8.79. moveset(p_new_origin integer, p_set_id integer)

Function Properties

Language: PLPGSQL

Return Type: bigint

moveSet(set_id, new_origin) Generate MOVE_SET event to request that the origin for set set_id be moved to node new_origin

declare
	v_local_node_id		int4;
	v_set_row			record;
	v_sub_row			record;
	v_sync_seqno		int8;
	v_lv_row			record;
begin
	-- ----
	-- Grab the central configuration lock
	-- ----
	lock table sl_config_lock;

	-- ----
	-- Check that the set is locked and that this locking
	-- happened long enough ago.
	-- ----
	v_local_node_id := getLocalNodeId('_schemadoc');
	select * into v_set_row from sl_set
			where set_id = p_set_id
			for update;
	if not found then
		raise exception 'Slony-I: set % not found', p_set_id;
	end if;
	if v_set_row.set_origin <> v_local_node_id then
		raise exception 'Slony-I: set % does not originate on local node',
				p_set_id;
	end if;
	if v_set_row.set_locked isnull then
		raise exception 'Slony-I: set % is not locked', p_set_id;
	end if;
	if v_set_row.set_locked > "pg_catalog".txid_snapshot_xmin("pg_catalog".txid_current_snapshot()) then
		raise exception 'Slony-I: cannot move set % yet, transactions < % are still in progress',
				p_set_id, v_set_row.set_locked;
	end if;

	-- ----
	-- Unlock the set
	-- ----
	perform unlockSet(p_set_id);

	-- ----
	-- Check that the new_origin is an active subscriber of the set
	-- ----
	select * into v_sub_row from sl_subscribe
			where sub_set = p_set_id
			and sub_receiver = p_new_origin;
	if not found then
		raise exception 'Slony-I: set % is not subscribed by node %',
				p_set_id, p_new_origin;
	end if;
	if not v_sub_row.sub_active then
		raise exception 'Slony-I: subsctiption of node % for set % is inactive',
				p_new_origin, p_set_id;
	end if;

	-- ----
	-- Reconfigure everything
	-- ----
	perform moveSet_int(p_set_id, v_local_node_id,
			p_new_origin, 0);

	perform RebuildListenEntries();

	-- ----
	-- At this time we hold access exclusive locks for every table
	-- in the set. But we did move the set to the new origin, so the
	-- createEvent() we are doing now will not record the sequences.
	-- ----
	v_sync_seqno := createEvent('_schemadoc', 'SYNC');
	insert into sl_seqlog 
			(seql_seqid, seql_origin, seql_ev_seqno, seql_last_value)
			select seq_id, v_local_node_id, v_sync_seqno, seq_last_value
			from sl_seqlastvalue
			where seq_set = p_set_id;
					
	-- ----
	-- Finally we generate the real event
	-- ----
	return createEvent('_schemadoc', 'MOVE_SET', 
			p_set_id::text, v_local_node_id::text, p_new_origin::text);
end;