I started web-proxy but I want one site (X.X.X.X) don`t cashed
Go to ‘ip [web-]proxy cache’, add desired address to cache list and specify ‘action=deny’, to ensure that content from the particular address is not cached.
Please exemple 
And one more question I have 2 ISP and proxy work only with ISP1 (traffic from proxy-to is through ISP1)
How to add when ISP1 is down traffic to redirect through ISP2