# Energy¶

When a Batsim simulation is run with energy enabled (see Command-line Interface), Batsim outputs energy-specific output files.

You can give a look at this evalys visualization example to see how to use such data.

## Energy consumption trace¶

This file is written as Batsim’s export prefix + _consumed_energy.csv. This is a time series that contains the energy consumption of the platform (as defined as the sum of all the computing hosts of the platform) from time 0 to the current time. It contains the following fields in this order.

• time: The time point at which the measure has been done.
• energy: The amount of energy consumed in joules by the platform from time 0 to time.
This metrics is robust, you can analyze/visualize it without concerns.
• wattmin: The minimum current power consumption of the platform, taking into account the power state into which each host is, and assuming that all hosts have an epsilon load (close to 0 without reaching it).
• epower: The average power consumption of the whole platform since last event to the current one. Use this value with caution as it can be subject to degenerate cases — e.g., when two successive events happen at the same time.
• event_type: The type of the event that occurred at time time.
• s if the event is a job start
• e if the event is a job end
• p if the event is a host power state change

## Power state change trace¶

This file is written as Batsim’s export prefix + _pstate_changes.csv. This is a time series that contains the power state transitions of the hosts over time. It contains the following fields in this order.

• time: The time at which the power state transition occurred.
• machine_id: The Interval set of hosts whose power state has been changed.
• new_pstate: The new power state (an integer) of the involved hosts.

## Agregated machine state trace¶

This file is written as Batsim’s export prefix + _machine_states.csv. This is a time series that contains the number of hosts in each kind of power state over time. Please refer to Energy model for more information about the existing kinds of power states. It contains the following fields in this order.

• time: The time at which the measure has been done.
• nb_sleeping: The number of hosts currently in a sleeping power state.
• nb_switching_on: The number of hosts currently transitioning into a computation power state.
• nb_switching_off: The number of hosts currently transitioning into a sleeping power state.
• nb_idle: The number of hosts currently in a computation power state, but without a job running on them.
• nb_computing: The number of hosts currently in a computation power state, with a job running on them.