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I have Orion working seamlessly, saving entities and retrieving them.

But I'd like to know which is the recommended way to insert (and/or retrieving) a sequence of values for an entity, not updating its value, but adding a new value to the entity, so later I can retrieve all values stored for an specific entity ID and "draw" the evolution in a graph.

Updated: I've seen that it may be posible to do it subscribing to a Cosmos instance. Is this the recommended way?

Thanks!

fgalan
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medaqueno
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1 Answers1

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The recommended way for creating historics in FIWARE is through the Cygnus tool. It is a connector that, taking advantage of the subscription-notification mechanism, subscribes to an Orion instance in order to be notifed each time certain entities' attributes change.

Cygnus has been designed for persisting the data in several storages: HDFS (Cosmos file system is a HDFS), MySQL, CKAN, MongoDB, Kafka, STH/Comet... (and more to come). For each one of them, a particular configurable module (sink, if using the Flume technology jargon) has been created. Just choose the most convenient storage for your application logic.

frb
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  • Is the Cygnus tool available on the Orion ContextBroker Global Instance? – Andrea Sassi Dec 01 '15 at 16:16
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    I'll recommend you to install it by your own. It is pretty simple as stated here: http://fiware-cygnus.readthedocs.org/en/develop/ – frb Dec 02 '15 at 10:41