FIWARE-Orion Context Broker metadata updates trigger notifications

3
votes

I'm using 3 FIWARE GEs: IDAS+Orion+CEP.
As reported in the Orion documentation (https://github.com/telefonicaid/fiware-orion/blob/develop/doc/manuals/user/metadata.md) "changing the metadata of a given attribute or adding a new metadata element is considered a change even if attribute value itself hasn't changed". Is there a way to send notifications from Orion only if the value of the attribute specified in the subscription changes?

I've tried the solution proposed in the documentation, delete and re-create the attribute, in order to remove the metadata. But, since the messages to Orion are produced by IDAS, the metadata are created with the new communication.

Thanks.

UPDATE:

GEs Version:
- Orion - 0.26.1-next
- IoTAgent (IDAS) - 1.3.1

The metadata added by IDAS are:

"attributes" : [ { "name" : "temperature", "type" : "int", "value" : "37", "metadatas" : [ { "name" : "TimeInstant", "type" : "ISO8601", "value" : "2015-12-29T12:46:04.421859" } ] } ]

Specifically, from mongodb query:

"temperature" : { "value" : "37", "type" : "int", "md" : [ { "name" : "TimeInstant", "type" : "ISO8601", "value" : "2015-12-29T12:46:04.421859" } ], "creDate" : 1450716887, "modDate" : 1451393164 }

1
notificationssubscriptionfiwarefiware-orion
In order to have all the information, which particular metadata is being sent by IDAS (I understand that changing the medatada value each update) causing notifications sent by Orion? In addition, which Orion and IDAS versions are you using? Please, edit your question post to include that infromation. Thanks! – fgalan
Thanks for the update. I understand that the issue is that you are getting updates in which the temperature value doesn't change but the TimeStamp metadata value is changing. Is that correct? – fgalan
Just to be sure... could you cite the procedure from which you have downloaded IoTAgent/IDAS and the procedure used to install, please? Thansk! – fgalan
Yes, correct, the Timestamp metadata value is changing, as it should be indeed. The IoTAgent has been downloaded from the official git repo, and installed via the Dockerfile. – Marco Fagiani

1 Answers

0
votes

As far as I know, TimeInstant metadata sending from IDAS/IoTAgent to Orion couldn't be disabled by the time being.

A possible workaround could be to have a proxy between IDAS and Orion ir order to remove the TimeInstant metadata (or the whole metadata field in JSON to prevent some other metadata could be causing a similar problem).