How did Sonny know Paulie set up Vito?

Sonny did not waste time ordering Clemenza to wack Paulie. Paulie sticks his head in the room during a meeting .... still pretending he was sick? Sonny suggests some whiskey to help. When Paulie leaves .... Sonny gives the order. How did Sonny know this so quickly and also how could he tolerate him even being under same roof after selling out the Don? I guess he could hold his temper. It seems like Sonny would have beat him to a pulp .... then and there. Sonny stepped to Clemenza just for saying "word of the street" rumor!