RRD4J Presinstence (on Synology with OpenHAB 1.8.1)


I’m impressed how simple the configuration of OpenHAB looks like, but struggling with some Details :blush:
For rrd4j-persistence it seems to be that only «openhab.cfg», «default.sitemap» and «rrd4j.persist» are needed to be configured. (see my files {i.e. extracts of the files} below).
The rrd-file exists: «volume1/@appstore/OpenHAB/etc/rrd4j/strom_w.rrd» (rights rw-r–r-- / Owner: openhab)

But unfortunatley the chart does not contain data (i.e. no y-axis data).

What do i have to configure/check in order to display the Data in the Chart?

KR Urs

Synology DS1513+
DSM 6.0-7321 Update 3
OpenHab 1.8.1-001

// openhab.cfg (extract only)
//openhab.cfg END

// default.sitemap (extract only)
Chart item=Strom_W period=h refresh=10000
// default.sitemap END

// rrd4j.persist (whole file)
Strategies {
everyMinute : "0 * * * * ?"
everyHour : "0 0 * * * ?"
everyDay : "0 0 0 * * ?"
default = everyChange
Items {
Strom_W : strategy = restoreOnStartup, everyChange
// rrd4j.persist END

You have to use the everyMinute strategy.:

Strom_W : strategy = everyMinute, everyChange, restoreOnStartup

Hi Udo

Yes, it works with

Strom_W : strategy = everyMinute, everyChange, restoreOnStartup

I will do some tests to get the Point (i.e sequence wrong or everyChange can not be the only strategy…
Unfortunately https://github.com/openhab/openhab/wiki/Persistence is not so detailed…

Thank you!


The reason is, building the chart needs 1 Datapoint per Minute, so everyMinute as strategy is mandatory, while everyChange will improve data accuracy, restoreOnStartup is only needed to reload the last known state to the item when restarting openHAB.

Thank you!
It worked. :relaxed: