Longtime Charts



I want to show on my dashboard some charts until 3 weeks back.
But after 5 days the dashboard gets really slow.
I think so because there are to much datas.
After restarting the flow its much faster now but i also lose the stored datas for the charts.

Is there a way to show longtime charts without the dashboard getting slow?




Yes probably too much data. You need to think a bit about the size of the chart. Typically the default 6 blocks wide will be about 300 pixels. So if we aim for 300 points over 3 weeks is about 15 to 20 data points per day. So let's call that one per hour.

So you need to reduce your data rate to something like that. Up to you how you do that. Throw data away, average it, create min/mean/max etc. Up to you.



Whats about Grafana.
Can I create a MySQL DB to store the datas and send them to Grafana?



You can use Grafana with MySQL, the query syntax is a bit weird though. Much easier, if you are just doing time series to use InfluxDB with Grafana.