Context Information Management in IoT enabled smart systems - the basics
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- The Orion Context Broker is used for context information management in IoT systems and allows storing and retrieving context data. - It uses an entity-attribute model where context information is represented by entities with attributes. Producers can create, update, and retrieve this context data from the broker using RESTful HTTP requests. - Consumers can subscribe to the broker to receive notifications of attribute updates that match certain criteria. The broker notifies subscribers by invoking callback URLs provided in the subscription.
![Orion Context Broker Basic Operations
Entities
• GET /v2/entities
• Retrieve all entities
• POST /v2/entities
• Creates an entity
• GET /v2/entities/{entityID}
• Retrieves an entity
• [PUT|PATCH|POST] /v2/entities/{entityID}
• Updates an entity (different “flavours”)
• DELETE /v2/entities/{entityID}
• Deletes an entity
8](https://image.slidesharecdn.com/contextinformationmanagementiniot-enabledsmartsystems-thebasics-170822165254/85/Context-Information-Management-in-IoT-enabled-smart-systems-the-basics-8-320.jpg)
![Quick Usage Example: Filters (1)
22
200 OK
Content-Type: application/json
...
[
{
"id": "Room2",
"pressure": 730,
"temperature": 29,
"type": "Room"
}
]
GET <cb_host>:1026/v2/entities?options=keyValues&q=temperature>27](https://image.slidesharecdn.com/contextinformationmanagementiniot-enabledsmartsystems-thebasics-170822165254/85/Context-Information-Management-in-IoT-enabled-smart-systems-the-basics-22-320.jpg)
![Quick Usage Example: Filters (2)
23
200 OK
Content-Type: application/json
...
[
{
"id": "Room1",
"pressure": 720,
"temperature": 25,
"type": "Room"
}
]
GET <cb_host>:1026/v2/entities?options=keyValues&q=pressure==715..725
The full description of the Simple
Query Language for filtering can be
found in the NGSIv2 Specification
document](https://image.slidesharecdn.com/contextinformationmanagementiniot-enabledsmartsystems-thebasics-170822165254/85/Context-Information-Management-in-IoT-enabled-smart-systems-the-basics-23-320.jpg)
![Quick Usage Example: Subscription
POST <cb_host>:1026/v2/subscriptions
Content-Type: application/json
…
{
"subject": {
"entities": [
{
"id": "Room1",
"type": "Room"
}
],
"condition": {
"attrs": [ "temperature" ]
}
},
"notification": {
"http": {
"url": "http://<host>:<port>/publish"
},
"attrs": [ "temperature" ]
},
"expires": "2026-04-05T14:00:00.00Z"
}
201 Created
Location: /v2/subscriptions/51c0ac9ed714fb3b37d7d5a8
...
26](https://image.slidesharecdn.com/contextinformationmanagementiniot-enabledsmartsystems-thebasics-170822165254/85/Context-Information-Management-in-IoT-enabled-smart-systems-the-basics-26-320.jpg)
![POST /publish HTTP/1.1
Content-type: application/json; charset=utf-8
Ngsiv2-AttrsFormat: normalized
…
{
"subscriptionId": "574d720dbef222abb860534a",
"data": [
{
"id": "Room1",
"type": "Room",
"temperature": {
"type": "Float",
"value": 19,
"metadata": {}
}
}
]
}
Quick Usage Example: Notification
27
25
19](https://image.slidesharecdn.com/contextinformationmanagementiniot-enabledsmartsystems-thebasics-170822165254/85/Context-Information-Management-in-IoT-enabled-smart-systems-the-basics-27-320.jpg)
![List existing subscriptions
28
200 OK
Content-Type: application/json
…
[{
"id": " 51c0ac9ed714fb3b37d7d5a8 ",
"expires": "2026-04-05T14:00:00.00Z",
"status": "active",
"subject": {
"entities": [{
"id": "Room1",
"type": "Room"
}],
"condition": {
"attrs": ["temperature"]
}
},
"notification": {
"timesSent": 3,
"lastNotification": "2016-05-31T11:19:32.00Z",
"lastSuccess": "2016-05-31T11:19:32.00Z",
"attrs": ["temperature"],
"attrsFormat": "normalized",
"http": {
"url": "http://localhost:1028/publish"
}
}
}]
The full description of the
subscription object (including all its
fields) can be found in the NGSIv2
Specification
GET <cb_host>:1026/v2/subscriptions](https://image.slidesharecdn.com/contextinformationmanagementiniot-enabledsmartsystems-thebasics-170822165254/85/Context-Information-Management-in-IoT-enabled-smart-systems-the-basics-28-320.jpg)
![201 Created
...
Batch Operation Example: Create Several Rooms
POST <cb_host>:1026/v2/op/update
Conten-Type: application/json
...
{
"actionType": "APPEND",
"entities": [
{
"type": "Room",
"id": "Room3",
"temperature": {
"value": 21.2,
"type": "Float"
},
"pressure": {
"value": 722,
"type": "Integer"
}
},
…
31
…
{
"type": "Room",
"id": "Room4",
"temperature": {
"value": 31.8,
"type": "Float"
},
"pressure": {
"value": 712,
"type": "Integer"
}
}
]
}](https://image.slidesharecdn.com/contextinformationmanagementiniot-enabledsmartsystems-thebasics-170822165254/85/Context-Information-Management-in-IoT-enabled-smart-systems-the-basics-31-320.jpg)
Context Information Management in IoT enabled smart systems - the basics
- 1. IoT in the FIWARE Platform - 2: Context Information Management in IoT-enabled Smart Systems: The basics Fernando López Aguilar FIWARE Cloud and Platform Senior Expert fernando.lopez@fiware.org @flopezaguilar
- 2. • Orion Context Broker • Creating and pulling data • Pushing data and notifications • Batch operations • STH - Comet 2 Outline
- 4. Orion Context Broker • Main functions: – Context management – Context availability management (advanced topic) • HTTP and REST-based – JSON payload support • Context in NGSI is based in an entity-attribute model: Attributes • Name • Type • Value Entity • EntityId • EntityType 1 n “has” 4
- 5. Orion Context Broker in a nutshell Orion Context Broker Context Producers Context Consumers subscriptions update query notify notify update update DB 1026 1026 5
- 6. GET <cb_host>:1026/version { "orion" : { "version" : "1.6.0", "uptime" : "7 d, 21 h, 33 m, 39 s", "git_hash" : "aee96414cc3594bba161afb400f69d101978b39c", "compile_time" : "Mon Dec 5 08:38:58 CET 2016", "compiled_by" : "fermin", "compiled_in" : "centollo" } } 6 Orion Context Broker – check health
- 7. Two “flavours” of NGSI API • NGSIv1 – Original NGSI RESTful binding of OMA-NGSI – Implemented in 2013 – Uses the /v1 prefix in resource URL • NGSIv2 – A revamped, simplified binding of OMA-NGSI – Enhanced functionality compared with NGSIv1 (eg. filtering) – Stable, ready for production, version already available • Current NGSIv2 version is Release Candidate 2016.10 http://telefonicaid.github.io/fiware-orion/api/v2/stable • New features coming (http://telefonicaid.github.io/fiware-orion/api/v2/stable) – Uses the /v2 prefix in resource URL • Introduction to NGSIv2 – https://docs.google.com/presentation/d/1_fv9dB5joCsOCHlb4Ld6A- QmeIYhDzHgFHUWreGmvKU/edit#slide=id.g53c31d7074fd7bc7_0 7
- 8. Orion Context Broker Basic Operations Entities • GET /v2/entities • Retrieve all entities • POST /v2/entities • Creates an entity • GET /v2/entities/{entityID} • Retrieves an entity • [PUT|PATCH|POST] /v2/entities/{entityID} • Updates an entity (different “flavours”) • DELETE /v2/entities/{entityID} • Deletes an entity 8
- 9. Orion Context Broker Basic Operations Attributes • GET /v2/entities/{entityID}/attrs/{attrName} • Retrieves an attribute’s data • PUT /v2/entities/{entityID}/attrs/{attrName} • Updates an attribute’s data • DELETE /v2/entities/{entityID}/attrs/{attrName} • Deletes an attribute • GET /v2/entities/{entityID}/attrs/{attrName}/value • Retrieves an attribute’s value • PUT /v2/entities/{entityID}/attrs/{attrName}/value • Updates an attribute’s value 9
- 10. Create & Pull data 10
- 11. Context Broker operations: create & pull data • Context Producers publish data/context elements by invoking the update operations on a Context Broker. • Context Consumers can retrieve data/context elements by invoking the query operations on a Context Broker Context Consumer query Context Producer update Context Broker 11
- 12. Quick Usage Example: Car Create 201 Created 12 POST <cb_host>:1026/v2/entities Content-Type: application/json ... { "id": "Car1", "type": "Car", "speed": { "type": "Float", "value": 98 } }
- 13. Quick Usage Example: Car Speed Update (1) PUT <cb_host>:1026/v2/entities/Car1/attrs/speed Content-Type: application/json ... { "type": "Float", "value": 110 } 204 No Content … 13 In the case of id ambiguity, you can use "?type=Car" to specify entity type
- 14. Quick Usage Example: Car Speed Query (1) 200 OK Content-Type: application/json ... { "type": "Float", "value": 110, "metadata": {} } 14 You can get all the attributes of the entity using the entity URL: GET/v2/entities/Car1/attrs GET <cb_host>:1026/v2/entities/Car1/attrs/speed
- 15. Quick Usage Example: Car Speed Update (2) PUT <cb_host>:1026/v2/entities/Car1/attrs/speed/value Content-Type: text/plain ... 115 204 No Content … 15
- 16. Quick Usage Example: Car Speed Query (2) 16 200 OK Content-Type: text/plain ... 115.000000 GET <cb_host>:1026/v2/entities/Car1/attrs/speed/value Accept: text/plain
- 17. 201 Created ... Quick Usage Example: Room Create (1) POST <cb_host>:1026/v2/entities Content-Type: application/json ... { "id": "Room1", "type": "Room", "temperature": { "type": "Float", "value": 24 }, "pressure": { "type": "Integer", "value": 718 } } 17
- 18. 204 No Content … Quick Usage Example: Room Update (1) PATCH <cb_host>:1026/v2/entities/Room1/attrs Content-Type: application/json ... { "temperature“: { "type": "Float", "value": 25 }, "pressure": { "type": "Integer", "value": 720 } } 18
- 19. Quick Usage Example: Room Query (1) 19 200 OK Content-Type: application/json ... { "pressure": { "type": "Integer", "value": 720, "metadata": {} }, "temperature": { "type": "Float", "value": 25, "metadata": {} } } GET <cb_host>:1026/v2/entities/Room1/attrs
- 20. Quick Usage Example: Room Query (2) 20 200 OK Content-Type: application/json ... { "pressure": 720, "temperature": 25 } GET <cb_host>:1026/v2/entities/Room1/attrs?options=keyValues
- 21. 201 Created ... Quick Usage Example: Room Create (2) POST <cb_host>:1026/v2/entities Content-Type: application/json ... { "id": "Room2", "type": "Room", "temperature": { "type": "Float", "value": 29 }, "pressure": { "type": "Integer", "value": 730 } } 21
- 22. Quick Usage Example: Filters (1) 22 200 OK Content-Type: application/json ... [ { "id": "Room2", "pressure": 730, "temperature": 29, "type": "Room" } ] GET <cb_host>:1026/v2/entities?options=keyValues&q=temperature>27
- 23. Quick Usage Example: Filters (2) 23 200 OK Content-Type: application/json ... [ { "id": "Room1", "pressure": 720, "temperature": 25, "type": "Room" } ] GET <cb_host>:1026/v2/entities?options=keyValues&q=pressure==715..725 The full description of the Simple Query Language for filtering can be found in the NGSIv2 Specification document
- 24. Push data 24
- 25. Context Broker operations: push data • Context Consumers can subscribe to receive context information that satisfy certain conditions using the subscribe operation. Such subscriptions may have an expiration time. • The Context Broker notifies updates on context information to subscribed Context Consumers by invoking the notify operation they export subId = subscribeContext (consumer, expr, expiration) Context Consumer notify (subId, data/context) Context Broker Application 25
- 26. Quick Usage Example: Subscription POST <cb_host>:1026/v2/subscriptions Content-Type: application/json … { "subject": { "entities": [ { "id": "Room1", "type": "Room" } ], "condition": { "attrs": [ "temperature" ] } }, "notification": { "http": { "url": "http://<host>:<port>/publish" }, "attrs": [ "temperature" ] }, "expires": "2026-04-05T14:00:00.00Z" } 201 Created Location: /v2/subscriptions/51c0ac9ed714fb3b37d7d5a8 ... 26
- 27. POST /publish HTTP/1.1 Content-type: application/json; charset=utf-8 Ngsiv2-AttrsFormat: normalized … { "subscriptionId": "574d720dbef222abb860534a", "data": [ { "id": "Room1", "type": "Room", "temperature": { "type": "Float", "value": 19, "metadata": {} } } ] } Quick Usage Example: Notification 27 25 19
- 28. List existing subscriptions 28 200 OK Content-Type: application/json … [{ "id": " 51c0ac9ed714fb3b37d7d5a8 ", "expires": "2026-04-05T14:00:00.00Z", "status": "active", "subject": { "entities": [{ "id": "Room1", "type": "Room" }], "condition": { "attrs": ["temperature"] } }, "notification": { "timesSent": 3, "lastNotification": "2016-05-31T11:19:32.00Z", "lastSuccess": "2016-05-31T11:19:32.00Z", "attrs": ["temperature"], "attrsFormat": "normalized", "http": { "url": "http://localhost:1028/publish" } } }] The full description of the subscription object (including all its fields) can be found in the NGSIv2 Specification GET <cb_host>:1026/v2/subscriptions
- 30. Orion Context Broker batch operations 30 • Batch query and batch update • They are equivalent in functionality to previously described RESTful operations • All them use POST as verb and the /v2/op URL prefix, including operation parameters in the JSON payload • They implement extra functionality that cannot be achieved with RESTful operations, e.g. to create several entities with the same operation • They are not a substitute but a complement to RESTful operations
- 31. 201 Created ... Batch Operation Example: Create Several Rooms POST <cb_host>:1026/v2/op/update Conten-Type: application/json ... { "actionType": "APPEND", "entities": [ { "type": "Room", "id": "Room3", "temperature": { "value": 21.2, "type": "Float" }, "pressure": { "value": 722, "type": "Integer" } }, … 31 … { "type": "Room", "id": "Room4", "temperature": { "value": 31.8, "type": "Float" }, "pressure": { "value": 712, "type": "Integer" } } ] }
- 32. 32 Pagination Metadata Compound attribute/metadata values Type browsing Geo-location Query filters DateTime support Custom notifications Notification status Attribute/metadata filtering Special attribute/metadata Registrations & context providers Multitenancy Orion advanced functionality… next class! Creating & pulling data Pushing data Subscriptions & Notifications Batch operations
- 33. Comet 33
- 34. STH-COMET: Why? 34 ▪ The Context Broker only stores the latest attribute values: • Event-driven action-oriented paradigm ▪ The Short Time Historic adds memory into the equation: • Continuous improvement paradigm
- 35. STH-COMET: What? 35 ▪ Time series database: • Optimized to deal with values indexed in time • Raw data vs. Aggregated data • Basic aggregation concepts: □ Range □ Resolution □ Origin □ Offset
- 36. STH – Comet : How (birds-eye functioning: minimal) 36 update query (raw & aggregated) Client Orion Context Broker
- 37. Help project 37
- 38. Help project content 38 Context Broker IoT Agent Ultralight 2.0 STH - COMET MongoDB 7896 4041 1026 8666 Virtual Machine Instance ▪ Ansible and docker-compose file to deploy a Virtual Machine with Orion, IoT Agent Ultralight and Comet. https://github.com/flopezag/fiware-iot-hackathon ▪ Instruction to send data from sensor and recover them from Orion or Comet (data aggregation)
- 39. • The easy way – Orion User Manual: google for “Orion FIWARE manual” and use the first hit – Orion Catalogue page: google for “Orion FIWARE catalogue” and use the first hit • References – NGSIv2 Specification • http://fiware.github.io/specifications/ngsiv2/stable • http://fiware.github.io/specifications/ngsiv2/latest – NGSIv2 for NGSIv1 developers • http://bit.ly/ngsiv2-vs-ngsiv1 – Orion Catalogue: • http://catalogue.fiware.org/enablers/publishsubscribe-context-broker-orion-context- broker – Orion support though StackOverflow • Ask your questions using the “fiware-orion” tag • Look for existing questions at http://stackoverflow.com/questions/tagged/fiware-orion 39 Would you like to know more?
- 41. Thank you! http://fiware.org Follow @FIWARE on Twitter 41
- 42. Thank you! http://fiware.org Follow @FIWARE on Twitter
- 43. Backup slides
- 44. • Used by /v2/op/update (batch operation) • Conventional actionTypes – APPEND: append (or update if the attribute already exists) – UPDATE: update – DELETE: delete • Special actionTypes – APPEND_STRICT: strict append (returns error if some of the attributes to add already exists) – REPLACE: delete all the entity attributes, next append the ones in the update request Special update action types 44
- 45. NGSIv2 status (AKA the “NGSIv2 disclaimer”) • NGSIv2 is in “release candidate” status – By "release candidate" we mean that the specification is quite stable, but changes may occur with regard to new release candidates or the final version. In particular changes may be of two types: • Extensions to the functionality currently specified by this document. Note that in this case there isn't any risk of breaking backward compatibility on existing software implementations. • Slight modifications in the functionality currently specified by this document, as a consequence of ongoing discussions. Backward compatibility will be taken into account in this case, trying to minimize the impact on existing software implementations. In particular, only completely justified changes impacting backward compatibility will be allowed and "matter of taste" changes will not be allowed. 45
- 46. So… when should I use NGSIv1 or NGSIv2? • In general, it is always preferable to use NGSIv2 • However, you would need to use NGSIv1 if – You need register/discovery operations (context management availability functionality) • Not yet implemented in NGSIv2 (in roadmap) – Zero tolerance to changes in software interacting with Orion • Even if you use NGSIv1, you can still use NGSIv2 advanced functionality – See “Considerations on NGSIv1 and NGSIv2 coexistence” section at Orion manual • For a NGSIv1-based version of this presentation have a look to – http://bit.ly/fiware-orion-ngsiv1 46
Editor's Notes
- #6: Orion Context Broker is an implementation of a context information broker with persistent storage It implements OMA NGSI9/10 specification NGSI9 is about context information availability (i.e. sources of context information) management NGSI10 is about context information itself
- #39: - "7896" - "4041"