swap storm and MaxMemInQueues
I experienced at a hardened Gentoo Linux exit relay 3 times in the last 2 weeks a swap storm, resulting in writing 10 till 12 GB to swap. This made the exit relay unresponsive for a longer time frame.
At least for the last time the swap storm seems to correlate with a lot of port scan connections over port 80 ("a lot" == 500 till 2000 and even more connections per seconds to a wide address range).
So I added today to torrc the line
MaxMemInQueues 4 GB
Anything else what I should do to narrow down the root cause ?
The linux kernel is a hardened 3.18.x linux, tor was 0.2.6.2-alpha (switched now to 2.6.3-alpha)