EAR plugins

Some of the core of EAR functionality can be dynamically loaded through a plug-in mechanism, making EAR more extensible and dynamic than previous versions since it is not needed to reinstall the system to add, for instance, a new policy or a new power model. It is only needed to copy the file in the $EAR_INSTALL_PATH/lib/plugins folder and restart some components. The following table lists the current EAR functionalities designed with a plug-in mechanism:

Plug-in	Description
Power model	Energy models used by energy policies.
Power policies	Energy policies themselves.
Energy readings	Node energy readings.
Tracing	Execution traces.
Report	Data reporting.
Powercap	Powercap management.

Considerations

• Plug-in paths is set by default to $EAR_INSTALL_PATH/lib/plugins.
• Default power model library is specified in ear.conf (energy_model option). By default EAR includes a basic_model.so and avx512_model.so plug-ins.
• The node energy readings library is specified at ear.conf in the energy_plugin option for each tag. Several plug-ins are included: energy_nm.so (uses Intel NodeManager IPMI commands), energy_rapl.so (uses a node energy estimation based on DRAM and PACKAGE energy provided by RAPL), energy_sd650.so (uses the high frequency IPMI hardware included in Lenovo SD650 systems) and the energy_inm_power_freeipmi.so, which uses the Intel Node Manager power reading commands and requires the freeipmi library.
• Power policies included in EAR are: monitoring.so, min_energy.so, min_time.so, min_energy_no_models.so and min_time_no_models.so. The list of policies installed is automatically detected by the EAR plug-in. However, only policies included in ear.conf can be used.
• The tracing is an optional functionality. It is included to provide additional information or to generate runtime information.
• Report plug-ins include different options to report EAR data from the different components. By default it is included the eard, eardbd, csv_ts, mysql/psql (depending on the installation). Plug-ins to be loaded by default can be specified on the ear.conf. For more information, check the report section

Note SLURM Plugin does not fit in this philosophy, it is a core component of EAR and can not be replaced by any third party development.