[knot-dns-users] Knot memory usage

On a server with 16 GB of RAM, my instance of BIND can load my 5174 zones into memory and use around 13 GB. Knot didn't do so well. At some point while trying to XFR-in these zones, it hit the memory limit and the Linux out-of-memory killer came along and killed it. When I started it up again, it began loading zones in from the disk, but then appeared to go into some kind of loop, and the CPU usage was 100%. This is usually a sign that it is stuck in some kind of loop or deadlock. The only want to stop it is with a KILL signal (TERM doesn't work). The log didn't output anything. How can I help debug this? Do you have any numbers on how much RAM Knot will require given a bunch of zones? This would allow me to estimate how much RAM I will need in a server for the zones I have. Regards, Anand