I need to count number of connections to php's cgi unix socket (created with spawn-fci). When nginx initiates a connection to cgi socket one of spawned php processes accepts this connection, processes input and outputs data. But number of processes is limited and i want to be able to monitor amount of free processes. I tried all available tools (netstat, sockstat even lsof) but it seems there is no way to determine how many active connections from nginx to unix socket. Please advise.