"Signal K to InfluxDb 2" plugin. How to specify write-frequency

[akakniven]

Hi. As far as I can remember, there was an option to specify how often data should be written to InfluxDB. Now, I've switched to InfluxDB V2, and no longer see this option in the plugin parameters. Any ideas?

[tkurki]

Nobody has implemented this for Influxdb 2 plugin.

Feel free to add an issue to track this in the plugin repository at https://github.com/tkurki/signalk-to-influxdb2/issues

[kfafel]

@akakniven what are you seeing for the frequency of writes to InfluxDB without this capability/parameter? I'm seeing ~30 second delay between SignalK and InfluxDB. If you're seeing the same, the resolution parameter may be what I'm needing also.

[tkurki]

Are we talking about ”how often are values that are buffered in memory actually written to influxdb in a batch” which is flushInterval and configurable already OR ”write data for each path and source combination once every x milliseconds and discard more frequent updates”?

Default flushInterval is 60 seconds unless specified in the plugin configuration.

[akakniven]

I would say yes to the second option. Typically, what i prefer, is downsampled, synchronized data, with minimum possible «null» values. I dont see the need for storing anything with higher sampling rate than typically 10-30 sec.

[kfafel]

In my case, I was referring to the former. That is, the time between sensor data (e.g. RPM sensor) being in SignalK (e.g. visible in Data Browser) to the time that it's committed in InfluxDB and readable. I've played with flushInterval with no apparent change. So, I might have something else going on. My bigger picture is a Grafana dashboard (which may have it's own latency issues) at my helm. As such, 10 seconds or less between updates would be my goal.
I don't want to derail @akakniven's original intent of this conversation, so I'll keep investigating and may start a new thread if needed.

Edit: I realized a much simpler solution -- Grafana connect straight to SignalK via a websocket. :) :)

[tkurki]

Yep, for gauges ws is the way to go, but you can save and eat your cake in history graohs if you combine the sk history api (to retrieve older values) and then stream updates via WebSocket to get a live, updating graph.

This is what my https://github.com/tkurki/signalk-grafana does with its Signal K datasource.

In case you want to give it a try let’s switch to Slack if you need help. The easiest way to get started is by building a Docker container for it, unless you are well versed with custom Grafana plugins.

[tkurki]

Version 1.6.1 has now the same configuration option as the old plugin for limiting write frequency per path and source.

https://github.com/tkurki/signalk-to-influxdb2/releases