"standby follow": check node system identifiers match

controldata.c

@@ -17,6 +17,25 @@
 
 static ControlFileInfo *get_controlfile(const char *DataDir);
 
+uint64
+get_system_identifier(const char *data_directory)
+{
+	ControlFileInfo *control_file_info;
+	uint64 system_identifier = UNKNOWN_SYSTEM_IDENTIFIER;
+
+	control_file_info = get_controlfile(data_directory);
+
+	if (control_file_info->control_file_processed == true)
+		system_identifier = control_file_info->control_file->system_identifier;
+	else
+		system_identifier = UNKNOWN_SYSTEM_IDENTIFIER;
+
+	pfree(control_file_info->control_file);
+	pfree(control_file_info);
+
+	return system_identifier;
+}
+
 DBState
 get_db_state(const char *data_directory)
 {
@@ -33,6 +52,7 @@ get_db_state(const char *data_directory)
 
 	pfree(control_file_info->control_file);
 	pfree(control_file_info);
+
 	return state;
 }
 

controldata.h

@@ -18,10 +18,10 @@ typedef struct
 	ControlFileData *control_file;
 } ControlFileInfo;
 
-DBState get_db_state(const char *data_directory);
+extern DBState get_db_state(const char *data_directory);
-const char * describe_db_state(DBState state);
+extern const char * describe_db_state(DBState state);
-int get_data_checksum_version(const char *data_directory);
+extern int get_data_checksum_version(const char *data_directory);
-
+extern uint64 get_system_identifier(const char *data_directory);
 extern XLogRecPtr get_latest_checkpoint_location(const char *data_directory);
 
 #endif /* _CONTROLDATA_H_ */

dbutils.c

@@ -115,6 +115,7 @@ _establish_db_connection(const char *conninfo, const bool exit_on_error, const b
 	if (parse_success == false)
 	{
 		log_error(_("unable to pass provided conninfo string:\n	 %s"), errmsg);
+		free_conninfo_params(&conninfo_params);
 		return NULL;
 	}
 
@@ -155,6 +156,7 @@ _establish_db_connection(const char *conninfo, const bool exit_on_error, const b
 		if (exit_on_error)
 		{
 			PQfinish(conn);
+			free_conninfo_params(&conninfo_params);
 			exit(ERR_DB_CONN);
 		}
 	}
@@ -170,11 +172,13 @@ _establish_db_connection(const char *conninfo, const bool exit_on_error, const b
 		if (exit_on_error)
 		{
 			PQfinish(conn);
+			free_conninfo_params(&conninfo_params);
 			exit(ERR_DB_CONN);
 		}
 	}
 
 	pfree(connection_string);
+	free_conninfo_params(&conninfo_params);
 
 	return conn;
 }
@@ -1284,6 +1288,8 @@ get_replication_info(PGconn *conn, ReplInfo *replication_info)
 	replication_info->last_wal_replay_lsn = parse_lsn(PQgetvalue(res, 0, 1));
 	strncpy(replication_info->replication_lag_time, PQgetvalue(res, 0, 3), MAXLEN);
 
+	PQclear(res);
+
 	return true;
 }
 
@@ -1478,11 +1484,11 @@ get_replication_lag_seconds(PGconn *conn)
 
 
 bool
-identify_system(PGconn *replconn, t_system_identification *identification)
+identify_system(PGconn *repl_conn, t_system_identification *identification)
 {
 	PGresult		 *res;
 
-	res = PQexec(replconn, "IDENTIFY_SYSTEM;");
+	res = PQexec(repl_conn, "IDENTIFY_SYSTEM;");
 
 	if (PQresultStatus(res) != PGRES_TUPLES_OK || !PQntuples(res))
 	{
@@ -2406,6 +2412,8 @@ get_node_replication_stats(PGconn *conn, t_node_info *node_info)
 	node_info->active_replication_slots = atoi(PQgetvalue(res, 0, 3));
 	node_info->inactive_replication_slots = atoi(PQgetvalue(res, 0, 4));
 
+	PQclear(res);
+
 	return;
 }
 

dbutils.h

@@ -345,7 +345,7 @@ RecoveryType get_recovery_type(PGconn *conn);
 int			 get_primary_node_id(PGconn *conn);
 bool		 can_use_pg_rewind(PGconn *conn, const char *data_directory, PQExpBufferData *reason);
 int 		 get_ready_archive_files(PGconn *conn, const char *data_directory);
-bool		 identify_system(PGconn *replconn, t_system_identification *identification);
+bool		 identify_system(PGconn *repl_conn, t_system_identification *identification);
 
 /* extension functions */
 ExtensionStatus get_repmgr_extension_status(PGconn *conn);

repmgr-action-node.c

@@ -96,28 +96,6 @@ do_node_status(void)
 
 	get_node_replication_stats(conn, &node_info);
 
-	/* get system information */
-	{
-		t_conninfo_param_list repl_conninfo;
-		PGconn *replication_conn;
-		t_system_identification sysid = T_SYSTEM_IDENTIFICATION_INITIALIZER;
-		initialize_conninfo_params(&repl_conninfo, false);
-
-		conn_to_param_list(conn, &repl_conninfo);
-
-		param_set(&repl_conninfo, "replication", "1");
-
-		param_set(&repl_conninfo, "user", node_info.repluser);
-
-
-		replication_conn = establish_db_connection_by_params(&repl_conninfo, false);
-		identify_system(replication_conn, &sysid);
-
-		printf("%lu\n", sysid.system_identifier);
-		exit(0);
-
-	}
-
 	key_value_list_set(
 		&node_status,
 		"PostgreSQL version",
@@ -418,6 +396,8 @@ do_node_status(void)
 		/* log_hint(_("execute \"repmgr node check\" for more details")); */
 	}
 
+	key_value_list_free(&node_status);
+	PQfinish(conn);
 }
 
 /*

repmgr-action-standby.c

@@ -1247,8 +1247,12 @@ do_standby_follow(void)
 	PQExpBufferData follow_output;
 	bool    	success;
 
-	log_verbose(LOG_DEBUG, "do_standby_follow()");
+	uint64  	local_system_identifier = UNKNOWN_SYSTEM_IDENTIFIER;
+	t_conninfo_param_list repl_conninfo;
+	PGconn  	*repl_conn = NULL;
+	t_system_identification primary_identification = T_SYSTEM_IDENTIFICATION_INITIALIZER;
 
+	log_verbose(LOG_DEBUG, "do_standby_follow()");
 
 	local_conn = establish_db_connection(config_file_options.conninfo, true);
 
@@ -1263,7 +1267,7 @@ do_standby_follow(void)
 	 * If --wait provided, loop for up `primary_response_timeout`
 	 * seconds before giving up
 	 */
-	// XXX ??? primary_follow_timeout
+
 	for (timer = 0; timer < config_file_options.primary_follow_timeout; timer++)
 	{
 		primary_conn = get_primary_connection_quiet(local_conn,
@@ -1275,20 +1279,60 @@ do_standby_follow(void)
 			break;
 		}
 	}
+	PQfinish(local_conn);
 
 	if (PQstatus(primary_conn) != CONNECTION_OK)
 	{
 		log_error(_("unable to determine primary node"));
-		PQfinish(local_conn);
+
 		exit(ERR_BAD_CONFIG);
 	}
 
-	check_primary_standby_version_match(local_conn, primary_conn);
-
-	PQfinish(local_conn);
-
 	get_node_record(primary_conn, primary_id, &primary_node_record);
 
+	/* check replication connection */
+
+	initialize_conninfo_params(&repl_conninfo, false);
+
+	conn_to_param_list(primary_conn, &repl_conninfo);
+
+	param_set(&repl_conninfo, "replication", "1");
+	param_set(&repl_conninfo, "user", primary_node_record.repluser);
+
+	repl_conn = establish_db_connection_by_params(&repl_conninfo, false);
+	if (PQstatus(repl_conn) != CONNECTION_OK)
+	{
+		log_error(_("unable to establish a replication connection to the primary node"));
+		PQfinish(primary_conn);
+		exit(ERR_BAD_CONFIG);
+	}
+
+	/* check system_identifiers match */
+	local_system_identifier = get_system_identifier(config_file_options.data_directory);
+	success = identify_system(repl_conn, &primary_identification);
+
+	if (success == false)
+	{
+		log_error(_("unable to query the primary node's system identification"));
+		PQfinish(primary_conn);
+		PQfinish(repl_conn);
+		exit(ERR_BAD_CONFIG);
+	}
+
+	if (primary_identification.system_identifier != local_system_identifier)
+	{
+		log_error(_("this node is not part of the primary node's replication cluster"));
+		log_detail(_("this node's system identifier is %lu, primary node's system identifier is %lu"),
+				   local_system_identifier,
+				   primary_identification.system_identifier);
+		PQfinish(primary_conn);
+		PQfinish(repl_conn);
+		exit(ERR_BAD_CONFIG);
+	}
+
+	PQfinish(repl_conn);
+	free_conninfo_params(&repl_conninfo);
+
 	initPQExpBuffer(&follow_output);
 
 	success = do_standby_follow_internal(
@@ -1425,6 +1469,8 @@ do_standby_follow_internal(PGconn *primary_conn, t_node_info *primary_node_recor
 		{
 			original_upstream_node_id = primary_node_record->node_id;
 		}
+
+		free_conninfo_params(&local_node_conninfo);
 	}
 
 	log_info(_("changing node %i's primary to node %i"),

repmgr.h

@@ -34,7 +34,7 @@
 
 #define UNKNOWN_SERVER_VERSION_NUM -1
 #define UNKNOWN_TIMELINE_ID -1
-#define UNKNOWN_SYSTEM_IDENTIFIER -1
+#define UNKNOWN_SYSTEM_IDENTIFIER 0
 
 #define NODE_NOT_FOUND		-1
 #define NO_UPSTREAM_NODE	-1

strutil.c

@@ -191,6 +191,27 @@ key_value_list_get(KeyValueList *item_list, const char *key)
 	return NULL;
 }
 
+
+void
+key_value_list_free(KeyValueList *item_list)
+{
+	KeyValueListCell *cell;
+	KeyValueListCell *next_cell;
+
+	cell = item_list->head;
+
+	while (cell != NULL)
+	{
+		next_cell = cell->next;
+		pfree(cell->key);
+		pfree(cell->value);
+		pfree(cell);
+		cell = next_cell;
+	}
+
+}
+
+
 /*
  * Escape a string for use as a parameter in recovery.conf
  * Caller must free returned value

strutil.h

@@ -82,6 +82,8 @@ key_value_list_set_output_mode(KeyValueList *item_list, const char *key, OutputM
 extern const char *
 key_value_list_get(KeyValueList *item_list, const char *key);
 
+extern void
+key_value_list_free(KeyValueList *item_list);
 
 extern char *
 escape_recovery_conf_value(const char *src);