Cloud‐Toolkit

jPowerMonitor cannot read out the power consumption, e.g. of the CPU or the entire system, itself, but is dependent on a measurement backend with a REST or CSV interface.

This is not a problem on physical computers, as tools such as LibreHardwareMonitor are available under Windows or Running Average Power Limit(RAPL)) under Linux. The Cloud Toolkit extension for jPowerMonitor aims to improve the transparency of energy consumption in the cloud.

CPU power consumption estimation

Based on internally determined CPU utilization data, the jPowerMonitor Cloud-Toolkit provides a relatively accurate estimate of CPU power consumption, even in virtualized environments. The methodology follows the principles of Cloud Carbon Footprint.

In the jPowerMonitor configuration, an additional measurement method “est” (short for “estimation”, alongside “lhm” for LibreHardwareMonitor and “csv” for the generic CSV interface) has now been introduced (from version >= 1.2.0).

The “est” measurement method only requires two additional input parameters:

• cpuMinWatts: minimum power consumption of the CPU (“idle” consumption)
• cpuMaxWatts: maximum power consumption of the CPU (under full load)

On local systems, both values can be determined in advance using LibreHardwareMonitor or another measurement tool. If necessary, the CPU manufacturer's specifications from the data sheet can be used instead, e.g. “Idle” consumption and TDP (Thermal Design Power).

If it is possible to obtain real “live” measurement data, this is of course always more accurate and therefore preferable.

There are various tables on the internet for cloud platforms, from which the values for different VM instance types, for example, can be read (see e.g. cloud-carbon-coefficients/data or re-cinq). The current average values for AWS (Amazon Web Services) EC2 are already preconfigured in the jpowermonitor.yaml template. For a CO2eq consumption that is automatically and correctly converted by jPowerMonitor from the energy estimate data, the electricity mix (“carbonDioxideEmissionFactor”, see 9) at the location of the cloud data center must also be specified. A detailed description of the configuration can be found in the README.md file.