The boundedness of the maximal operator on the upper half-plane pi+ is established. Here pi+ is equipped with a positive Borel measure d omega(y)dx satisfying the doubling property omega ((0, 2t)) <= C omega ((0, t)). This result is connected to the Carleson embedding theorem, which we use to characterize the boundedness and compactness of the Volterra type integral operators on the Bergman spaces Ap omega(pi+).