real-time-data visualization?!

[alexander_christian]

Is there a preferred way to visualize "in real time" incoming data?

Assume we have an IoT device that is sending about every 1-2 sec messages to the IoT Service, which is linked to Thing in Leonardo IoT and I want to have an Web-UI which is showing the device's data in real time: Is it possible to somehow "stream" the data that is received at Leonardo IoT/the "Thing" to the UI instead of doing polling? Something like websocket or SSE...

If so: Could you please point me to the right documentation? I searched the docs, but was not able to find something that is providing "realtime data". Just found ways to poll for (new) data from the Thing.

If such kind of "real time" is not possible: Is there a limit of how fast we can poll the Thing?

best regards,

Alex

[fvviviani · Accepted solution]

Hello,

As far as I know there is no "streaming" mode from SAP Leonardo IoT. A way could be that of implementing an autorefresh and thus making the API call again (i.e., polling like you were saying).

The full list of API endpoints is available at:

https://help.sap.com/viewer/080fabc6cae6423fb45fca7752adb61e/1906a/en-US/dcaa38dda9e14fbc887a3ebda36...

BR,

Federico

[alexander_christian · Accepted solution]

My current workaround would be:

Setup "Message Processing" in IoT Service: Send all received messages to an HTTPS endpoint.

Thus, we could implement a small cloud foundry based backend-application that receives those forwarded device messages/measures and provide those messages via websocket to those who need "real time data" (f.i. web based UIs).

First tests showed, that it takes round about 35..40ms between "sending from device to IoT Service via HTTPS" until "data is received on configured Message Processing HTTPS endpoint".

That's not exactly real-time (because of additional 35..40ms), but its okay for our pupose. Of course, message forwarding time may differ, but overall, it's okay (up to 200..300ms I would say).

thanks for clarifying fvviviani

br,

Alex

[fvviviani · Accepted solution]

Hello alexander.christian,

Your solutions sounds reasonable to me.

Thanks for sharing!

Federico