  This paper details a data structure for managing and scheduling requests for
computing resources of clusters and virtualised infrastructure such as private
clouds. The data structure uses a red-black tree whose nodes represent the
start times and/or completion times of requests. The tree is enhanced by a
double-linked list that facilitates the iteration of nodes once the start time
of a request is determined by using the tree. We describe the data structure
main features, provide an example of use, and discuss experiments that
demonstrate that the average complexity of two operations are often below 10%
of their respective theoretical worst cases.
