Recently, MapReduce has been a key and popular technology for tackling data-intensive applications. But its two master servers in current MapReduce implementations have a single-failure problem, which may interrupt MapReduce operations and filesystem services. In this paper, we propose a hybrid takeover scheme, called the Proactive and Adaptive Redundant System (PAReS for short), which employs three service-quality improvement mechanisms, including a proactive synchronization and replication method, a mutual monitoring algorithm, and an adaptive warm-up mechanism, to mitigate the above problems. The extensive experiments show that PAReS enhances service quality at acceptable energy consumption level and synchronization cost as compared with four state-of- the-art schemes.