(Article begins on next page) A Catalogue of Green Architectural Tactics for the

Abstract—Energy efficiency is a primary concern for the ICT sector. In particular, the widespread adoption of cloud computing technologies has drawn attention to the massive energy consump-tion of data centers. Although hardware constantly improves with respect to energy efficiency, this should also be a main concern for software. In previous work we analyzed the literature and elicited a set of techniques for addressing energy efficiency in cloud-based software architectures. In this work we codified these techniques in the form of Green Architectural Tactics. These tactics will help architects extend their design reasoning towards energy efficiency and to apply reusable solutions for greener software. I