I. Introduction
Network monitoring and measurement have been critical to various network management tasks, such as traffic engineering [2], [3], accounting [4], [5], [6], load balancing [7], [8], [9], flow scheduling [10], [11], and anomaly detection [12], [13], [14]. These tasks often require timely and accurate estimates of the network flow metrics, e.g., heavy hitters [15], [16], [17], [18], flow size distribution [19], or heavy changes [20], [21]. In response, recent efforts have demonstrated that sketching algorithms (sketches) can estimate these metrics with high fidelity at a high throughput using only small amounts of resources [22], [23].