Slow Forums: PF Under DDOS Attack

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Seems like it is not the first time when there is a (routing?) problem at 66.228.118.190.

Sometimes pings to PF get through, sometimes they don't, but I can't reach PF by traceroute and I can't post/read without a proxy.
 
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I had similar problems with 66.228.118.186 last Saturday.
 
I have Avast and I have not seen any popups when visiting PF.
 
Sunday afternoon/evening, PF died for me. I don't know if this was a widespread issue or if there were issues on the path between here and there.
 
Is it just me, or is the forum slow today? For most of the time it goes OK, but then for a minute or two it freezes.
 
Borek said:
Is it just me, or is the forum slow today? For most of the time it goes OK, but then for a minute or two it freezes.

Right now the forum is responsive.
But earlier today I got a couple of gateway timeouts that other people apparently didn't have.
When I watched what my browser was doing before a timeout, I saw that it happened when it was accessing mathjax.org...
I'm not sure yet however, that mathjax.org is the reason...
 
I like Serena said:
Right now the forum is responsive.
But earlier today I got a couple of gateway timeouts that other people apparently didn't have.
When I watched what my browser was doing before a timeout, I saw that it happened when it was accessing mathjax.org...
I'm not sure yet however, that mathjax.org is the reason...

Yep, I got that too, a few times now. I'm using Chrome, and I get a message I've never seen before that mentioned mathjax. Nothing is responsive, not even the cursor. Lasts about 10 seconds.
 
lisab said:
Yep, I got that too, a few times now. I'm using Chrome, and I get a message I've never seen before that mentioned mathjax. Nothing is responsive, not even the cursor. Lasts about 10 seconds.

please record the message next time it appears, thanks!
 
Greg Bernhardt said:
please record the message next time it appears, thanks!

It was only a couple seconds this time:

Loading [MathJax]/jax/output/HTML-CSS/jax.js

Happens when I open Random Thoughts.
 
lisab said:
It was only a couple seconds this time:

Loading [MathJax]/jax/output/HTML-CSS/jax.js

Happens when I open Random Thoughts.

This may be one of those case when you're getting the fonts from MathJax and they are a bit slow. I loaded the STIX fonts into my Win 7 Fonts folder and Firefox is lightning fast. Might be worth a try; if it can be done in Chrome.
 
I now get some sort of mathjax.js echo on a blank screen before the forum comes up.
 
Now I am getting 504 errors. Although I think that is not some problem with PF.
 

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mishrashubham said:
Now I am getting 504 errors. Although I think that is not some problem with PF.

This is PF problem, from what I remember nginex was added to help deal with DDOS attack, since then it sometimes gives 502 and 504 errors, at least for me. I have never seen these errors before DDOS attack.

IMHO MathJax problems are unrelated and appear when MathJax servers are not fast enough. Unfortunately Opera seems to deal incorrectly with such situations
 
DaveC426913 said:
I now get some sort of mathjax.js echo on a blank screen before the forum comes up.

can you elaborate? what are you doing when this happens? does it happen all the time?
 
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It happens anytime you enter a thread, sometimes it goes so quickly that you really have to be looking for it to see it. This is the message.

www.physicsforums.com/clientscript/mjsettings.js[/URL]

I started noticing it last week. I saw that you were discusing the issue Greg, or at least I thought that was what you were discussing. I'll pm you.
 
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MathJax is dependent on the Amazon CloudFront so there is little they can do in terms configuring that. One developer asked if anyone here would be willing to install a plugin that would collect data that would be useful in troubleshooting the loading problems. PM me if interested.
 
Code: 
borek@invincible ~ $ ./checkPF
PING physicsforums.com (74.86.200.109) 56(84) bytes of data.

--- physicsforums.com ping statistics ---
10 packets transmitted, 0 received, 100% packet loss, time 8998ms

traceroute to physicsforums.com (74.86.200.109), 15 hops max, 40 byte packets
 1  192.168.0.7 (192.168.0.7)  0.606 ms  0.568 ms  0.524 ms
 2  10.0.0.138 (10.0.0.138)  1.064 ms  0.990 ms  0.950 ms
 3  * * *
 4  xxxxx.tpnet.pl (xx.xx.xx.xx)  23.406 ms  23.614 ms  25.603 ms
 5  hbg-b2-link.telia.net (213.248.89.93)  40.144 ms  40.535 ms  40.570 ms
 6  hbg-bb2-link.telia.net (80.91.251.81)  46.344 ms  40.094 ms  39.173 ms
 7  nyk-bb2-link.telia.net (80.91.247.123)  125.381 ms nyk-bb2-link.telia.net (80.91.247.125)  123.475 ms  124.499 ms
 8  dls-bb1-link.telia.net (213.155.130.67)  165.859 ms dls-bb1-link.telia.net (213.155.130.209)  164.422 ms  165.928 ms
 9  te3-3.bbr02.eq01.dal01.networklayer.com (213.248.102.174)  169.799 ms  170.488 ms  170.192 ms
10  po6.dar02.sr01.dal01.networklayer.com (173.192.18.213)  170.019 ms  170.199 ms  170.734 ms
11  po2.fcr03.sr04.dal01.networklayer.com (66.228.118.190)  171.852 ms *  170.112 ms
12  * * *
13  * * *
14  * * *
15  * * *

For over two hours I was cut off (starting around 21:32 my time). And it had nothing to do with yesterdays situation :wink:
 
Again, my IP seems to be blocked, I can use some random free proxy to connect to PF, but for some reason server doesn't like my current address. Previous post was from the IP assigned by my ISP, the one that is blocked. Pings don't pass through. Seems like nobody else has problems.

I wonder if I am not blocked because some of IPs in my range are blacklisted? They are assigned dynamically once per 24h, so blocking them doesn't make much sense.

I will try to reset modem, perhaps I will get a new IP this way.
 
I like Serena said:
Did you get a different IP?
Because usually you get a "lease", meaning you'll get the same IP until the lease expires.

Completely different, 79.185.*.* vs 83.6.*.*.
 
Borek said:
Resetting modem helped, so there is no doubt it is IP related.
Throws net over Borek.

Sit, stay!

Oh wait, this isn't chat.
 
I like Serena said:
Did you get a different IP?
Because usually you get a "lease", meaning you'll get the same IP until the lease expires.

Borek said:
Completely different, 79.185.*.* vs 83.6.*.*.
If you have a dynamic IP address, you'll only keep that address until you disconnect from your ISP, the next time you log on, you will be given another IP address from you ISP. ILS, is that what you mean by a *lease*?
 
Evo said:
Throws net over Borek.

Sit, stay!

Oh wait, this isn't chat.

:)

Evo said:
If you have a dynamic IP address, you'll only keep that address until you disconnect from your ISP, the next time you log on, you will be given another IP address from you ISP. ILS, is that what you mean by a *lease*?

I was just verifying that there was indeed an actual change in IP before assuming that the old IP was blocked.
It seemed unlikely that Borek wouldn't have checked, but sure is sure. :)

If you're interested, the concept of a lease in this context is for instance explained here:
http://en.wikipedia.org/wiki/Dynamic_Host_Configuration_Protocol"
 
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I like Serena said:
:)



I was just verifying that there was indeed an actual change in IP before assuming that the old IP was blocked.
It seemed unlikely that Borek wouldn't have checked, but sure is sure. :)

If you're interested, the concept of a lease in this context is for instance explained here:
http://en.wikipedia.org/wiki/Dynamic_Host_Configuration_Protocol"
Ah, well I worked for AT&T that developed the internet for the US government. I worked on data networks from the early 70's. Never heard that term, we never used it. Someone posting on wikipedia wouldn't know that. <insert Aflac duck here> nah, nah. :-p

This must be a term that cropped up after the 70's. (Shows how old I am). :(
 
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If, for some horrible, unfathomable reason, you are on Windows, maybe try:
Code: 
ipconfig \release
ipconfig \renew
?
 
Evo said:
Ah, well I worked for AT&T that developed the internet for the US government.(

You must be smart!
 

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