EARGM is a cluster wide component offering cluster energy monitoring and capping. EARGM can work in two modes: manual and automatic. When running in manual mode, EARGM monitors the total energy consumption, evaluates the percentage of energy consumption over the energy limit set by the admin and reports the cluster status to the DB. When running in automatic mode, apart from evaluating the energy consumption percentage it sends the evaluation to computing nodes. EARDs passes these messages to EARL which re-applies the energy policy with the new settings.
Apart from sending messages and reporting the energy consumption to the DB, EARGM offers additional features to notify the energy consumption: automatic execution of commands is supported and mails can also automatically be sent. Both the command to be executed or the mail address can be defined in the ear.conf
, where it can also be specified the energy limits, the monitoring period, etc.
EARGM uses periodic aggregated power metrics to efficiently compute the cluster energy consumption. Aggregated metrics are computed by EARDBD based on power metrics reported by EARD, the per-node daemon.
Note: if you have multiple EARGMs running, only 1 should be used for Energy management. To turn off energy management for a certain EARGM simply set its energy value to 0.
EARGM also includes an optional power capping system. Power capping can work in two different ways:
Furthermore, when using fine grained power cap control it is possible to have multiple EARGMs, each controlling a part of the cluster, with (or without) meta-EARGMs redistributing the power allocation of each EARGM depending on the current needs of each part of the cluster. If no meta-EARGMs are specified, the power value each EARGM has will be static.
Meta-EARGMs are NOT compatible with the unlimited cluster powercap mode.
The EAR Global Manager uses the $(EAR_ETC)/ear/ear.conf
file to be configured. It can be dynamically configured by reloading the service.
Please visit the EAR configuration file page for more information about the options of EARGM and other components.
Additonally, 2 EARGMs can be used in the same host by declaring the environment variable EARGMID to specify which EARGM configuration each should use. If said variable is not declared, all EARGMs in the same host will read the first entry.
To execute this component, these systemctl
command examples are provided:
sudo systemctl start eargmd
to start the EARGM service.sudo systemctl stop eargmd
to stop the EARGM service.sudo systemctl reload eargmd
to force reloading the configuration of the EARGM service.