Wednesday
Mar162011
by 
Bishop Hill
Bishop Hill Commenting part 25
Mar 16, 2011 Blogs I've been asked to get more details of the commenting problems. If you are affected again could you
1. Note exactly what you were doing
2. Give details of the error message
3. Give browser type and version, OS and version and IP address
Reader Comments (38)
Can you set up and show an email address to send commenting problem messages to? If I'm having commenting problems, I won't be able to comment about them!
^ I'm obviously not having commenting problems today :p.
What a pity, this comment worked so I cant tell what went wrong :(
Email is:
this site name (all one word) and the domain is tiscali.co.uk
I've had intermittent problems, from fixed IP address using FF on Linux. ISP is Pipex/Tiscali/Talk-talk who whoever owns them this week.
The problems have mainly occurred after editing a comment - although I've no stats for this, I believe that simple comment-catcha-submit process works almost always, whereas an edited comment, esp. when edited more than once, gets a timeout on the submit.
I've also recently had intermittent problems with various other sites, which have gone away since I reverted to the old PIPEX name servers at 158.43.240.3 instead of the tiscali name server I was using.
As with steveta_uk this has been the only times a problem has arisen:
My second attempt failed when I tried to use preview.
The sequence of events which you might like to try is:
1. Write some ill informed off topic comment.
2. Hit "Preview Post"
3. Hit "Make Changes"
4. Hit "Preview Post"
5. Hit "Make Changes"
6. Get an error message stating the connection was reset.
I've capturing the network traffic so if you want a copy then email me.
When the final "Make Changes" in step 5 was hit it transmitted exactly the same POST request as the one in step 3. This is including the contents of the cookies and the content of the comment itself.
The web server sent a TCP RST packet to close the connection. This usually happens when the process on the server handling the request dies unexpectedly (ie crashes) but can happen if an intervening firewall has "forgotten" about the connection due to a long idle time. When your server closed the previously opened connection without response my browser opened a new connection and resent the POST request. Once again it received a TCP RST packet and because this occurred with a new connection it displayed the error message "connection reset".
This all leads me to believe the issue is not DNS or client related. The issue is with the software running on the web server.
For reference, here is the Agent string sent to the web server.
User-Agent: Mozilla/5.0 (X11; U; Linux i686; en-GB; rv:1.9.2.13) Gecko/20101203 SUSE/3.6.13-0.2.1 Firefox/3.6.13Bish,
I've created a brand new shiny website at squarespace (for free) and tested posting on it. It has exactly the same problems as posting here.
I was hoping that creating my own website I would have access to more detailed logs, but unfortunately the logs they provide are to basic.
Terry
That's extremely helpful. I've passed all this on to SQ.
Naturally, no problems so far today ;-)
But TerryS is surely correct:
So as he suggests, rather than a cache (message queue) overflow on the host server, it could be a firewall issue. What I do not understand is how the problem sometimes occurs with no prior - create post, send, 'connection reset'. No editing, no time for timeouts.
But an 'over-protective' or 'forgetful' firewall is an alternative explanation.
I'm all-but certain that the cause isn't cookies, or DNS, or OS or browser-specific.
Anyway, let's see what SQ comes up with once it finally conducts a thorough investigation.
As steveta_uk in all details bar ISP which in my case is outside UK.
"Give browser type and version, OS and version and IP address"
Anything else, What about my fuckin national insurance number?
Tell them to turn off the captchas for the coming week end. I still am convinced that it is in their queuing for comment creation and because everybody takes many seconds to find all those weird letter combinations, the queue gets choked. I find that the problem is worse during the weekends when there are more punters expressing themselves.
The problem is IN their code, not outside. They are just looking for an excuse to do nothing and praying that the mighty computer gods will magically make the problem go away. That will not happen.
I also believe that BBD had a good handle on it when he pointed out that forcing the IP to change by rebooting the router which gets his ISP to reassign a new dynamic IP indicates that their queuing is done by IP number. My ISP (ATT) has a fixed IP address for my router, which I don't want to reboot because it takes 10 minutes to restart. It is my DSL modem/ router/ firewall and should never be powered off. I even have it on a battery UPS.
So there you have the Don Pablo Challenge. Turn off the @##$*& Captchas and see if he is right.
I had problems a few days ago (before your server/DNS upgrade), and that was the usual failure after several edit / preview attempts. I can't remember exactly what message I got, but fortunately I had saved the text, so was able to keep retrying. However despite repeated attempts I couldn't get the post to register. I tried clearing Cookies, clearing Firefox's cache, closing & reloading FF, none of which helped. I then ran CCleaner which clears the DNS cache and still couldn't post. I gave up that night and switched the router off (as I do each night). The following morning after powering up again I was able to post at the first attempt. This suggests to me that the problem is IP related, as Tiscali/TalkTalk issue a new one each time I reboot the router.
For the record: XP Home SP3, Firefox 3.6.9, IP is currently 88.109.22.84, but I will be rebooting straight away as a security measure...
TerryS
OH THANK YOU SO VERY MUCH. I was about to shell out money to get a new copy of a TCP sniffer software and do exactly what you did. Yes, the #$(*$* server is sending the reset (RST) -- that was clear from how fast it happened. It use to happen in a few seconds, but now it takes about a minute so somebody has been play with the TCP stack. It's been 15 years since I done that, but my mind still remembers something of what I knew. You clearly are much more up-to-date than I and certainly have the correct tools.
BBD
I'm in your camp with regard to a firewall, I doubt it, but possible. I agree SQ needs to do a thorough investigation. Let them log in and post some comments this week end if they chose to ignore the Don Pablo Challenge -- which I suspect they will. However, if they turn it off and there are no problems during the weekend, they do have a very expensive problem to deal with.
I was posting a message and got a 'page not found' error instead of captcha. Lasted much of the afternoon yesterday. Using IE8, Windows XP.
IP 82.10.128.117
O/T
peter sissons is on Alan Titchmarsh show on ITV in a bit.
I tried to post a comm..
Actually, I'm with Don Pablo - I don't remember any problems before the captcha became full-time (as opposed to just posts with links).
It's better now than it was, though, IMO.
Your Bishopness: I've had only one tiny problem: I wrote a comment, posted it, and went away,before entering the Polish word the system called for--zxczypbt, or whatever. (Is very dirty word in Polish!) I came back 20 minutes or so later, entered the word, and found it was calling for a second input of alphabet soup, which I duly served. This resulted in a double post and the requisite self-flagellation. BFD.
browser type and version, OS and version and IP address: I'm running Opera Version 11.01, Build
1190, Platform Win32, System Windows XP, Home Edition, Version 2002, Service Pack 3. IP @ the little house in back.
And shouldn't His Excellency be using POPEX?
Hoping all is well with your bishopric,
Yours in Scepticism,
Jorge Kafkazar, BS, MS, PDQ, SPQR, QSDF
Windows 7, Chrome, IP
If you review change more than once say within 5 mins, you get the server error:
Error 101 (net::ERR_CONNECTION_RESET): Unknown error.
Waiting for 5 mins, allows you to create the post.
This post encountered this exact problem...
Anyone notice that Monbiot has written a piece in favour of nuclear as the lesser of two evils (coal being the greater evil).
At least he didn't suggest we build windfarms.
He'll be on the Daily Politics with Andrew Neil tomorrow.
http://www.guardian.co.uk/environment/georgemonbiot/2011/mar/16/japan-nuclear-crisis-atomic-energy
Google Chrome version 10.0.648.134
Windows XP with Service Pack 3 installed
Tried posting last night with the following results:
Using preview
This webpage is not available
The webpage at http://bishophill.squarespace.com/process/CreateJournalEntryComment?moduleId=902845&entryId=10795149 might be temporarily down or it may have moved permanently to a new web address.
Error 101 (net::ERR_CONNECTION_RESET): Unknown error.
Using preview
This webpage is not available
The webpage at http://bishophill.squarespace.com/process/CreateJournalEntryComment?moduleId=902845&entryId=10795149 might be temporarily down or it may have moved permanently to a new web address.
Error 101 (net::ERR_CONNECTION_RESET): Unknown error.
In like Flint without preview.
This webpage is not available
The webpage at http://bishophill.squarespace.com/process/CreateJournalEntryComment?moduleId=902845&entryId=10795149 might be temporarily down or it may have moved permanently to a new web address.
Error 101 (net::ERR_CONNECTION_RESET): Unknown error.
Deleted cookies and restarted browser. Posting clean, no preview.
This webpage is not available
The webpage at http://bishophill.squarespace.com/process/CreateJournalEntryComment?moduleId=902845&entryId=10795149 might be temporarily down or it may have moved permanently to a new web address.
Error 101 (net::ERR_CONNECTION_RESET): Unknown error.
Re Don Pablo..
Grab this..
http://www.wireshark.org/
very useful tool and must-have in every net engineer's toolbox.
Off topic: you should have watched Mock the Week tonight Bish. They covered the 2035 IPCC "error". I wonder if anyone can YouTube a clip.
Atomic Hairdryer
Wireshark is very nice, particularly for the price. I use to use something quite like it written by a friend while he was recovering from a motorcycle accident and he ended up selling it it for $500 a copy. SGI bought my copy. However Wireshark seems to do anything I would need, and you are right, an absolute necessity to have.
Thanks for the pointer. I hope the boys at SQ download it as well and start using it.
Don Pablo
There are gucci alternatives, ie expensive but have more graphics or analysys features. As Wireshark's pretty much the standard sniffer though, there's a stack of add-ons for doing good (and occasionally bad) things.
From what TerryS has posted it sounds server side, especially if the server's sending the RST. Could still be a firewall proxying though but suspect a resource problem on the server and it closing sessions rather than buffering.
Atomic Hairdryer
My take as well. I suspect a queue problem because of the time captchas require from the user to respond. Get several thousand of them (SQ has more than BH as a client), each taking several seconds waiting for them to fill in funny letters and you can easily blow out your buffers for what is on hand.
Get enough threads going and your scheduler packs it in switching from one thread to the other in the hopes that something completed.
Naturally, I don't actually know what they do internally, but I have my suspicions. If I am right, they have three choices: 1) much more efficient code 2) more hardware 3) use the captchas only on posts that have links as they use to. I am betting on 3 for some reason. Care to gu€$$ why?
Don, I don't see why the captcha queue should be an issue.
All they need to hold is a hash of the message, the source IP, and the issued captcha string, but even if holding the raw message for maybe 5 minutes, data volumes are tiny.
If they are caching text while it's being previewed/edited that's just daft, but timeouts do occur if you take too long editing. So I reckon SQ are just bad programmers.
I haven't tested to see which POST information is sent at each state but I suspect that, between the Preview and Submit routines there is some POST data which is being dropped from the form.
My best guess: When the final submission is made (after previewing), the server detects that there is missing POST data, interprets this as a malformed comment submission/DOS attack, and quickly resets the connection in order to minimise the impact of the attack. The server handling comment submissions also bans the IP temporarily, which is why we have to wait some time (usually 20 or so minutes for me) before it will accept new comment submissions.
steveta_uk
You clearly understand how it should be done, but is it they way the did it? All I know for sure is the problem came about once they required captchas for everything, and second that BBD was forcing NAT to negotiate a new dynamic IP by rebooting his router. That suggests they build a queue for each IP. Of course IP address are actually partially in the header given the shortage of IPv4 addresses, however, my memory is a bit grey on that since I stopped working on NAT and all that 15 years ago.
As I said several times, this is not computer science rocket science. They teach this sort of stuff in Systems Programming 101.
Try the Don Pablo Challenge this weekend and see whether the old boy is daft or not.
Simon Hopkinson
An interesting possibility.
MacOS, Chrome - don't ask me which versions, probably the latest available ...
Message:
Thursday, 16.58 p.m.:
The webpage at http://bishophill.squarespace.com/process/CreateJournalEntryComment?moduleId=902845&entryId=10826341 might be temporarily down or it may have moved permanently to a new web address.
Error 101 (net::ERR_CONNECTION_RESET): Unknown error.
Happened when I clicked on the 'create pots' button, before the captchas.
OK now.
No idea why or what-for ...
I just got (at 6:19) the following:
Connection closed by remote server
You tried to access the address http://bishophill.squarespace.com/process/CreateJournalEntryComment?moduleId=902845&entryId=10846497, which is currently unavailable. Please make sure that the web address (URL) is correctly spelled and punctuated, then try reloading the page.
Using Opera, Win 2k, and fixed IP, although I doubt that has much bearing on the problem.
Of course, if it's still there, you won't get to read this...
Same again, just now. Especially when revising a post at the point of entering the captcha. And still happening, so can't send this at the time of composition!
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As I said several times, this is not computer science rocket science. They teach this sort of stuff in Systems Programming 101.
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