Disable any configuration settings not compatible with PostgreSQL 9.3

And emit a warning while we're at it.

configfile.c

@@ -260,6 +260,7 @@ _parse_config(t_configuration_options *options, ItemList *error_list, ItemList *
 	options->tablespace_mapping.head = NULL;
 	options->tablespace_mapping.tail = NULL;
 	memset(options->recovery_min_apply_delay, 0, sizeof(options->recovery_min_apply_delay));
+	options->recovery_min_apply_delay_provided = false;
 	options->use_primary_conninfo_password = false;
 
 	/*-----------------
@@ -435,7 +436,10 @@ _parse_config(t_configuration_options *options, ItemList *error_list, ItemList *
 		else if (strcmp(name, "restore_command") == 0)
 			strncpy(options->restore_command, value, MAXLEN);
 		else if (strcmp(name, "recovery_min_apply_delay") == 0)
+		{
 			parse_time_unit_parameter(name, value, options->recovery_min_apply_delay, error_list);
+			options->recovery_min_apply_delay_provided = true;
+		}
 		else if (strcmp(name, "use_primary_conninfo_password") == 0)
 			options->use_primary_conninfo_password = parse_bool(value, name, error_list);
 

configfile.h

@@ -88,6 +88,7 @@ typedef struct
 	char		restore_command[MAXLEN];
 	TablespaceList tablespace_mapping;
 	char		recovery_min_apply_delay[MAXLEN];
+	bool		recovery_min_apply_delay_provided;
 	bool		use_primary_conninfo_password;
 
 	/* node check settings */
@@ -152,7 +153,7 @@ typedef struct
 		/* log settings */ \
 		"", "", "", DEFAULT_LOG_STATUS_INTERVAL,	\
 		/* standby action settings */ \
-		false, "", "", { NULL, NULL }, "", false, \
+		false, "", "", { NULL, NULL }, "", false, false, \
 		/* node check settings */ \
 		DEFAULT_ARCHIVE_READY_WARNING, DEFAULT_ARCHIVE_READY_CRITICAL, \
 		DEFAULT_REPLICATION_LAG_WARNING, DEFAULT_REPLICATION_LAG_CRITICAL, \

repmgr-action-node.c

@@ -1598,6 +1598,7 @@ do_node_rejoin(void)
 	t_node_info primary_node_record = T_NODE_INFO_INITIALIZER;
 
 	bool		success = true;
+	int			server_version_num = UNKNOWN_SERVER_VERSION_NUM;
 
 	/* check node is not actually running */
 
@@ -1646,6 +1647,12 @@ do_node_rejoin(void)
 	/* check provided upstream connection */
 	upstream_conn = establish_db_connection_by_params(&source_conninfo, true);
 
+	/* sanity-checks for 9.3 */
+	server_version_num = get_server_version(upstream_conn, NULL);
+
+	if (server_version_num < 90400)
+		check_93_config();
+
 	/* establish_db_connection(runtime_options.upstream_conninfo, true); */
 
 	if (get_primary_node_record(upstream_conn, &primary_node_record) == false)

repmgr-action-standby.c

@@ -81,7 +81,6 @@ static bool check_upstream_config(PGconn *conn, int server_version_num, t_node_i
 static void check_primary_standby_version_match(PGconn *conn, PGconn *primary_conn);
 static void check_recovery_type(PGconn *conn);
 
-
 static void initialise_direct_clone(t_node_info *node_record);
 static int	run_basebackup(t_node_info *node_record);
 static int	run_file_backup(t_node_info *node_record);
@@ -1544,6 +1543,7 @@ do_standby_follow(void)
 	RecordStatus record_status = RECORD_NOT_FOUND;
 
 	int			timer = 0;
+	int			server_version_num = UNKNOWN_SERVER_VERSION_NUM;
 
 	PQExpBufferData follow_output;
 	bool		success = false;
@@ -1562,6 +1562,12 @@ do_standby_follow(void)
 	/* check this is a standby */
 	check_recovery_type(local_conn);
 
+	/* sanity-checks for 9.3 */
+	server_version_num = get_server_version(local_conn, NULL);
+
+	if (server_version_num < 90400)
+		check_93_config();
+
 	if (runtime_options.upstream_node_id != NO_UPSTREAM_NODE)
 	{
 		/* check not self! */
@@ -1682,13 +1688,11 @@ do_standby_follow(void)
 
 	initPQExpBuffer(&follow_output);
 
-	success = do_standby_follow_internal(
+	success = do_standby_follow_internal(primary_conn,
-										 primary_conn,
 										 &primary_node_record,
 										 &follow_output);
 
-	create_event_notification(
+	create_event_notification(primary_conn,
-							  primary_conn,
 							  &config_file_options,
 							  config_file_options.node_id,
 							  "standby_follow",
@@ -1718,6 +1722,9 @@ do_standby_follow(void)
 /*
  * Perform the actuall "follow" operation; this is executed by
  * "node rejoin" too.
+ *
+ * For PostgreSQL 9.3, ensure check_93_config() was called before calling
+ * this function.
  */
 bool
 do_standby_follow_internal(PGconn *primary_conn, t_node_info *primary_node_record, PQExpBufferData *output)
@@ -3103,6 +3110,10 @@ check_source_server()
 		}
 	}
 
+	/* disable configuration file options incompatible with 9.3 */
+	if (source_server_version_num < 90400)
+		check_93_config();
+
 	check_upstream_config(source_conn, source_server_version_num, &node_record, true);
 }
 
@@ -3203,6 +3214,8 @@ check_source_server_via_barman()
  * Perform sanity check on upstream server configuration before starting cloning
  * process
  *
+ * For PostreSQL 9.3, ensure check_93_config() is called before calling this.
+ *
  * TODO:
  *  - check user is qualified to perform base backup
  */
@@ -3253,6 +3266,12 @@ check_upstream_config(PGconn *conn, int server_version_num, t_node_info *node_in
 		xlog_stream = false;
 
 	/* Check that WAL level is set correctly */
+	if (server_version_num < 90400)
+	{
+		i = guc_set(conn, "wal_level", "=", "hot_standby");
+		wal_error_message = _("parameter \"wal_level\" must be set to \"hot_standby\"");
+	}
+	else
 	{
 		char	   *levels_pre96[] = {
 			"hot_standby",
@@ -3277,12 +3296,12 @@ check_upstream_config(PGconn *conn, int server_version_num, t_node_info *node_in
 		if (server_version_num < 90600)
 		{
 			levels = (char **) levels_pre96;
-			wal_error_message = _("parameter 'wal_level' must be set to 'hot_standby' or 'logical'");
+			wal_error_message = _("parameter \"wal_level\" must be set to \"hot_standby\" or \"logical\"");
 		}
 		else
 		{
 			levels = (char **) levels_96plus;
-			wal_error_message = _("parameter 'wal_level' must be set to 'replica' or 'logical'");
+			wal_error_message = _("parameter \"wal_level\" must be set to \"replica\" or \"logical\"");
 		}
 
 		do
@@ -4838,7 +4857,7 @@ create_recovery_file(t_node_info *node_record, t_conninfo_param_list *recovery_c
 	log_debug("recovery.conf: %s", line);
 
 	/* recovery_min_apply_delay = ... (optional) */
-	if (*config_file_options.recovery_min_apply_delay)
+	if (config_file_options.recovery_min_apply_delay_provided == true)
 	{
 		maxlen_snprintf(line, "recovery_min_apply_delay = %s\n",
 						config_file_options.recovery_min_apply_delay);

repmgr-client-global.h

@@ -198,6 +198,7 @@ extern t_node_info target_node_info;
 
 
 extern int	check_server_version(PGconn *conn, char *server_type, bool exit_on_error, char *server_version_string);
+extern void check_93_config(void);
 extern bool create_repmgr_extension(PGconn *conn);
 extern int	test_ssh_connection(char *host, char *remote_user);
 extern bool local_command(const char *command, PQExpBufferData *outputbuf);

repmgr-client.c

@@ -1998,6 +1998,30 @@ check_server_version(PGconn *conn, char *server_type, bool exit_on_error, char *
 }
 
 
+
+/*
+ * check_93_config()
+ *
+ * Disable options not compatible with PostgreSQL 9.3
+ */
+void
+check_93_config(void)
+{
+	if (config_file_options.recovery_min_apply_delay_provided == true)
+	{
+		config_file_options.recovery_min_apply_delay_provided = false;
+		log_warning(_("configuration file option \"recovery_min_apply_delay\" not compatible with PostgreSQL 9.3, ignoring"));
+	}
+
+	if (config_file_options.use_replication_slots == true)
+	{
+		config_file_options.use_replication_slots = false;
+		log_warning(_("configuration file option \"use_replication_slots\" not compatible with PostgreSQL 9.3, ignoring"));
+		log_hint(_("replication slots are available from PostgreSQL 9.4"));
+	}
+}
+
+
 int
 test_ssh_connection(char *host, char *remote_user)
 {