Add connection messages for streaming replication. log_connections

was broken for a replication connection and no messages were
displayed on either standby or primary, at any debug level.
Connection messages needed to diagnose session drop/reconnect
events. Use LOG mode for now, discuss lowering in later releases.

Author: simonat2ndQuadrant

src/backend/replication/libpqwalreceiver/libpqwalreceiver.c

@@ -10,7 +10,7 @@
  *
  *
  * IDENTIFICATION
- *	  $PostgreSQL: pgsql/src/backend/replication/libpqwalreceiver/libpqwalreceiver.c,v 1.6 2010/03/19 17:51:42 sriggs Exp $
+ *	  $PostgreSQL: pgsql/src/backend/replication/libpqwalreceiver/libpqwalreceiver.c,v 1.7 2010/03/19 19:19:38 sriggs Exp $
  *
  *-------------------------------------------------------------------------
  */
@@ -157,6 +157,8 @@ libpqrcv_connect(char *conninfo, XLogRecPtr startpoint)
 	PQclear(res);
 
 	justconnected = true;
+	ereport(LOG,
+			(errmsg("streaming replication successfully connected to primary")));
 
 	return true;
 }

src/backend/utils/init/postinit.c

@@ -8,7 +8,7 @@
  *
  *
  * IDENTIFICATION
- *	  $PostgreSQL: pgsql/src/backend/utils/init/postinit.c,v 1.204 2010/02/26 02:01:13 momjian Exp $
+ *	  $PostgreSQL: pgsql/src/backend/utils/init/postinit.c,v 1.205 2010/03/19 19:19:38 sriggs Exp $
  *
  *
  *-------------------------------------------------------------------------
@@ -217,7 +217,14 @@ PerformAuthentication(Port *port)
 	if (!disable_sig_alarm(true))
 		elog(FATAL, "could not disable timer for authorization timeout");
 
-	if (Log_connections)
+	/*
+	 * Log connection for streaming replication even if Log_connections disabled.
+	 */
+	if (am_walsender)
+		ereport(LOG,
+				(errmsg("connection authorized: user=%s database=replication",
+						port->user_name)));
+	else if (Log_connections)
 		ereport(LOG,
 				(errmsg("connection authorized: user=%s database=%s",
 						port->user_name, port->database_name)));