Blog@Case News for July 2006

Trackback is Back

You may have noticed that the trackback functionality of the blog system has been disabled for some time now. We have been engaged in an epic struggle with spammers, and while most of the spammy trackbacks were caught by the system, the sheer number of machines attempting to spam us caused an effective Denial of Service, and we were forced to disable trackbacks to keep the blog system operational.

Well, we're happy to announce we've turned the tide on the spammers and are now blocking those computers that attempt to repeatedly hit the system with trackback or comment spam. This should also reduce the amount of time you need to go in and spend effort marking icky comments and trackback as spam.

The new system has been running in a logging mode to gather metrics on what would be acceptable use versus spammer characteristics. The heuristics used are fairly draconian. A computer is permanently banned from reaching the blog system if they:

  • Attempt to submit 5 comments in any 90 minute period and all of those comments end up labelled "moderated" by the other spam measures.
  • Attempt to submit 2 comments in any 4 hour period from an IP address whose earlier comments were marked as spam by a user of the blog system.
  • Attempt to trackback to an entry on the blog system 3 times in 90 minute period.
  • Attempt any trackback from an IP address whose earlier trackback(s) were marked as spam by a user of the blog system.

If a computer does get blocked, they are given a message telling them so and asking them to email blog-admin@case.edu to get their computer unblocked.

As of right now, the new banning system has been running for under 24 hours and over 1000 IPs have been banned.

We're winning the war! Go off and trackback to your heart's content!

Posted July 21, 2006 12:37 PM