Tue Nov 25 10:23:47 PST 2003 — SpamAssassin Changes: In order improve the overall quality and performance of our primary anti-spam filters we’ve disabled one of it’s features; The AWL, or auto-whitelist, keeps track of all addresses that mail has been received from along with statistics about that senders mail profile. This information is used to shift a given message’s score to the senders mean. This can be an effective tool in helping reduce false positives, but, as implemented currently, it has a number of flaws. The most significant flaw is run away growth which eats into users’ disk quotas; it never deletes records from the database.
One of the side effects of the ever-increasing AWL database size is increased server IO load. This morning, the IO load generated by the AWL on freezer, the NetApp filer that they are stored on, was approaching 90% of the filer’s total capacity. As freezer slows down under these high load conditions it cascades to high load on the SpamAssassin servers, mail servers and results in unfiltered mail.
We are working on a major SpamAssassin upgrade that we expect to launch around the New Year. Hopefully, if we feel that the AWL is still a valuable feature of SpamAssassin, we’ll be able to improve and re-enable it at this time. -Kelsey