  Machine learning techniques are finding many applications in computer
systems, including many tasks that require decision making: network
optimization, quality of service assurance, and security. We believe machine
learning systems are here to stay, and to materialize on their potential we
advocate a fresh look at various key issues that need further attention,
including security as a requirement and system complexity, and how machine
learning systems affect them. We also discuss reproducibility as a key
requirement for sustainable machine learning systems, and leads to pursuing it.
