  Datacenter networks routinely support the data transfers of distributed
computing frameworks in the form of coflows, i.e., sets of concurrent flows
related to a common task. The vast majority of the literature has focused on
the problem of scheduling coflows for completion time minimization, i.e., to
maximize the average rate at which coflows are dispatched in the network
fabric. Modern applications, though, may generate coflows dedicated to online
services and mission-critical computing tasks which have to comply with
specific completion deadlines. In this paper, we introduce $\mathtt{DCoflow}$,
a lightweight deadline-aware scheduler for time-critical coflows in datacenter
networks. The algorithm combines an online joint admission control and
scheduling logic and returns a $\sigma$-order schedule which maximizes the
number of coflows that attain their deadlines. Extensive numerical results
demonstrate that the proposed solution outperforms existing ones.
