One of the features that keeps Wizbang running smoothly is the SpamLookup service that is a part of our blogging software. I actually use three products – SpamLookup, Akismet, and AutoBan to automate our spam prevention process. The three together work great; catching, removing, and banning the spammers automatically.
All of the sudden this week the comment process at all of the Wizbang sites went from blazingly fast to horrifyingly slow. There wasn’t any good explanation since we’re not really doing anything differently behind the scenes. After ruling out speed and server performance issues I went to work breaking down the comment submission process and all the dependencies. It turns out that the built-in SpamLookup service (which is on by default) uses a three different blacklist services for its lookups: bsb.spamlookup.net, opm.blitzed.org , and sc.surbl.org. A little investigation lead to this:
Please stop querying the opm.blitzed.org zone. As of May 2007 in order to reduce query load on our servers opm.blitzed.org is pointing at a blackholed nameserver — queries will take a long time and result in a SERVFAIL.
The SpamLookup service was timing out (based on our observation it waited 20-30 seconds) trying to connect to opm.blitzed.org before the comment was successfully submitted.
I believe this affects all Movable Type blogs (running version 3.2 and above of the software) unless they’ve disabled Spam Lookup (which is rare), so if you’ve got a Movable Type based installation open the SpamLookup – Lookups module and remove opm.blitzed.org from the list of services checked.
Once you do that commenting should be back to normal. Pass this along to other sites – their Movable Type installation is most likely broken, whether they realize it or not…
Update: I’ve confirmed this with the Movable Type developers. I’m not sure if they’re planning on making an announcement to their customer base, but given the amount of time I had to spend tracking down the problem and the likelihood that most of their customers are affected, they really should.