It is well-known that without strict network bandwidth guarantees, application performance in multi-tenant cloud environments is unpredictable. While recently proposed systems support explicit bandwidth reservation mechanisms, they require the resource schedules to be announced ahead of time. We argue that this is not practical in today’s cloud environments, where application demands are inherently unpredictable, e.g., due to stragglers. We in this paper present KRAKEN, a system that allows tenants to dynamically request and update minimum resource guarantees for both network bandwidth and compute resources at runtime. Unlike previous work, Kraken does not require prior knowledge about the resource needs of the tenants’ applications but allows tenant to modify their reservation at runtime. Kraken achieves this through an online resource reservation scheme, and by optimally embedding and reconfiguring virtual networks.

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