Created question in FIWARE Q/A platform on 05-01-2016 at 16:01
Please, ANSWER this question AT http://stackoverflow.com/questions/34615737/orion-context-broker-query-by-location-with-no-elements

Question:
Orion Context Broker - Query by location with no elements

Description:
I'm working with version 0.25.0 of Orion Context Broker.

If I load the context broker only with context entities and I search for entities into a specific area, everything seems to work fine:

(curl localhost:1026/v1/queryContext?limit=100 s -S --header 'Content-Type: application/json' --header 'Accept: application/json' -d @ | python -mjson.tool) <<EOF
{
"entities":[

{ "type":"Dispositivo_tmp", "isPattern":"true", "id":".*" }

],
"restriction": {
"scopes": [
{
"type": "FIWARE::Location",
"value": {
"circle":

{ "centerLatitude": "43.322361", "centerLongitude": "-1.983222", "radius": "1500" }

}
}
]
}
}
EOF

I get a response with the context entities located into that area:

...
{
"contextElement": {
"attributes": [
{
"metadatas": [

{ "name": "location", "type": "string", "value": "WGS84" }

],
"name": "position",
"type": "coords",
"value": "43.3221, -1.9831"
},

{ "name": "pressure", "type": "integer", "value": "1" }

,

{ "name": "temperature", "type": "float", "value": "25" }

],
"id": "CE_5.1",
"isPattern": "false",
"type": "Dispositivo_tmp"
},
"statusCode":

{ "code": "200", "reasonPhrase": "OK" }

}
]
}

And if there are no elements into the defined area, I get the expected response:

{
"errorCode":

{ "code": "404", "reasonPhrase": "No context element found" }

}

The problem arises if I load the context broker with context registrations too. If I have both context entities and context registrations on the context broker and I check for context entities into an area I know is empty, I won't get any response or I will get this one:

{
"errorCode":

{ "code": "200", "reasonPhrase": "OK" }

}

And seems that the larger is the amount of context registrations loaded in the context broker, more time takes to get a (negative) response from the system.

On the same scenario, there is no problem if I look for context entities into an area with elements. In this case I will get the correct response.

Is there any sense on all that?

EDIT:

I have seem that this behaviour is due to the URL defined when creating the context registrations. Due to a misspelling on it, the system was trying to contact with a device using a non-existing URL.

Thanks