my firebird server hangs, I don't know thre reason because nothing is
reported in logs, I can give you ps output and tell that I am using
rfunc library and there are 30 connections every 5 seconds. Maybe
database needs some network tweaking? Iuse superserver version 1.5.1. It
hangs randomly one time per 12h approx.

ps afx output(see Rl state):
24209 ? S 0:00 /usr/lib/firebird2/bin/fbguard -f
24211 ? Rl 26:48 \_ /usr/lib/firebird2/bin/fbserver

What do you think about rfunc UDF library?

btw, rfunc is using ib_util_malloc function from libib_util.so from
firebird superserver 1.5.2 package which I installed separetly(I
couldn't find debian package containing this file), server is installed
from debian package.

What could you suggest?