STA Client Deployed at https://multicare.bk.tudelft.nl/rime/

[justinschembri]

Hello all!

I've deployed a STA client at https://multicare.bk.tudelft.nl/rime.

There's a button to connect to several STA services (interoperability :-)). Altough it defaults to a FROST server I manage, you can easily point to the Brabandse testbed server at https://sta.wbd-rd.nl/FROST-Server. Just make sure to add the basic auth credentials before pressing connect. There's also the larger network at at https://airquality-frost.k8s.ilt-dmz.iosb.fraunhofer.de available to stress test the client a bit.

@Kattouw will be nice to add the Collaborall to the list soon

There's a health check button which makes a request to "get the latest observation from any of the datastreams of all Things" namely, this request:

https://<service_url>/FROST-Server/v1.1/Things
$expand=Datastreams($expand=Observations($top=1;$orderby=phenomenonTime%20desc))
&$top=1000
&$skip=0
&$orderby=%40iot.id%20asc

It could be useful for a quick visual overview of what we've all connected to the testbed servers.

Hope its useful!

[hylkevds]

Cool!

I found a bug: When selecting the v1 API version, it leaves out the .0 in the URL:
https://sensorthings-wq.brgm-rec.fr/FROST-Server/v1/Things?$expand=Locations&$top=10000
That's not a valid URL!

It may also be nice to detect the version from the URL. If I paste https://ogc-demo.k8s.ilt-dmz.iosb.fraunhofer.de/FROST-StaV2Full/v2.0 it doesn't change the version to 2.0, but it does strip out the v2.0/ and replace it with v1/ if I have version 1.0 selected.

[hylkevds]

The v2.0 API version has the same problem. It puts v2 in the URL.

[justinschembri]

Good spot, fixed this and will push changes!

[hylkevds]

Feature request: Use $select to reduce the transferred amount of data:

https://airquality-frost.k8s.ilt-dmz.iosb.fraunhofer.de/v1.1/Things?$expand=Datastreams($expand=Observations($top=1;$orderby=phenomenonTime%20desc))&$top=1000&$skip=0&$orderby=%40iot.id%20asc
Transferred: 355kB (Size 7.61MB)

https://airquality-frost.k8s.ilt-dmz.iosb.fraunhofer.de/v1.1/Things?$select=id&$expand=Datastreams($select=id;$expand=Observations($select=phenomenonTime;$top=1;$orderby=phenomenonTime desc))&$top=1000&$skip=0&$orderby=%40iot.id asc
Transferred: 70kB (Size 2.03MB)

[justinschembri]

Indeed, leaner. I've implemented this.

The health check-feature for very large networks (e.g., https://sensorthings-wq.brgm-rec.fr) is quite cumbersome. I believe the bottleneck is server side, because the query is a a three table join (?).

For example, this query:

https://sensorthings-wq.brgm-rec.fr/FROST-Server/v1.0/Things?$select=id&$expand=Datastreams($select=id;$expand=Observations($select=phenomenonTime;$top=1;$orderby=phenomenonTime%20desc))&$top=1000&$skip=17000&$orderby=%40iot.id%20asc

Was 24 seconds waiting for server response, and 17 seconds downloading the 21MB file.

[hylkevds]

That BRGM server is running an old version of FROST that is missing many of the optimisations for larger result sets. It still builds the entire response in memory before it starts sending it to the client. So don't trust its performance too much :)