interim commit

dbutils.c

@@ -2288,7 +2288,8 @@ get_voting_status(PGconn *conn)
 	return voting_status;
 }
 
-int	request_vote(PGconn *conn, int this_node_id, int this_node_priority, XLogRecPtr last_wal_receive_lsn)
+int
+request_vote(PGconn *conn, t_node_info *this_node, t_node_info *other_node, XLogRecPtr last_wal_receive_lsn)
 {
 	PQExpBufferData	  query;
 	PGresult   *res;
@@ -2298,7 +2299,7 @@ int	request_vote(PGconn *conn, int this_node_id, int this_node_priority, XLogRec
 
 	appendPQExpBuffer(&query,
 					  "SELECT repmgr.request_vote(%i, '%X/%X'::pg_lsn)",
-					  this_node_id,
+					  this_node->node_id,
 					  (uint32) (last_wal_receive_lsn >> 32),
 					  (uint32) last_wal_receive_lsn);
 
@@ -2311,7 +2312,41 @@ int	request_vote(PGconn *conn, int this_node_id, int this_node_priority, XLogRec
 	log_debug("XXX lsn_diff %i", lsn_diff);
 
 	PQclear(res);
-	return lsn_diff;
+
+	/* we're ahead */
+	if (lsn_diff > 0)
+	{
+		log_debug("this node is ahead");
+		return 1;
+	}
+
+	/* other node is ahead */
+	if (lsn_diff < 0)
+	{
+		log_debug("other node is ahead");
+		return 0;
+	}
+
+	/* tiebreak */
+
+	/* we're higher priority */
+	if (this_node->priority > other_node->priority)
+	{
+		log_debug("this node has higher priority");
+		return 1;
+	}
+
+	/* still tiebreak - decide by node_id */
+	if (this_node->node_id < other_node->node_id)
+	{
+		log_debug("this node has lower id");
+		return 1;
+	}
+	log_debug("other node wins");
+
+
+	/* we lose */
+	return 0;
 }
 
 

dbutils.h

@@ -246,7 +246,8 @@ bool		is_server_available(const char *conninfo);
 
 /* node voting functions */
 NodeVotingStatus get_voting_status(PGconn *conn);
-int		    request_vote(PGconn *conn, int this_node_id, int this_node_priority, XLogRecPtr last_wal_receive_lsn);
+int	request_vote(PGconn *conn, t_node_info *this_node, t_node_info *other_node, XLogRecPtr last_wal_receive_lsn);
+
 
 /* replication status functions */
 

repmgr.c

@@ -165,12 +165,14 @@ request_vote(PG_FUNCTION_ARGS)
 	initStringInfo(&query);
 	appendStringInfo(
 		&query,
-		"SELECT '%X/%X'::pg_lsn - pg_catalog.pg_last_wal_receive_lsn()::pg_lsn",
+		"SELECT ('%X/%X'::pg_lsn - pg_catalog.pg_last_wal_receive_lsn()::pg_lsn)::INT",
 		(uint32) (requesting_node_last_lsn >> 32),
 		(uint32) requesting_node_last_lsn);
 
-	ret = SPI_execute(query.data, false, 0);
+	elog(INFO, "query: %s", query.data);
+	ret = SPI_execute(query.data, true, 0);
 
+	// xxx handle errors
 	lsn_diff = DatumGetInt32(SPI_getbinval(SPI_tuptable->vals[0],
 										   SPI_tuptable->tupdesc,
 										   1, &isnull));

repmgrd.c

@@ -599,7 +599,7 @@ do_election(void)
 		cell->node_info->is_visible = false;
 
 		// XXX handle witness-barman
-		cell->node_info->conn = establish_db_connection(local_node_info.conninfo, false);
+		cell->node_info->conn = establish_db_connection(cell->node_info->conninfo, false);
 
 		if (PQstatus(cell->node_info->conn) != CONNECTION_OK)
 		{
@@ -628,12 +628,13 @@ do_election(void)
 
 	for (cell = standby_nodes.head; cell; cell = cell->next)
 	{
+		log_debug("checking node %i...", cell->node_info->node_id);
 		/* ignore unreachable nodes */
 		if (cell->node_info->is_visible == false)
 			continue;
 		votes_for_me += request_vote(cell->node_info->conn,
-									 local_node_info.node_id,
-									 local_node_info.priority,
+									 &local_node_info,
+									 cell->node_info,
 									 last_wal_receive_lsn);
 
 		PQfinish(cell->node_info->conn);