InfluxDB Exporter » Dale Ghent

InfluxDB Exporter is a NINA plugin that transmits periodic hardware, guiding, and image metrics to an InfluxDB time-series database. From there, the metrics may be graphed using tools such as Grafana or InfluxDB’s own built-in graphing features. A time-series database is optimized to collect and store temporally-oriented data. This data may be archived indefinitely or ephemerally, depending on the desired use and purpose.

Metrics are provided on the basis of class of equipment and the statistics of each saved image. For equipment, metrics for each class are sent each time N.I.N.A. polls the hardware for its status, which is every two seconds by default. Refer to Options > General > Advanced settings > Device polling interval. This also means that only connected hardware will have statistics transmitted. Certain metrics will also have tags associated with them which can be used in a variety of ways to select and present the data. Tags are kept to a minimum in order to manage cardinality and may be turned on and off on the plugin’s Options screen.

No sequencer instructions are required to operate this plugin as it will always transmit metrics as long as NINA is running and is connected to any relevant equipment. Naturally, a working InfluxDB API key, bucket, and organization are required as well.

Example use of metrics

My system’s Grafana-based dashboard can be found here. It displays live and historic stats from my PlaneWave CDK14-based imaging system. The metrics behind these graphs and displays are sent from NINA via InfluxDB Exporter to an InfluxDB instance. A separate Grafana instance uses that InfluxDB system as a data source to produce the graphs. A few other things are involved, such as MQTT and web API queries for stuff like the Last Target panel. Influx’s Telegraf is used to gather stats on and to monitor the setup’s APC UPS.

Requirements

NINA 3.2 (nightly) and later. The requirement for 3.2 stems from this plugin using the same dependencies that other parts of NINA uses, but different versions of them. This can lead to a conflict that prevents the plugin from loading. NINA 3.2 solves this issue by loading each plugin into its own assembly context.
InfluxDB 2.x or later.
Optional but suggested: Grafana

For small deployments, InfluxDB and Grafana are both available as Docker containers. Refer to their respective sites for installation and administration documentation.

FAQ

What is the scope of this plugin?

For now, InfluxDB Exporter’s mission in life is simple: to get equipment and image metrics from N.I.N.A. into one of the most popular TSDBs available. Statistics concerning the underlying operating system or external systems not directly managed by N.I.N.A. via ASCOM/Alpaca or its own “native” drivers is outside the scope. Collecting metrics from external software or systems should be done using other metric collection systems such as Telegraf and Prometheus.

Will you add an option to convert metrics that contain metric units to imperial?

InfluxDB Exporter should be thought of as a data relay system, not as a presentation system. Conversions to other units should be done with whichever presentation system you choose to use. Grafana, for example, has the concept of data transforms which you can use to transform data from metric units to imperial. Such conversions would be inappropriate to do at InfluxDB Export’s level.

Does this plugin install InfluxDB for me?

No, this plugin does not provide InfluxDB or any higher-level presentation and analysis software; only itself. There are various resources online for running InfluxDB and Grafana on a Raspberry Pi, Docker container, or any Linux/UNIX system. For cloud-based solutions, you can consider InfluxDB Cloud and Grafana Cloud.

List of metrics

The following tables catalog all metrics and tags that are transmitted.

Global tags, applied to all metrics

profile_name: The name of the active N.I.N.A. profile
host_name: The name of the computer

Astrometric

Metric	Definition	Type
`astro_moon_altitude`	Moon’s altitude in degrees	double
`astro_sun_altitude`	Sun’s altitude in degrees	double

Camera

Additional tags:

camera_name: The name of the connected canera device

Metric	Definition	Type
`camera_sensor_temperature`	Sensor temperature in °C	double
`camera_cooler_power`	Cooler power level in percent	double
`camera_battery_level`	Camera battery charge level	integer

Focuser

Additional tags:

focuser_name: The name of the connected focuser device

Metric	Definition	Type
`focuser_temperature`	Focuser’s temperature sensor in °C	double
`focuser_position`	Step number/position reported by focuser	integer

Guider

Additional tags:

guider_name: The name of the connected guiding device

Metric	Definition	Type
`guider_rms_ra_arcsec`	RA RMS in arcseconds	double
`guider_rms_dec_arcsec`	Declination RMS in arcseconds	double
`guider_rms_arcsec`	Comined RMS in arcseconds	double
`guider_rms_ra_pixel`	RA RMS in pixels	double
`guider_rms_dec_pixel`	Declination RMS in pixels	double
`guider_rms_pixel`	Combined RMS in pixels	double
`guider_rms_peak_ra_arcsec`	RA peak RMS in arcseconds	double
`guider_rms_peak_dec_arcsec`	Declination peak RMS in arcseconds	double
`guider_rms_peak_arcsec`	Combined peak RMS in arcseconds	double
`guider_rms_peak_ra_pixel`	RA peak RMS in arcseconds	double
`guider_rms_peak_dec_pixel`	Declination peak RMS in pixels	double
`guider_rms_peak_pixel`	Combined peak RMS in pixels	double

Mount

Additional tags:

mount_name: The name of the connected mount device

Metric	Definition	Type
`mount_altitude`	Altitude in degrees	double
`mount_azimuth`	Azimuth in degrees	double

Rotator

Additional tags:

rotator_name: The name of the connected rotator device

Metric	Definition	Type
`rotator_mechanical_angle`	Mecanical angle in degrees	double
`rotator_angle`	Sky angle in degrees	double

Switches

Additional tags:

guider_name: The name of the connected guiding device

Metric	Definition	Type
`switch_ro_sw<ID>`	Value of gauge (read-only switch) identified by the appended numeric identifier	double

Each swtich metric is tagged with the human-readable name associated with the switch’s ID.

Weather

Additional tags:

wx_device_name: The name of the connected weather/observing conditions device

Metric	Definition	Type
`wx_cloud_cover`	Cloud cover in percent	double
`wx_dewpoint`	Dewpoint in °C	double
`wx_humidity`	Relative humidity in percent	double
`wx_pressure`	Air pressure in hectopascals	double
`wx_rain_rate`	Rain rate in mm/hour	double
`wx_sky_brightness`	Sky brightness in lux	double
`wx_sky_quality`	Sky quality in magnitudes/arcsecond<sup>2</sup>	double
`wx_sky_temperature`	Sky temperature in °C	double
`wx_star_fwhm`	Measured star FWHM	double
`wx_temperature`	Ambient air temperature in °C	double
`wx_wind_direction`	Wind direction in azimuthal degrees	double
`wx_wind_gust`	Wind gust speed in meters/second	double
`wx_wind_speed`	Wind speed in meters/second	double

Image statistics

Statistics are produced only for images of type LIGHT. Calibration frames and snapshots are not processed. Statistics must be on for many of these metrics to be sent.

Additional tags:

image_file_name: Name of the image file associated with these metrics.
target_name: Name of the target imaged as defined in the sequencer’s target field. This tag is omitted if no target name is defined.
sequence_title: The title or name of the running sequence
camera_name: Name of the camera
readout_mode: Name of the readout mode the camera is operating under

Metric	Definition	Type
`image_mean`	Pixel mean value	double
`image_median`	Pixel median value	double
`image_std_deviation`	Pixel value stardard deviation	double
`image_mad`	Pixel value mean average deviation	double
`image_min_adu`	Minimum pixel ADU value	integer
`image_min_adu_count`	Number of occurences of min. pixel ADU value	integer
`image_max_adu`	Maximum pixel ADU value	integer
`image_max_adu_count`	Number of occurences of max. pixel ADU value	integer
`image_hfr`	Average star HFR	double
`image_hfr_std_deviation`	Standard deviation of measured stars’ HFR	double
`image_star_count`	Count of stars in the image	integer
`image_rms_avg_ra_arcsec`	Average guiding RMS of the RA axis during image exposure	double
`image_rms_avg_dec_arcsec`	Average guiding RMS of the declination axis during image exposure	double
`image_rms_avg_arcsec`	Combined average RMS during image exposure	double
`image_rms_peak_ra_arcsec`	Peak guiding RMS of the RA axis during image exposure	double
`image_rms_peak_dec_arcsec`	Peak guiding RMS of the declination axis during image exposure	double
`image_rms_peak_arcsec`	Combined peak RMS during image exposure	double