Mailman performance issues

So I run the Atlanta Linux Enthuisasts’ list on mailman. Recently the server has been running loads between 5 and 8 – way more than it should be. Doing a top showed python using most of my CPU. I tracked it back to mailman and the config.pck file which as 50M.

The problem came about due to spam sent to the ale-* administrative addresses. Each time a spammer sent an email to that list, it would add an entry to the hold_and_cmd_autoresponses variable in the config.pck file. Every time python needs to access the ale config, it had to decrypt the config.pck file which uses lots of CPU.

The solution is to overwrite that vaiable with a null. Its possible doing this could break someone trying to subscribe to the list, but eh, its a free list, they can re-try.

Create a file with the following in it:

hold_and_cmd_autoresponses={}

then run the following command from your mailman root:

bin/config_list -i /tmp/foo ale

/tmp/foo is the file I created and ale is the list I needed to fix. It dropped my 50M config.pck to 1.8M and my load issues have gone down dramatically.