milter-greylist-1.3.3 is out
2004-05-25 by Emmanuel Dreyfus
Hello everybody First I'd like to thank Dan Hollis for taking care of this list, I'm sure it will be a usefull place for improving milter-greylist. milter-greylist-1.3.3 is now available from http://hcpnet.free.fr/milter-greylist I was planning major improvements in this release with the introduction of a Berkeley DB backend. The code was mostly written on monday, when I realized that if we wanted to keep the same level of reliability, migrating to a Berkeley DB backend would not buy any performance improvements. The problem is that when a crash occurs, we can end up with a corrupted DB. In order to avoid loosing the whole database in such a situation, I had to code a text dump at regular interval. Should the DB get corrupted, we could reload from the text dump. In order to take care of any situation, the text dump should be performed on any change. This brings us to the original situation: a compelte trade of performance for the sake of reliability. So I decided to throw away the Berkeley DB code (it's available from the CVS, just in case someone want to start it over some day). In order to handle the performance problem, the text dump can now be scheduled on a regular time interval instead of on each change. A new config file parameter called dumpfreq can be used for that. You just set it to the delay you want between text dumps. It defaults to 10mn. Shorter, you trade performances for reliability, higher, you trade performances for reliability. Note that reliability here just mean that if the machine crash, you loose the entries of the greylist that were made since the last dump. This just mean some message that should have been accepted will bounce one more time: you just get an additionnal delay in mail delivery. Two special values are available: -1 means never dump to a text file, which will result into a blazingly fast implementation (do that if you have some special feeling that the system will never crash or experience a power outtage), and 0 means to dump on every change, like it was the case before. For thes sceptical, Matthiew Herrb has been running a patched milter-greylist that dumps every minute on a high volume mail server and it seems to run just fine. Now, big question: is yahoogroups mail server SMTP compliant, or will all our greylist filter bounce this message forever because of some odd behavior? :) -- Emmanuel Dreyfus manu@...