I'm having some problem with a couple of servers having quite much amount of connections.
The servers just hangs for new network connections (although the functionality of load balancing in haproxy seems to work correct). I can not connect to ssh, and server cannot connect to other sockets.
I stayed connected with one console on screen to server. Then the error occurred I was not able to execute any command via screen.
# ls
-bash: fork: Cannot allocate memory
I could not execute "free -m" to show number of memory, but I got monitoring implemented which indicated, that the last value send was (RAM free, Buffers free, Swap free) (3597MB, 5793, 5783).
Server has many TIME_WAIT connection in netstat despite I changes tcp_fin_timeout to 15 (9155 TIME_WAIT, 55 ESTABLISHED). I was only able to run ulimits -a
core file size (blocks, -c) 0
data seg size (kbytes, -d) unlimited
max nice (-e) 0
file size (blocks, -f) unlimited
pending signals (-i) 88064
max locked memory (kbytes, -l) 32
max memory size (kbytes, -m) unlimited
open files (-n) 1024
pipe size (512 bytes, -p) 8
POSIX message queues (bytes, -q) 819200
max rt priority (-r) 0
stack size (kbytes, -s) 10240
cpu time (seconds, -t) unlimited
max user processes (-u) 88064
virtual memory (kbytes, -v) unlimited
file locks (-x) unlimited
PS. It's not a VPS. It's DELL.