No Trend Data Source available. Please add Tags from the Tag Browser panel

8.1.25

When I change between pages (using the template menu from IA), I have two pages each with its own power chart in a flex container. For about 3 seconds I get a message at the bottom as per thread title.

I have 3 tags on one chart, and one tag on the other. Default settings, realtime last 8 hours.

One perspective session is open on Chrome.

Is this normal?

Pretty normal for all the charts we use, normally its the lag for the query to the database for the 500 or so tags it uses to generate each plot.

I would define that as normal for 500 tags. But 1 and 3?

IA stats report ~1% CPU usage, top reports ~43% java usage. @pturmel ?

It is common for top to report cpu% on a per-core basis, so a process hogging five cores would show 500%. You'll have to dig around in its man-page to confirm.

Thanks,

In the above screenshot, is "100.0 wa" one of my cores flat lined at 100%?

Yes, "wa" is I/O wait, so that core is 100% busy with I/O. (The man-page has all of the details.

1 Tag on a chart is ~500(i think this is configurable) values to render the line from historical data.
If that tag has more than the requested amount of values for the time period on the chart, it Aggregates the data to provide the right amount of values to render.
This request is processed on the database, then sent to the gateway, which sends the data to the perspective session you are viewing it on, then the local browser has to render the graphics using its rendering engine. This takes time, and depending on load on various parts of that chain, it takes longer or shorter times.

Ah yes. Sorry I read that as 500 unique tags, not 500 data points