In TCP servers, I understand that a Connection Refused would either be because the The process stopped listening, by calling close on the server-socket (existing connections stay open, and new connections are refused), or The process ended, or The process did not accept connections frequently enough, so the backlog became full / the backlog was too small. What are the possible causes of ECONNREFUSED when attempting to connect to UNIX Domain Sockets . This question is to help me narrow down a MySQL connection mystery on a Solaris 10 configuration .

What causes ECONNREFUSED on UNIX Domain Sockets?

In TCP servers, I understand that a Connection Refused would either be because the

The process stopped listening, by calling close on the server-socket (existing connections stay open, and new connections are refused), or
The process ended, or
The process did not accept connections frequently enough, so the backlog became full / the backlog was too small.

What are the possible causes of ECONNREFUSED when attempting to connect to UNIX Domain Sockets.