Orion Context Broker

https://fiware-orion.readthedocs.io/en/master/
Admin
Orion Context Broker is a C++ implementation of the NGSIv2 REST API binding within the FIWARE...
Tokens:168,327
Snippets:1,037
Trust Score:8.3
Update:1 week ago
Show doc for...
Tokens:
Raw
### Install libmicrohttpd from source

Source: https://fiware-orion.readthedocs.io/en/master/admin/build_source.html

Downloads and installs libmicrohttpd 1.0.2 with a recommended minimal configuration. The ./configure command shows the recommended build configuration to get minimum library footprint.

```bash
wget https://ftp.gnu.org/gnu/libmicrohttpd/libmicrohttpd-1.0.2.tar.gz
tar xvf libmicrohttpd-1.0.2.tar.gz
cd libmicrohttpd-1.0.2
./configure --disable-messages --disable-postprocessor --disable-dauth
make
sudo make install  # installation puts .h files in /usr/local/include and library in /usr/local/lib
sudo ldconfig      # just in case... it doesn't hurt :)

```

--------------------------------

### Start Orion Context Broker

Source: https://fiware-orion.readthedocs.io/en/master/user/walkthrough_apiv2.html

Starts the Orion Context Broker as root or with sudo. Assumes the broker is installed and the database is empty.

```bash
/etc/init.d/contextBroker start

```

--------------------------------

### Install the Orion Context Broker binary

Source: https://fiware-orion.readthedocs.io/en/master/admin/build_source.html

Installs the broker binary. INSTALL_DIR sets the installation prefix (default /usr), placing the broker in $INSTALL_DIR/bin.

```bash
sudo make install INSTALL_DIR=/usr

```

--------------------------------

### Get the Orion Context Broker source code

Source: https://fiware-orion.readthedocs.io/en/master/admin/build_source.html

Installs git and clones the fiware-orion repository.

```bash
sudo apt-get install git
git clone https://github.com/telefonicaid/fiware-orion

```

--------------------------------

### Install Context Broker

Source: https://fiware-orion.readthedocs.io/en/master/admin/extra/ha.html

Creates the FIWARE repository file and installs the contextBroker package.

```bash
$ nano /etc/yum.repos.d/fiware.repo
[fiware]
name=Fiware Repository
baseurl=http://repositories.lab.fiware.org/repo/rpm/$releasever
gpgcheck=0
enabled=1
$ yum install contextBroker
```

--------------------------------

### Start Context Broker

Source: https://fiware-orion.readthedocs.io/en/master/admin/extra/ha.html

Starts the Context Broker service.

```bash
$ /etc/init.d/contextBroker start
```

--------------------------------

### Pagination example with limit and offset

Source: https://fiware-orion.readthedocs.io/en/master/orion-api.html

Shows how to retrieve a large set of entities in pages of 100 using limit and offset. The first request includes options=count to get the total count via the Fiware-Total-Count header. Subsequent requests use offset to fetch the next pages.

```http
GET /v2/entities?limit=100&options=count
...
(The first 100 elements are returned, along with the `Fiware-Total-Count: 322`
header, which makes the client aware of how many entities there are in total and,
therefore, the number of subsequent queries to be done)

GET /v2/entities?offset=100&limit=100
...
(Entities from 101 to 200)

GET /v2/entities?offset=200&limit=100
...
(Entities from 201 to 300)

GET /v2/entities?offset=300&limit=100
...
(Entities from 301 to 222)

```

--------------------------------

### Install Google Test/Mock from source

Source: https://fiware-orion.readthedocs.io/en/master/admin/build_source.html

Downloads and installs gmock 1.5.0 from a Fedora mirror because the original URL is no longer working.

```bash
wget https://src.fedoraproject.org/repo/pkgs/gmock/gmock-1.5.0.tar.bz2/d738cfee341ad10ce0d7a0cc4209dd5e/gmock-1.5.0.tar.bz2
tar xfvj gmock-1.5.0.tar.bz2
cd gmock-1.5.0
./configure

```

--------------------------------

### List Registrations Response Example

Source: https://fiware-orion.readthedocs.io/en/master/orion-api.html

Example JSON array returned by GET /v2/registrations. Each object represents a registration with fields such as id, description, dataProvided, provider, expires, status, and forwardingInformation.

```json
[
  {
    "id": "62aa3d3ac734067e6f0d0871",
    "description": "Example Context Source",
    "dataProvided": {
      "entities": [
        {
          "id": "Bcn_Welt",
          "type": "Room"
        }
      ],
      "attrs": [
        "temperature"
      ]
    },
    "provider": {
      "http": {
        "url": "http://contextsource.example.org"
      },
      "supportedForwardingMode": "all"
    },
    "expires": "2017-10-31T12:00:00",
    "status": "active",
    "forwardingInformation": {
      "timesSent": 12,
      "lastForwarding": "2017-10-06T16:00:00.00Z",
      "lastSuccess": "2017-10-06T16:00:00.00Z",
      "lastFailure": "2017-10-05T16:00:00.00Z"
    }
  }
]
```

--------------------------------

### Example of expression evaluation with evalPriority

Source: https://fiware-orion.readthedocs.io/en/master/orion-api.html

Shows the same configuration as the previous example but with evalPriority metadata set on A to ensure A is evaluated before B, guaranteeing B gets the desired value.

```json
{
  "httpCustom": {
    ...
    "ngsi": {
      "A": {
        "value": "${16|sqrt}",
        "type": "Calculated",
        "metadata": {
          "evalPriority": {
            "value": 1,
            "type": "Number"
          }
        }
      },
      "B": {
        "value": "${A/100}",
        "type": "Calculated"
      }
    },
    "attrs": [ "B" ]
  }
}
```

--------------------------------

### Install Monit

Source: https://fiware-orion.readthedocs.io/en/master/admin/watchdog.html

Installs the Monit monitoring tool using apt-get.

```bash
sudo apt-get install monit

```

--------------------------------

### Install build tools (make, cmake, g++)

Source: https://fiware-orion.readthedocs.io/en/master/admin/build_source.html

Installs the essential build tools needed to compile the Orion Context Broker.

```bash
sudo apt-get install make cmake g++

```

--------------------------------

### Install Mongo C Driver from source

Source: https://fiware-orion.readthedocs.io/en/master/admin/build_source.html

Downloads and installs the Mongo C driver version 2.2.1 from source.

```bash
wget https://github.com/mongodb/mongo-c-driver/releases/download/2.2.1/mongo-c-driver-2.2.1.tar.gz
tar xfvz mongo-c-driver-2.2.1.tar.gz
cd mongo-c-driver-2.2.1
mkdir cmake-build
cd cmake-build
cmake ..
make
sudo make install

```

--------------------------------

### Start MongoDB service

Source: https://fiware-orion.readthedocs.io/en/master/admin/extra/ha.html

Starts the MongoDB service on each server.

```bash
service mongod start
```

--------------------------------

### Install rapidjson from source

Source: https://fiware-orion.readthedocs.io/en/master/admin/build_source.html

Downloads and installs rapidjson 1.1.0, including a sed workaround for a problematic line in document.h when using GCC14+.

```bash
wget https://github.com/miloyip/rapidjson/archive/v1.1.0.tar.gz
tar xfvz v1.1.0.tar.gz
sudo mv rapidjson-1.1.0/include/rapidjson/ /usr/local/include
# Next line is to comment a problematic line in document.h when GCC14+ is used
# (it should be solved by rapidjson, see https://github.com/Tencent/rapidjson/issues/2277)
sudo sed -i 's/^.*GenericStringRef& operator=(const GenericStringRef& rhs).*$/\/\/&/' /usr/local/include/rapidjson/document.h

```

--------------------------------

### Monit start script

Source: https://fiware-orion.readthedocs.io/en/master/admin/watchdog.html

Starts Monit with a 10-second cycle duration using the specified configuration and pid file.

```bash
monit -v -c /home/orion/monit_CB/monitBROKER.conf -d 10 -p /var/log/contextBroker/monit.pid

```

--------------------------------

### Install required libraries (Debian 13)

Source: https://fiware-orion.readthedocs.io/en/master/admin/build_source.html

Installs the required libraries for building the broker, except those built from source.

```bash
sudo apt-get install libssl-dev libcurl4-openssl-dev libboost-dev libboost-regex-dev libboost-filesystem-dev libboost-thread-dev uuid-dev libgnutls28-dev libsasl2-dev libgcrypt-dev librdkafka-dev zlib1g-dev libzstd-dev liblz4-dev

```

--------------------------------

### Install mosquitto from source

Source: https://fiware-orion.readthedocs.io/en/master/admin/build_source.html

Downloads and installs mosquitto 2.0.22, modifying config.mk to disable cjson and static/shared library settings as needed.

```bash
wget https://mosquitto.org/files/source/mosquitto-2.0.22.tar.gz
tar xvf mosquitto-2.0.22.tar.gz
cd mosquitto-2.0.22
sed -i 's/WITH_CJSON:=yes/WITH_CJSON:=no/g' config.mk
sed -i 's/WITH_STATIC_LIBRARIES:=no/WITH_STATIC_LIBRARIES:=yes/g' config.mk
sed -i 's/WITH_SHARED_LIBRARIES:=yes/WITH_SHARED_LIBRARIES:=no/g' config.mk
make
sudo make install  # installation puts .h files in /usr/local/include and library in /usr/local/lib
sudo ldconfig      # Update /etc/ld.so.cache with the new library files in /usr/local/lib

```

--------------------------------

### Set ownership and permissions for start script

Source: https://fiware-orion.readthedocs.io/en/master/admin/watchdog.html

Makes root the owner and sets execution permissions for the start script.

```bash
sudo chown root:root start_monit_BROKER.sh
sudo chmod a+x start_monit_BROKER.sh

```

--------------------------------

### Install additional tools for functional and valgrind tests

Source: https://fiware-orion.readthedocs.io/en/master/admin/build_source.html

Install required system packages for functional and valgrind tests.

```bash
sudo apt-get install curl netcat-traditional valgrind bc python3 python3-pip mosquitto
```

--------------------------------

### Install HA Proxy

Source: https://fiware-orion.readthedocs.io/en/master/admin/extra/ha.html

Installs HA Proxy using apt-get.

```bash
$ sudo apt-get install haproxy
```

--------------------------------

### Install lcov for coverage

Source: https://fiware-orion.readthedocs.io/en/master/admin/build_source.html

Install the lcov tool and xsltproc for generating coverage reports.

```bash
sudo apt-get install lcov xsltproc
```

--------------------------------

### Filter entities by id pattern with GET /v2/entities?idPattern=^Room[2-5]

Source: https://fiware-orion.readthedocs.io/en/master/user/walkthrough_apiv2.html

Filters entities using the 'idPattern' URL parameter with a regular expression. The example matches entity IDs starting with 'Room' followed by a digit from 2 to 5, retrieving Room2. The -g flag in curl avoids problems with brackets in the pattern.

```bash
curl localhost:1026/v2/entities?idPattern=^Room[2-5] -g -s -S -H 'Accept: application/json' | python -mjson.tool

```

--------------------------------

### Boot-time INFO traces

Source: https://fiware-orion.readthedocs.io/en/master/admin/logs.html

Shows the INFO traces emitted at boot time, including the start command line, the broker running message, MongoDB connection, and startup completion.

```text
time=2021-03-09T16:14:36.055Z | lvl=INFO | corr=N/A | trans=N/A | from=N/A | srv=N/A | subsrv=N/A | comp=Orion | op=contextBroker.cpp[1000]:main | msg=start command line <contextBroker -fg -logLevel INFO>
time=2021-03-09T16:14:36.055Z | lvl=INFO | corr=N/A | trans=N/A | from=N/A | srv=N/A | subsrv=N/A | comp=Orion | op=contextBroker.cpp[1068]:main | msg=Orion Context Broker is running
time=2021-03-09T16:14:36.083Z | lvl=INFO | corr=N/A | trans=N/A | from=N/A | srv=N/A | subsrv=N/A | comp=Orion | op=mongoConnectionPool.cpp[488]:mongoConnectionPoolInit | msg=Connected to mongodb://localhost/?connectTimeoutMS=10000 (dbName: orion, poolsize: 10)
time=2021-03-09T16:14:36.086Z | lvl=INFO | corr=N/A | trans=N/A | from=N/A | srv=N/A | subsrv=N/A | comp=Orion | op=contextBroker.cpp[1194]:main | msg=Startup completed
```

--------------------------------

### URL-Encoded Entity ID in GET Request

Source: https://fiware-orion.readthedocs.io/en/master/orion-api.html

Example GET request using a URL-encoded entity ID to avoid forbidden characters. The '%25' encodes the '%' character itself, as required for fields in the API URL.

```http
GET /v2/entities/E%253C01%253E

```

--------------------------------

### Install Kafka client CLI

Source: https://fiware-orion.readthedocs.io/en/master/admin/build_source.html

Install the Kafka client CLI by downloading and extracting the Kafka tarball, then adding its bin directory to your PATH.

```bash
sudo apt-get install openjdk-21-jre-headless wget https://dlcdn.apache.org/kafka/4.3.1/kafka_2.13-4.3.1.tgz tar xvf kafka_2.13-4.3.1.tgz # Add kafka_2.13-4.3.1/bin to your PATH (e.g. editing ~/.bashrc)
```

--------------------------------

### GET /v2/registrations/{registrationId} - Example Response Payload

Source: https://fiware-orion.readthedocs.io/en/master/orion-api.html

Example JSON response payload for retrieving a registration. Shows the registration representation format including id, description, dataProvided, provider, expires, status, and forwardingInformation.

```json
{
      "id": "62aa3d3ac734067e6f0d0871",
      "description": "Example Context Source",
      "dataProvided": {
        "entities": [
          {
            "id": "Bcn_Welt",
            "type": "Room"
          }
        ],
        "attrs": [
          "temperature"
        ]
      },
      "provider": {
        "http": {
          "url": "http://contextsource.example.org"
        },
        "supportedForwardingMode": "all"
      },
      "expires": "2017-10-31T12:00:00",
      "status": "active",
      "forwardingInformation": {
        "timesSent": 12,
        "lastForwarding": "2017-10-06T16:00:00.00Z",
        "lastFailure": "2017-10-06T16:00:00.00Z",
        "lastSuccess": "2017-10-05T18:25:00.00Z",
      }
}
```

--------------------------------

### Prepare test harness environment

Source: https://fiware-orion.readthedocs.io/en/master/admin/build_source.html

Set up the test harness environment: install accumulator-server.py, set environment variables, create a virtualenv, and install required Python packages.

```bash
mkdir ~/bin
export PATH=~/bin:$PATH
make install_scripts INSTALL_DIR=~
. scripts/testEnv.sh
python3 -m venv /opt/ft_env   # or 'virtualenv /opt/ft_env --python=/usr/bin/python3' in some systems
. /opt/ft_env/bin/activate
pip install Flask==2.0.2 Werkzeug==2.0.2 paho-mqtt==1.6.1 amqtt==0.11.0b1 setuptools==80.9.0 confluent-kafka==2.11.0
```

--------------------------------

### Example response payload for GET attribute data

Source: https://fiware-orion.readthedocs.io/en/master/orion-api.html

Shows the JSON object returned by the endpoint, containing the attribute value, type, and metadata.

```json
{
  "value": 21.7,
  "type": "Number",
  "metadata": {}
}
```

--------------------------------

### Log format example lines

Source: https://fiware-orion.readthedocs.io/en/master/admin/logs.html

Shows the key-value log format with pipe separators, including startup, request, and shutdown traces.

```text
time=2020-10-26T09:45:17.225Z | lvl=INFO | corr=N/A | trans=N/A | from=N/A | srv=N/A | subsrv=N/A | comp=Orion | op=contextBroker.cpp[986]:main | msg=start command line <contextBroker -fg -logLevel INFO>
time=2020-10-26T09:45:17.225Z | lvl=INFO | corr=N/A | trans=N/A | from=N/A | srv=N/A | subsrv=N/A | comp=Orion | op=contextBroker.cpp[873]:logEnvVars | msg=env var ORION_PORT (-port): 1026
time=2020-10-26T09:45:17.225Z | lvl=INFO | corr=N/A | trans=N/A | from=N/A | srv=N/A | subsrv=N/A | comp=Orion | op=contextBroker.cpp[1054]:main | msg=Orion Context Broker is running
time=2020-10-26T09:45:17.301Z | lvl=INFO | corr=N/A | trans=N/A | from=N/A | srv=N/A | subsrv=N/A | comp=Orion | op=MongoGlobal.cpp[247]:mongoInit | msg=Connected to mongo at localhost/orion (poolsize: 10)
time=2020-10-26T09:45:17.304Z | lvl=INFO | corr=N/A | trans=N/A | from=N/A | srv=N/A | subsrv=N/A | comp=Orion | op=contextBroker.cpp[1180]:main | msg=Startup completed
...
time=2020-10-26T10:27:02.619Z | lvl=INFO | corr=c99e4592-1775-11eb-ad30-000c29df7908 | trans=1603707992-318-00000000001 | from=0.0.0.0 | srv=s1 | subsrv=/A | comp=Orion | op=logTracing.cpp[79]:logInfoRequestWithoutPayload | msg=Request received: GET /v2/entities?type=Device, response code: 200
...
time=2020-10-26T10:32:41.724Z | lvl=INFO | corr=93bdc5b4-1776-11eb-954d-000c29df7908 | trans=1603708355-537-00000000002 | from=0.0.0.0 | srv=s1 | subsrv=/A | comp=Orion | op=logTracing.cpp[130]:logInfoRequestWithPayload | msg=Request received: POST /v2/entities, request payload (34 bytes): {  "id": "Room1",  "type": "Room"}, response code: 201
...
time=2020-10-26T16:44:53.541Z | lvl=INFO | corr=N/A | trans=N/A | corr=N/A | from=N/A | srv=N/A | subsrv=N/A | comp=Orion | op=contextBroker.cpp[968]:sigHandler | msg=Signal Handler (caught signal 2)
time=2020-10-26T16:44:53.541Z | lvl=INFO | corr=N/A | trans=N/A | corr=N/A | from=N/A | srv=N/A | subsrv=N/A | comp=Orion | op=contextBroker.cpp[974]:sigHandler | msg=Orion context broker exiting due to receiving a signal
```

--------------------------------

### List Subscriptions Response Example (GET /v2/subscriptions)

Source: https://fiware-orion.readthedocs.io/en/master/orion-api.html

Example JSON response payload for listing subscriptions. The payload is an array of subscription objects, each following the JSON subscription representation format. Includes fields like id, description, subject, notification, expires, status, and throttling.

```json
[
  {
    "id": "62aa3d3ac734067e6f0d0871",
    "description": "One subscription to rule them all",
    "subject": {                    
      "entities": [
        {
          "id": "Bcn_Welt",
          "type": "Room"
        }
      ],
      "condition": {
          "attrs": [ "temperature " ],
          "expression": {
            "q": "temperature>40"
          }
      }
    },
    "notification": {
      "httpCustom": {
        "url": "http://localhost:1234",
        "headers": {
          "X-MyHeader": "foo"
        },
        "qs": {
          "authToken": "bar"
        }
      },
      "attrsFormat": "keyValues",
      "attrs": ["temperature", "humidity"],
      "timesSent": 12,
      "lastNotification": "2015-10-05T16:00:00.00Z",
      "lastFailure": "2015-10-06T16:00:00.00Z"
    },
    "expires": "2025-04-05T14:00:00.00Z",
    "status": "active",
    "throttling": 5
  }
]
```

--------------------------------

### Log config response JSON pattern

Source: https://fiware-orion.readthedocs.io/en/master/admin/management_api.html

Example JSON response returned by the GET /admin/log request. Shows the structure with infoPayloadMaxSize, level, lineMaxSize, and deprecate.

```json
{
    "infoPayloadMaxSize": 5120,
    "level": "DEBUG",
    "lineMaxSize": 32768,
    "deprecate": false
}

```

--------------------------------

### Show brief usage

Source: https://fiware-orion.readthedocs.io/en/master/admin/cli.html

Displays a list of available options in brief format.

```bash
contextBroker -u
```

--------------------------------

### GET /v2/entities?offset=54882 - Error Response

Source: https://fiware-orion.readthedocs.io/en/master/admin/database_admin.html

Example of the error response returned when a sorting operation exceeds the maximum RAM. The error message suggests creating an index.

```json
GET /v2/entities?offset=54882

{
    "description": "Sort operation used more than the maximum RAM. You should create an index. Check the Database Administration section in Orion documentation.",
    "error": "InternalServerError"
}
```

--------------------------------

### trim transformation example

Source: https://fiware-orion.readthedocs.io/en/master/orion-api.html

Removes starting and trailing whitespaces. With context {"c": "  foo  bar  "}, c|trim results in "foo  bar".

```plaintext
c|trim
```

```plaintext
foo  bar
```

--------------------------------

### Filter entities by type with GET /v2/entities?type=Room

Source: https://fiware-orion.readthedocs.io/en/master/user/walkthrough_apiv2.html

Filters entities by type using the 'type' URL parameter. In this example, it retrieves all entities with type 'Room', which returns both Room1 and Room2.

```bash
curl localhost:1026/v2/entities?type=Room -s -S  -H 'Accept: application/json' | python -mjson.tool

```

--------------------------------

### Example of summary traces output

Source: https://fiware-orion.readthedocs.io/en/master/admin/logs.html

Shows the six summary traces printed each reporting period when -logSummary is enabled. The lines are abbreviated for clarity. Each line provides counts for the current period and totals since Orion started.

```plaintext
time=... | lvl=SUMMARY | ... Transactions: 2345 (new: 45)
time=... | lvl=SUMMARY | ... DB status: ok, raised: (total: 0, new: 0), released: (total: 0, new: 0)
time=... | lvl=SUMMARY | ... Notification failure active alarms: 0, raised: (total: 0, new: 0), released: (total: 0, new: 0)
time=... | lvl=SUMMARY | ... Forwarding failure active alarms: 0, raised: (total: 0, new: 0), released: (total: 0, new: 0)
time=... | lvl=SUMMARY | ... MQTT connection failure active alarms: 0, raised: (total: 0, new: 0), released: (total: 0, new: 0)
time=... | lvl=SUMMARY | ... Bad input active alarms: 5, raised: (total: 12, new: 1), released: (total: 7, new: 2)
```

--------------------------------

### Build the Orion Context Broker

Source: https://fiware-orion.readthedocs.io/en/master/admin/build_source.html

Builds the broker from source.

```bash
cd fiware-orion
make

```

--------------------------------

### Semaphore listing response JSON

Source: https://fiware-orion.readthedocs.io/en/master/admin/management_api.html

Example JSON response from GET /admin/sem showing the status of each semaphore. Includes alarmMgr, connectionContext, connectionEndpoints, dbConnection, dbConnectionPool, logMsg, metrics, mqttMgr, kafkaMgr, request, subCache, timeStat, and transaction.

```json
{
    "alarmMgr": {
        "status": "free"
    },
    "connectionContext": {
        "status": "free"
    },
    "connectionEndpoints": {
        "status": "free"
    },
    "dbConnection": {
        "status": "free"
    },
    "dbConnectionPool": {
        "status": "free"
    },
    "logMsg": {
        "status": "free"
    },
    "metrics": {
        "status": "free"
     },
    "mqttMgr": {
        "status": "free"
    },
    "kafkaMgr": {
        "status": "free"
    },
    "request": {
        "status": "free"
    },
    "subCache": {
        "status": "free"
    },
    "timeStat": {
        "status": "free"
    },
    "transaction": {
        "status": "free"
    }
}

```

--------------------------------

### Successful Response for GET /v2/entities/{entityId}/attrs

Source: https://fiware-orion.readthedocs.io/en/master/orion-api.html

Returned when the entity is found. The payload is a JSON object representing the entity attributes, omitting the id and type fields. The example shows temperature, humidity, and location attributes with their values and metadata.

```json
{
  "temperature": {
    "value": 21.7,
    "type": "Number"
  },
  "humidity": {
    "value": 60,
    "type": "Number"
  },
  "location": {
    "value": {
      "type": "Point",
      "coordinates": [2.1864475, 41.3763726]
    },
    "type": "geo:json",
    "metadata": {
      "crs": {
        "value": "WGS84",
        "type": "Text"
      }
    }
  }
}
```

--------------------------------

### Example of reserved queues/pools for two services

Source: https://fiware-orion.readthedocs.io/en/master/admin/perf_tuning.html

Example configuration with two services (serv1 and serv2) having their own queues and worker pools. Notifications for serv1 use q1/n1, for serv2 use q2/n2, and others use q/n.

```text
-notificationMode threadpool:q:n,serv1:q1:n1,serv2:q2:n2

```

--------------------------------

### Run contextBroker

Source: https://fiware-orion.readthedocs.io/en/master/admin/cli.html

Starts the broker in the background by default. Use signals to stop it.

```bash
contextBroker
```

--------------------------------

### Filter entities by attribute with GET /v2/entities?q=temperature>22

Source: https://fiware-orion.readthedocs.io/en/master/user/walkthrough_apiv2.html

Filters entities using attribute filters with the 'q' URL parameter. The example retrieves entities whose temperature is above 22, returning Room1. The query uses the Simple Query Language syntax.

```bash
curl 'localhost:1026/v2/entities?q=temperature>22' -s -S  -H 'Accept: application/json' | python -mjson.tool

```

--------------------------------

### Kafka notification subscription configuration

Source: https://fiware-orion.readthedocs.io/en/master/user/kafka_notifications.html

Example of a notification object using `kafka` instead of `http`. The `url` must start with `kafka://` and contain only host and port. The `topic` specifies the Kafka topic. Optional fields include `user`, `passwd`, `saslMechanism`, and `securityProtocol` for SASL authentication.

```json
...
"notification": {
  "kafka": {
    "url": "kafka://broker1:9092,broker2:9092,broker3:9092",
    "topic": "sub1"
  }
}
...
```

--------------------------------

### Check curl installation with which curl

Source: https://fiware-orion.readthedocs.io/en/master/user/walkthrough_apiv2.html

Check if curl is installed on your system.

```bash
which curl

```

--------------------------------

### Run Monit

Source: https://fiware-orion.readthedocs.io/en/master/admin/watchdog.html

Changes to the Monit directory and runs the start script to launch Monit.

```bash
cd /home/orion/monit_CB
sudo ./start_monit_BROKER.sh

```
Tokens:
Raw