PNAS IP blocked after using Zotero

sgoossens
After I added an article from the PNAS website to my library, I can't access the site for a while, because it says my IP is blocked due to too many requests to the server.
I save both a snapshot and the full text PDF of the article.
Is there a way to get around this blockade?
  • sybille
    Hi,
    Are you using the Fasterfox extension or any performance tweaks in your user.js file? One common tweak is to increase the following variable:
    network.http.max-connections-per-server

    If you look in about:config and see that this has been changed to something greater than 8, you can try resetting it to a lower number like 8 or 10.
    More information here:
    http://kb.mozillazine.org/Network.http.max-connections-per-server
    http://kb.mozillazine.org/Editing_configuration
  • sgoossens
    Thanks for the tip. I changed the value to 4, but my IP was blocked again. Any other solution?
  • dstillman
    edited September 23, 2007
    That would appear to be PNAS being a bit overzealous in its connection rate blocking. I got the same error on PNAS. I didn't have this problem on another HighWire-powered site.

    Perhaps we can get in touch with them and see if they can relax the algorithm a bit for our access pattern, at least for single-article saving.
  • short
    edited November 6, 2007
    I got blocked the same. Based on the information given when blocked "
    ...... we require that you configure your offline browser to request no more than one page per minute." I think the problem might be that, while archiving the page, zotero are also try to obtain some other bit and pieces from the same page.
    My solution is, in Zotero, Actions-->Preferences-->General-->Miscellaneous-->uncheck the box before "Automatically take snapshots when creating items from web pages"
  • dstillman
    edited November 7, 2007
    Yes, that's what causes it. There's not really another solution other than getting them to relax their connection limiting. You might try contacting them and inquiring about that.

    Here's the ticket: #778
  • pesho
    PNAS has updated the message that shows up after they block the access. Here is the interesting part (one pager per minute sounds a bit harsh):

    " "Offline browsers" can create too-frequent requests, especially if they haven't been configured properly. Here is an excerpt from our posted guidelines for offline browsers:

    If you are using one of the popular "offline browsers" that allow you to download content from a site and read it later, be aware that we impose one restriction on their use.

    In order for us to provide reliable, continuous, and timely access to this site for all readers, we require that you configure your offline browser to request no more than one page per minute.

    Be aware that non-compliance with this rule will result in your access to this site being blocked until you contact us and resolve the problem. If you repeatedly break this rule you will be permanently blocked from the site.

    Access to site pages via an Open Proxy Server is prohibited."
  • arodrigues
    Having the same problem with PNAS. Quite annoying. I am almost scared of downloading from PNAS now as I always get temporarily blocked and am wondering if they will end up considering me a recalcitrant criminal. Has anyone actually ever got "permanently blocked"? Any advances on the negotiations between Zotero and them?
  • arodrigues
    PS - I wrote to PNAS asking about this, will report on any developments...
  • pesho
    I wrote to PNAS on Jan 18th, and didn't get any response from them.

    Did you write to the editorial board or to the e-mail address that is in the "blocked" message?
  • arodrigues
    I wrote to the webmaster of their webpages. No answer either so far...
  • iayork
    I have been regularly blocked from PNAS; I didn't connect it with Zotero, but now I suspect that's the cause. I wrote to the webmaster two days ago and I did receive a response saying that they recognized that I was inappropriately blocked and they were looking in to it. I just wrote back to them, noting that I have Zotero.

    Does Zotero make a single request when getting its information, or does it make multiple requests? I had assumed it was a single request, but it in fact it makes more than one call then PNAS's response seems more reasonable (though still overreacting).
  • arodrigues
    It may make three requests at once: one to get the reference, another to capture a snapshot of the page and another to get the pdf. You can change this in the preferences, such that it only gets the reference, and then you can get the pdf and the snapshot separately as attachments. This avoids getting it blocked (if you take more than 1 min between requests) and that's what I do to avoid being blocked. But it is a waste as one of the nice things of Zotero is being able to capture everything with one click. The most difficult part is to actually remember to change the preferences ahead when downloading references from PNAS.
  • dstillman
    OK, looks like we were a bit too hasty with the diagnosis. The blocking problem was being triggered by a bug in the third-party (WebPageDump/ScrapBook) code we use to save snapshots, which was causing Zotero to make about 20 invalid requests for image files when saving a PNAS snapshot. PNAS's servers block clients that make too many 404s too quickly, which isn't unreasonable.

    The bug is now fixed in the latest dev build of Zotero. Thanks to everyone who wrote into PNAS (who alerted us to the 404 issue).
  • arodrigues
    Yay! Great!
  • BioTeX
    awesome!
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