cygnus mongo sink and meta data storing - fiware

Question

I tried to stored this meta data entity but seems like cygnus is only storing entity data no meta data was stored in the data base.
Here is how I update my entity using NGSI v1 updateContext
{
"contextElements": [
{
"type": "dummyMeta",
"isPattern": "false",
"id": "dummyMeta",
"attributes": [
{
"name": "dummy",
"type": "float",
"value": "26.5",
"metadatas": [
{
"name": "accuracy",
"type": "float",
"value": "1"
}
]
}
]
}
],
"updateAction": "APPEND"
}
Here is the payload subscription:
{
"entities": [
{
"id": "dummyMeta",
"type": "dummyMeta",
"isPattern": "false"
}
],
"attributes": [
"dummy"
]
,
"reference": "http://cygnusserver.ddns.net:5050/notify",
"duration":"P1M",
"notifyConditions": [
{
"type": "ONCHANGE",
"condValues": [
"dummy"
]
}
],
"throttling": "PT5S"
}
here is how it is stored in the data base
> db['kura_/egmmqtt_dummyMeta_dummyMeta'].find().sort({$natural:-1})
{ "_id" : ObjectId("57c929d8902531258a3c6ed0"), "recvTime" : ISODate("2016-09-02T07:27:18.331Z"), "attrName" : "dummy", "attrType" : "float", "attrValue" : "26.5" }
{ "_id" : ObjectId("57c92990902531258a3c6ecc"), "recvTime" : ISODate("2016-09-02T07:26:04.148Z"), "attrName" : "dummy", "attrType" : "float", "attrValue" : "26.5" }
What am I missing to be able to store the whole information (data and metadata) about the attribute?
Thanks in advance for your help!

Answer 1

MongoDB sink does not save the metadata by design. It is a requirement by our internal products currently using Cygnus.
Being said that, I think it should not be very difficult to modify the code by your side in order to save the metadata.
Alternatively, I can create an issue about optionally save metadata when configured through a configuration parameter. Nevertheless, I cannot commit with an implementation date.