Maybe I'm wrong, but the server is also using many memories for TCP cat /proc/net/sockstat sockets: used 13523 TCP: inuse 8612 orphan 49 tw 31196 alloc 8728 mem 18237 UDP: inuse 14 mem 6 UDPLITE: inuse 0 RAW: inuse 0 FRAG: inuse 0 memory 0 netstat -lataupen | wc -l 38780