8.80. moveset_int(p_wait_seqno integer, p_new_origin integer, p_old_origin integer, p_set_id bigint)

Function Properties

Language: PLPGSQL

Return Type: integer

moveSet(set_id, old_origin, new_origin, wait_seqno) Process MOVE_SET event to request that the origin for set set_id be moved from old_origin to node new_origin

declare
	v_local_node_id		int4;
	v_tab_row			record;
	v_sub_row			record;
	v_sub_node			int4;
	v_sub_last			int4;
	v_sub_next			int4;
	v_last_sync			int8;
begin
	-- ----
	-- Grab the central configuration lock
	-- ----
	lock table sl_config_lock;

	-- ----
	-- Get our local node ID
	-- ----
	v_local_node_id := getLocalNodeId('_schemadoc');

	-- On the new origin, raise an event - ACCEPT_SET
	if v_local_node_id = p_new_origin then
		-- Create a SYNC event as well so that the ACCEPT_SET has
		-- the same snapshot as the last SYNC generated by the new
		-- origin. This snapshot will be used by other nodes to
		-- finalize the setsync status.
		perform createEvent('_schemadoc', 'SYNC', NULL);
		perform createEvent('_schemadoc', 'ACCEPT_SET', 
			p_set_id::text, p_old_origin::text, 
			p_new_origin::text, p_wait_seqno::text);
	end if;

	-- ----
	-- Next we have to reverse the subscription path
	-- ----
	v_sub_last = p_new_origin;
	select sub_provider into v_sub_node
			from sl_subscribe
			where sub_set = p_set_id
			and sub_receiver = p_new_origin;
	if not found then
		raise exception 'Slony-I: subscription path broken in moveSet_int';
	end if;
	while v_sub_node <> p_old_origin loop
		-- ----
		-- Tracing node by node, the old receiver is now in
		-- v_sub_last and the old provider is in v_sub_node.
		-- ----

		-- ----
		-- Get the current provider of this node as next
		-- and change the provider to the previous one in
		-- the reverse chain.
		-- ----
		select sub_provider into v_sub_next
				from sl_subscribe
				where sub_set = p_set_id
					and sub_receiver = v_sub_node
				for update;
		if not found then
			raise exception 'Slony-I: subscription path broken in moveSet_int';
		end if;
		update sl_subscribe
				set sub_provider = v_sub_last
				where sub_set = p_set_id
					and sub_receiver = v_sub_node
					and sub_receiver <> v_sub_last;

		v_sub_last = v_sub_node;
		v_sub_node = v_sub_next;
	end loop;

	-- ----
	-- This includes creating a subscription for the old origin
	-- ----
	insert into sl_subscribe
			(sub_set, sub_provider, sub_receiver,
			sub_forward, sub_active)
			values (p_set_id, v_sub_last, p_old_origin, true, true);
	if v_local_node_id = p_old_origin then
		select coalesce(max(ev_seqno), 0) into v_last_sync 
				from sl_event
				where ev_origin = p_new_origin
					and ev_type = 'SYNC';
		if v_last_sync > 0 then
			insert into sl_setsync
					(ssy_setid, ssy_origin, ssy_seqno,
					ssy_snapshot, ssy_action_list)
					select p_set_id, p_new_origin, v_last_sync,
					ev_snapshot, NULL
					from sl_event
					where ev_origin = p_new_origin
						and ev_seqno = v_last_sync;
		else
			insert into sl_setsync
					(ssy_setid, ssy_origin, ssy_seqno,
					ssy_snapshot, ssy_action_list)
					values (p_set_id, p_new_origin, '0',
					'1:1:', NULL);
		end if;
	end if;

	-- ----
	-- Now change the ownership of the set.
	-- ----
	update sl_set
			set set_origin = p_new_origin
			where set_id = p_set_id;

	-- ----
	-- On the new origin, delete the obsolete setsync information
	-- and the subscription.
	-- ----
	if v_local_node_id = p_new_origin then
		delete from sl_setsync
				where ssy_setid = p_set_id;
	else
		if v_local_node_id <> p_old_origin then
			--
			-- On every other node, change the setsync so that it will
			-- pick up from the new origins last known sync.
			--
			delete from sl_setsync
					where ssy_setid = p_set_id;
			select coalesce(max(ev_seqno), 0) into v_last_sync
					from sl_event
					where ev_origin = p_new_origin
						and ev_type = 'SYNC';
			if v_last_sync > 0 then
				insert into sl_setsync
						(ssy_setid, ssy_origin, ssy_seqno,
						ssy_snapshot, ssy_action_list)
						select p_set_id, p_new_origin, v_last_sync,
						ev_snapshot, NULL
						from sl_event
						where ev_origin = p_new_origin
							and ev_seqno = v_last_sync;
			else
				insert into sl_setsync
						(ssy_setid, ssy_origin, ssy_seqno,
						ssy_snapshot, ssy_action_list)
						values (p_set_id, p_new_origin,
						'0', '1:1:', NULL);
			end if;
		end if;
	end if;
	delete from sl_subscribe
			where sub_set = p_set_id
			and sub_receiver = p_new_origin;

	-- Regenerate sl_listen since we revised the subscriptions
	perform RebuildListenEntries();

	-- Run addPartialLogIndices() to try to add indices to unused sl_log_? table
	perform addPartialLogIndices();

	-- ----
	-- If we are the new or old origin, we have to
	-- adjust the log and deny access trigger configuration.
	-- ----
	if v_local_node_id = p_old_origin or v_local_node_id = p_new_origin then
		for v_tab_row in select tab_id from sl_table
				where tab_set = p_set_id
				order by tab_id
		loop
			perform alterTableConfigureTriggers(v_tab_row.tab_id);
		end loop;
	end if;

	return p_set_id;
end;