I think it could be a good idea to develop a Cygnus Sink to Neo4J. Cygnus has recently changed their architecture to use Apache NiFI

The Cygnus team (GING) can help you in giving some hints on how to develop a new Sink for Neo4J.

Thanks

HI Giovanni,

Currently, Cygnus doesn't support Neo4J as storage service, we have a roadmap for including some other stores systems as processors in the new version of Cygnus v2.0.0 (https://fiware-cygnus-ld.readthedocs.io/en/latest/). However Neo4J was not considered for being implemented yet, but we can add in the future (low priority). On the other hand, I have been trying to work with new Cygnus (based on NiFi ) and Neo4J and I found some external resources for doing this integration. @jonathantelfer provides a neo4j processor and controller for NiFi (https://github.com/jonathantelfer/nifi-neo4j) and you can add this code only putting the nar file inside of your Cygnus lib directory but this is generic processor so you have to use other processors for manage the NGSI notification that you receive for the Context Broker. This approach force you to use many processors and the flow will be more or less as follows:
1) Configure your Neo4J controller (available after your put the jonathantelfer's nar inside of the Cygus lib directory)
2) For receiving the notifications of the context broker you need to add a Listen Http Processor configured for receiving the NGSi notification. In Cygnus version, you can use the Orion-to-Mysql template with the preconfigured Listen HTTP processor
3)Use EvaluateJsonPath processor for getting the data[0] element of your notification.
4)Use another EvaluateJsonPath for adding each element of your entity as flow file attribute
5)Use Put Cypher for writing your NGSI notification inside of your Neo4J database

This figure shows more or less the processor that you need

This procedure is a little complex but works.

Another approach is building your own NGSIToNeo4j processor and controller and contribute to the Cygnus GE of the FIWARE community. For doing so, you also need to follow the same process described above, but with other considerations. If you are interested in developing this processor please create a thread in the Cygnus Github repo (https://github.com/ging/fiware-cygnus) and I will plan that.

The issue has been emailed:

• Time sent: 19/Dec/18 6:08 PM
• To: Giovanni.VAGLICA@ec.europa.eu
• with subject: *(HELP-14879) [Fiware-tech-help] Question about graphical interface : Neo4J Cygnus sink *
  

HI Giovanni,

Currently, Cygnus doesn't support Neo4J as storage service, we have a roadmap for including some other stores systems as processors in the new version of Cygnus v2.0.0 (https://fiware-cygnus-ld.readthedocs.io/en/latest/). However Neo4J was not considered for being implemented yet, but we can add in the future (low priority). On the other hand, I have been trying to work with new Cygnus (based on NiFi ) and Neo4J and I found some external resources for doing this integration. @jonathantelfer provides a neo4j processor and controller for NiFi (https://github.com/jonathantelfer/nifi-neo4j) and you can add this code only putting the nar file inside of your Cygnus lib directory but this is generic processor so you have to use other processors for manage the NGSI notification that you receive for the Context Broker. This approach force you to use many processors and the flow will be more or less as follows:
1) Configure your Neo4J controller (available after your put the jonathantelfer's nar inside of the Cygus lib directory)
2) For receiving the notifications of the context broker you need to add a Listen Http Processor configured for receiving the NGSi notification. In Cygnus version, you can use the Orion-to-Mysql template with the preconfigured Listen HTTP processor
3)Use EvaluateJsonPath processor for getting the data[0] element of your notification.
4)Use another EvaluateJsonPath for adding each element of your entity as flow file attribute
5)Use Put Cypher for writing your NGSI notification inside of your Neo4J database

This figure shows more or less the processor that you need

This procedure is a little complex but works.

Another approach is building your own NGSIToNeo4j processor and controller and contribute to the Cygnus GE of the FIWARE community. For doing so, you also need to follow the same process described above, but with other considerations. If you are interested in developing this processor please create a thread in the Cygnus Github repo (https://github.com/ging/fiware-cygnus) and I will plan that.