Research and development of autonomics have come a long way, and we are - lighted to present the proceedings of the 4th IEEE International Workshop on Modeling Autonomic Communications Environments (MACE 2009). As in the last three years, this workshop was held as part of Manweek, the International Week on Management of Networks and Services, which took place in the cult- ally rich city of Venice in Italy. Manweek is now an umbrella of ?ve workshops and conferences focusing on di?erent aspects of network and service mana- ment, including MACE, distributed operations and management (DSOM), -...