Association for Computing Machinery
DataCenter Networks (DCNs) are constantly evolving due to various updates such as switch upgrades and VM migrations. Each update must be carefully planned and executed in order to avoid disrupting many of the mission-critical, interactive applications hosted in DCNs. The key challenge arises from the inherent difficulty in synchronizing the changes to many devices, which may result in un-foreseen transient link load spikes or even congestions. The authors present one primitive, zUpdate, to perform congestion-free network updates under asynchronous switch and traffic matrix changes.