We introduce a novel decentralized monitoring algorithm for mobile ad-hoc networks. This algorithm is a combination of gossip-based and tree-based approaches. Its main feature is on multi root nodes selection which provides an opportunity to obtain more accurate results as it maximizes the coverage of the network. Our proposal relies on a thorough defined algorithm and its efficient and effective implementation. The algorithm is divided in two main parts that are its query procedure and its disseminate procedure. To assess different parameters such as accuracy and convergence time, we conducted experiments with an in-house emulated test bed based on Docker and NS3. To show the effectiveness and scalability of our proposal, we conduct intensive emulations that demonstrate very promising results regarding the gain of accuracy