Hi!
Storage discovery connector is part of not finished feature and can be safely ignored. Push connector used by nxapush command line tool to push DCI values through agent's connection with server. Both are using UNIX sockets, with file names /tmp/.nxagentd.push and /tmp/.nxagentd.sd. Most likely they was left on file system and owned by root - this is why agent cannot open them as non-root user.
Line
if (g_dwFlags & AF_SUBAGENT_LOADER)
determines two execution paths depending on agent mode - is it master agent (the default one) or external subagent loader. NetXMS agent can be divided into multiple processes usually run under different accounts - in that case one is a master and others are external subagent loaders. External loaders communicates with master using UNIX sockets.
Best regards,
Victor
