Resolution:
When a conn reports "failure_detected" or "End_of_file" then the error callback will be invoked.  The Error_detected means that either the Server_read_timeout expired followed by the Server_keep_alive_timeout also expiring (unable to read a message), or that the Server_write_timeout expired (unable to write a message).  The End_of_file error means that the process went to either read or write and discovered that the socket had already been closed by the server.  In either of these cases the error callback will be invoked which does a disconnect-warm followed by a connect-full to try and re-establish the connection.