IoTDB Sink

The IoTDB sink writes data into Apache IoTDB by using the native Thrift RPC client. It supports both the tree model and the table model.

Compile the Plugin

In the rekuiper source code root directory, run the following command:

go build -trimpath --buildmode=plugin -o plugins/sinks/Iotdb.so extensions/sinks/iotdb/*.go

Properties

Connection Properties

Property name	Optional	Default value	Description
addr	false	127.0.0.1:6667	IoTDB server address in host:port format.
username	true	root	The username for authentication.
password	true	root	The password for authentication.
nodeUrls	true	[]	Cluster node URLs. When set, overrides the addr property.
timeout	true	5000	Connection timeout in milliseconds.
poolSize	true	3	The size of the connection pool.

Model Selection

Property name	Optional	Default value	Description
model	false	tree	The data model to use: tree or table.

Tree Model Properties

The following properties apply when model is set to tree:

Property name	Optional	Default value	Description
device	true	""	The device path, such as root.sg1.dev1. Required for the tree model.
isAligned	true	false	Controls whether to use aligned time series.

Table Model Properties

The following properties apply when model is set to table:

Property name	Optional	Default value	Description
database	true	""	The database name. The root. prefix is removed automatically. Required for the table model.
table	true	""	The target table name. Required for the table model.
columnCategories	true	[]	Column categories mapped one-to-one to measurements: TAG, FIELD, or ATTRIBUTE. Required for the table model.

Data Mapping Properties

Property name	Optional	Default value	Description
measurements	false	[]	List of measurement or column names.
dataTypes	false	[]	IoTDB data types mapped one-to-one to measurements: INT32, INT64, FLOAT, DOUBLE, BOOLEAN, TEXT, STRING, or TIMESTAMP.
tsFieldName	true	""	Field name containing the timestamp in milliseconds. If omitted, rekuiper uses the current time. When set, every record must contain this field.
batchSize	true	10	The number of rows written per tablet batch.

Other common sink properties, including batch settings, are supported. Refer to sink common properties for more information.

Sample Usage

Tree Model Example

The following rule selects temperature values greater than 50 and writes data to IoTDB using the tree model:

{
  "id": "iotdb_tree",
  "sql": "SELECT * from demo_stream where temperature > 50",
  "actions": [
    {
      "log": {},
      "iotdb": {
        "addr": "127.0.0.1:6667",
        "username": "root",
        "password": "root",
        "model": "tree",
        "device": "root.sg1.d1",
        "measurements": ["temperature", "humidity"],
        "dataTypes": ["FLOAT", "FLOAT"],
        "tsFieldName": "ts",
        "batchSize": 10
      }
    }
  ]
}

Table Model Example

The following rule selects temperature values greater than 50 and writes data to IoTDB using the table model:

{
  "id": "iotdb_table",
  "sql": "SELECT * from demo_stream where temperature > 50",
  "actions": [
    {
      "log": {},
      "iotdb": {
        "addr": "127.0.0.1:6667",
        "username": "root",
        "password": "root",
        "model": "table",
        "database": "iot_data",
        "table": "sensor_data",
        "measurements": ["device_id", "temperature", "humidity"],
        "dataTypes": ["STRING", "FLOAT", "FLOAT"],
        "columnCategories": ["TAG", "FIELD", "FIELD"],
        "tsFieldName": "ts",
        "batchSize": 10
      }
    }
  ]
}

Data Types

The following IoTDB data types are supported in the dataTypes property:

Data type	Description
INT32	32-bit signed integer
INT64	64-bit signed integer
FLOAT	Single-precision floating point
DOUBLE	Double-precision floating point
BOOLEAN	Boolean value (true or false)
TEXT	Text string (legacy IoTDB type)
STRING	String value
TIMESTAMP	Timestamp value in milliseconds

Notes

• Apache IoTDB uses the Thrift RPC protocol on TCP port 6667 by default.
• For the table model, rekuiper automatically creates the database if it does not exist.
• The root. prefix in the database property is stripped automatically in the table model.
• Missing record fields are written to IoTDB as null values.