What I have

Docker Containers:

Orion CB
MongoDB

What I do

I use the REST API (NGSIv2) so I:

Create an entity (using POST)
Update the values from this entity (using PUT)
Get the value from the entity (using other app: GET)

My question

Is there any way (inherent to ORION) to have the full history of values of this entity? Something like a queue of messages, or so, being them the values of this entity.

If not, which mechanism should I use (inherent to ORION again) to be able to build it in my second app?

I guess I expect to have a subscription mode or whatever so I get a notification of a new value (public/subs model?) still using the REST API in my second app, not needing it to have hard-coded when a new value of the entity will be available at ORION, since this may be unknown even for me.

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answered 2018-05-01 08:08:02 +0200

flegall
11 ●1 ●1 ●3

Hi

As far as I know, there is not such queuing capabilities in Orion. At least you vacan add persistence to Orion with Cygnus + a dB like MongoDB. See: http://fiware-cygnus.readthedocs.io/e...startguide/

Then, if you want to go further, you can look at 2 side components:

STH (Short Term History) comet: https://fiware-sth-comet.readthedocs....

Or alternatively, if the 'fire and forget' approach of Orion is the one bothering you, you may investigate rush : https://github.com/telefonicaid/fiwar... (never tried it)

Franck

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answered 2018-05-02 09:27:05 +0200

pasquy73
21 ●8 ●10 ●14

Hi, Orion doesn't store own context. This policy is right, because if your context is composed by many attributes, and you update it, any second ... after few days (for example) the internal database (mongo) of Orion will became full and your service will fault.

To store the context you can use the Cygnus adapter and you can chose, for your app, the right storage system (ex. mongo, mysql, ckan, cosmos big data, etc...) that it depends how much data you want to manage.

pasquy