopefully knowing this might get us a bit closer to what the actual problem is?Comment
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Eco, are there any news regarding the connectivity problems? Unfortunately, SeqAnswers is still hideously slow... Thanks, FelixComment
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Guys apologies for letting this slip. I just received another detailed report from another of your colleagues at Babraham, but never from anywhere else.
Based on the details that another of your colleagues sent me (that this happens from your Cambridge site but not from another site), with their IP and time of access...I have a hunch that it's related to the banner impression logging. (which would make sense with what Simon has said since there are 4-6 banners on the front page).
If possible, can we try this experiment for relative loading times? For bonus points email (admin@) or PM me your IP and the times you tried this....
Front page (five banners): http://seqanswers.com
Forum index with one banner hosted by SEQanswers: http://seqanswers.com/forums/index.php
Forum index archive with ZERO banners hosted by SEQanswers: http://seqanswers.com/forums/archive/index.php
Forum with 2 banners: http://seqanswers.com/forums/forumdisplay.php?f=18
Same forum in index (0 banners): http://seqanswers.com/forums/archive....php/f-18.html
The ad display and impression logging seem to be taking extraordinarily long (~30 sec per banner) for your ip range (everywhere else it's milliseconds)....which I can't explain now but at least I have a place to start...Comment
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So this has got to be DNS related. I am unable to nslookup any ip from the Cambridge range (149.155.144.0 - 149.155.151.255)...getting SERVFAIL from both from googles DNS and my ISP's DNS. It takes quite a bit longer for the lookup to fail from my ISP's DNS (21 sec) vs. from googles DNS (4.2 sec) ...that must be what's going on.
The Rothamsted (sister site that supposedly works fine...149.155.16.0 - 149.155.23.255.) gives NXDOMAIN responses from both sources in <<<1 sec.
Sounds like we're on to something. Will file another ticket.Comment
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My knowledge of DNS is not great, but I know that none of our internal IPs are in our external DNS so we don't expect the lookups to work, but I don't know if SERVFAIL or NXDOMAIN is the correct response.Originally posted by ECO View Post
It's odd that you say it takes several seconds to fail on google's DNS since that's what I use too, and mine returns almost immediately.
Hopefully we're getting to the root of the problem though. I'll point out technical people to this thread so they can see if there's anything broken on our end.Code:$ time host 149.155.147.36 Host 36.147.155.149.in-addr.arpa not found: 2(SERVFAIL) real 0m0.115s user 0m0.013s sys 0m0.005s
Thanks for looking into this again.Comment
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Just wanted to let you know that following some DNS changes by our IT people here SeqAnswers is back and working properly again!
Thanks for your help in getting to the bottom of this.
Simon.Comment
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