Abstract: The sizing of virtual machines is optimized based on projected performance metrics. All virtual machine configuration resources are normalized by a processing device. The normalized resources for the virtual machine configurations are then stored in a catalogue. An application is then profiled to obtain resource demand estimates for each virtual machine configuration and a base performance is calculated for the application. The base performance is used to predict performance estimates on all virtual machine configurations in the catalogue. Accordingly, a virtual machine configuration having a lowest response time is selected.

Abstract: A method for hierarchical occupancy based congestion management includes receiving, by a computing device, a plurality of data flows, each of the plurality of data flows is received from a source and includes a plurality of data packets and storing the plurality of data packets in a buffer including multiple storage units. The method includes determining if the buffer is congested, responsive to determining the buffer is congested randomly selecting at least two occupied units of the buffer and identifying a source of each of the data packets stored in the occupied units of the buffer and generating a congestion notification message. The method also includes comparing a selection criterion associated with each identified source to determine which identified source has a higher selection criterion and sending the congestion notification message to the identified source with the higher selection criterion.

Abstract: A system for hierarchical occupancy based congestion management includes a buffer embodied in a computer readable storage medium including a plurality of buffer units for storing packets of a data flow received from sources. The system includes a buffer manager that stores information about the packets stored in the buffer, including a selection criterion associated with each of the plurality of sources and a congestion estimator that monitors a congestion level in the buffer. The system also includes a occupancy sampler that randomly selects at least two occupied buffer units from the plurality of buffer units and identifies the source of the packet stored in each of the occupied buffer units and a congestion notification message generator that generates a congestion notification message; wherein if the congestion level in the buffer exceeds a threshold value the congestion notification message is sent to the identified source with a higher selection criteria.