We recently ran into an issue where we needed to kill database connections to redshift. To do so, we just wrote the following script. Nothing fancy, but useful.
CREATE OR REPLACE PROCEDURE "admin"."krombopulos_michael" (kill_longer_than_x_hours integer)
AS $$
--Oh boy...
DECLARE
reports RECORD;
BEGIN
FOR reports IN select * from stv_sessions where starttime < DATEADD(HOUR,-1*kill_longer_than_x_hours,GETDATE()) AND user_name <> 'rdsdb' /*system name*/
LOOP
EXECUTE $_$ SELECT pg_terminate_backend( $_$|| reports.process|| $_$ ) $_$;
END LOOP;
END;
$$
LANGUAGE plpgsql