Browse historical sensor data


(Klim Bim) #1

Hi openhabber,

I am totally excited to play around with openhab. In future ideally I would like it to gather weather data, drive my farmbot for decisions on this weather data (e.g. watering yes/no) and to become the centre for automation (e.g. outside light switchting based on sunlight).

At the moment I would like to get used to view data from those sensors in openhab. I like the habpanel approach, as I am not very much the code lover :wink: as far as I found out, there are generally two ways at the moment to store and access (view) data: rdd4j and mysql or grafana and influxDB, right?

So I played around a little bit with mysql and rdd4j but I wasn´t able to zoom in or to jump to historic data. Would that be possible with influxDB and grafana?

Thanks a lot for your help in advance, I am very excited in digging deeper into the openhab world, great what you achieved and present to the community as open source!!!

Cheers
Klim


(Udo Hartmann) #2

rrd4j, mysql and influxdb are used for persistence, while grafana is used to generate graphs (there is a built in mechanism in openHAB, too, but this is only basic graphing)
In question of the built in graphing, you are limited to rrd4j. grafana on the other hand has the ability to use more data sources such as influxdb and (My)SQL, but not rrd4j.

Speaking of rrd4j, this is a round robin database, the data is less accurate for old time slots. The end of the built in graph is always “now”, while the begin of the graph can be chosen to be “now - 1h”, “now - 4h”, “now - 12h”, “now - 24h”, “now - 72h”, …)
When using grafana, one is able to chose the duration and begin/end of period free.
Take a look at http://play.grafana.org/d/000000012/grafana-play-home?orgId=1 to see, what’s grafana like…


(Klim Bim) #3

Hey @Udo_Hartmann thanks very much for the fast reply!

Grafana seems to be the viewing and data analysis toolkit I might need, thanks very much for the Demo link!!! So this could be used with the same functionality in a habpanel as shown in the demo?
As explained here:
InfluxDB+Grafana persistence and graphing ?

Is there any other hint when to take influxDB or mysql? At least with mysql I do have some very limited experience…

Thanks so much for support!!!


(Udo Hartmann) #4

The choice of persistence service depends on some factors:

  1. What kind of Data: e.g. rrd4j is not able to store strings or more special values (afaik even a switch or contact might be a problem)
  2. speed: e.g. influxdb is build especially for time based data series, so it should be very fast for graphing (but I did no speed tests at all…)
  3. Reuse of data: you might want to get persisted data to use it without openHAB, it comes in handy if the data is stored in a structured database with plenty tools (e.g. sql)
  4. Space: rrd4j uses static files to store data, there is no growing, because old data is thinned out and discarded automatically. mapdb does persistence for only the actual value, so here no growing, too (but no historical data at all, but only data to restore the state on boot up.
  5. Experience: As I’m pretty familiar with MySQL/MariaDB (at least I managed to setup…:wink: ) I chose this engine to store my data.
  6. presence of service: As I have already set up a MariaDB service, why should I use another engine…

So in the end you have to decide, which data should be persisted in which way (of course you can store the same data in different persistence services)