Orion-QL订阅配置

Question

我有带很多物联网传感器的设备。我想对这些设备进行批量读取，并将这些数据批量写入CrateDB。每1秒从传感器获取100个数据。

例如，如何使用量子跃迁代理将5秒的批处理数据(500个数据)与一起写入CrateDB?我是否应该在Orion订阅(节流等)中进行此配置？

Answer 1

使用NGSI-v2，可以使用/v2/op/update端点实现批处理更新，例如：

curl -L -X POST 'http://localhost:1026/v2/op/update' \
-H 'Content-Type: application/json' \
--data-raw '{
  "actionType":"update",
  "entities":[
    {
      "id":"urn:ngsi-ld:Product:001", "type":"Product",
      "price":{"type":"Integer", "value": 1199}
    },
    {
      "id":"urn:ngsi-ld:Product:002", "type":"Product",
      "price":{"type":"Integer", "value": 1199},
      "size": {"type":"Text", "value": "L"}
    }
  ]
}'

使用NGSI-LD，您可以使用/ngsi-ld/v1/entityOperations/upsert。

curl -L -X POST 'http://localhost:1026/ngsi-ld/v1/entityOperations/upsert' \
-H 'Content-Type: application/json' \
-H 'Link: <http://path-to-context/ngsi-context.jsonld>; rel="http://www.w3.org/ns/json-ld#context"; type="application/ld+json"' \
-H 'Accept: application/ld+json' \
--data-raw '[
    {
      "id": "urn:ngsi-ld:TemperatureSensor:002",
      "type": "TemperatureSensor",
      "category": {
            "type": "Property",
            "value": "sensor"
      },
      "temperature": {
            "type": "Property",
            "value": 21,
            "unitCode": "CEL"
      }
    },
    {
      "id": "urn:ngsi-ld:TemperatureSensor:003",
      "type": "TemperatureSensor",
      "category": {
            "type": "Property",
            "value": "sensor"
      },
      "temperature": {
            "type": "Property",
            "value": 27,
            "unitCode": "CEL"
      }
    }
]'

您没有说明您的多传感器是否能够发送NGSI呼叫--如果它不能发送NGSI，但能够以其他格式发送批处理读数，那么您只需要一个微服务来为您进行转换--这里可以在GitHub上找到一个例子--有关代码的评论可以在FIWARE基金会的视频教程中找到。

一旦您安全地以NGSI格式发送设备数据，您就可以解决问题的后半部分。QuantumLeap为NGSI-v2和NGSI-LD都提供了教程，它们的关键是创建一个通知任何更改的订阅。

NGSI-v2

curl -iX POST \
  'http://localhost:1026/v2/subscriptions/' \
  -H 'Content-Type: application/json' \
  -H 'fiware-service: openiot' \
  -H 'fiware-servicepath: /' \
  -d '{
  "description": "Notify QuantumLeap of count changes of any Motion Sensor",
  "subject": {
    "entities": [
      {
        "idPattern": "Motion.*"
      }
    ],
    "condition": {
      "attrs": [
        "count"
      ]
    }
  },
  "notification": {
    "http": {
      "url": "http://quantumleap:8668/v2/notify"
    },
    "attrs": [
      "count"
    ],
    "metadata": ["dateCreated", "dateModified"]
  }
}'

NGSI-LD

curl -L -X POST 'http://localhost:1026/ngsi-ld/v1/subscriptions/' \
-H 'Content-Type: application/ld+json' \
-H 'NGSILD-Tenant: openiot' \
--data-raw '{
  "description": "Notify me of all feedstock changes",
  "type": "Subscription",
  "entities": [{"type": "FillingLevelSensor"}],
  "watchedAttributes": ["filling"],
  "notification": {
    "attributes": ["filling", "location"],
    "format": "normalized",
    "endpoint": {
      "uri": "http://quantumleap:8668/v2/notify",
      "accept": "application/json"
    }
  },
   "@context": "http://path-to-context/ngsi-context.jsonld"
}'

除非您只想对传入的数据进行采样，否则不需要使用throttling参数。