In 2007, the Green500 list was introduced, which compares supercomputers by performance-per-watt. Since supercomputers consist of thousands of nodes, energy-saving is a growing demand. Compute clusters are often managed by a so-called Resource Management Systems (RMS), which have load information about the whole system. For clusters with changing compute demands, this can be used to switch on/off nodes according to the current load situation and save energy this way. Here, the authors present energy-saving techniques that work on the management level and measurements that show that speed scaling is not a good means for energy saving. Further, they give an overview of some important standards and specifications related to energy saving, like ACPI and IPMI. Finally, the authors present their energy-saving daemon called CHERUB. Due to its modular design, it can operate with different Resource Management Systems. Their experimental results show that CHERUB’s scheduling algorithm works well, i.e. it will save energy, if possible, and avoids state flapping.
Information and resource management systems for Internet of Things: Energy management, communication protocols and future applications
