Alyssa Maclean Cobb , the daughter of Susanna Dodds Cobb and Jonathan Cobb of Tarrytown , N.Y. , is to be married today to Dmitri Vladimirovich Konon , the son of Inna and Walter Konon of Waccabuc , N.Y . The Very Rev . Andrei Sommer , a Russian Orthodox priest , is to perform the ceremony at the Cathedral of Our Lady of the Sign in New York .