Christopher B. Browne's Home Page

8.81. moveset(integer, integer)

Function Properties

moveSet(set_id, new_origin) Generate MOVE_SET event to request that the origin for set set_id be moved to node new_origin
    	p_set_id			alias for $1;
    	p_new_origin		alias for $2;
    	v_local_node_id		int4;
    	v_set_row			record;
    	v_sub_row			record;
    	v_sync_seqno		int8;
    	v_lv_row			record;
    	-- ----
    	-- 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',
    	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);

Contact me at