Measurement Protocol
Each server under test was assigned to a specific outlet on the Raritan PDU. The PDU was plugged into and powered through the watt meter, which had a USB connection to the laptop that ran the WattsUP-Pro realtime logging software. For each test run, the meter logging software was set to take the total (global) power draw (including the PDU's draw), voltage, current, etc. samples every 15 seconds.
In parallel a shell script was run to retrieve the information available (power, current, voltage, etc.) from each individual outlet through SNMP. The script was configured to retrieve the information from each outlet in round robin fashion every 15 seconds so that an individual outlet would have its information sampled every 45 seconds. Additionally, the PDU's information (power, current, voltage) is collected along with each outlet's information to correlate with the external watt meter's readings. PDU overhead is included in the measurement.
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