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## RESTful Services  
IoTDB's RESTful services can be used for query, write, and management operations, using the OpenAPI standard to define interfaces and generate frameworks.

### Enable RESTful Services

RESTful services are disabled by default.

* Developer

  Find the `IoTDBrestServiceConfig` class under `org.apache.iotdb.db.conf.rest` in the sever module, and modify `enableRestService=true`.

* User

  Find the `conf/iotdb.rest.properties` file under the IoTDB installation directory and set `enable_rest_service` to `true` to enable the module.

  ```properties
  enable_rest_service=true
  ```

### Authentication
Except the liveness probe API `/ping`, RESTful services use the basic authentication. Each URL request needs to carry `'Authorization': 'Basic ' + base64.encode(username + ':' + password)`.

The username used in the following examples is: `root`, and password is: `root`.

And the authorization header is

```
Authorization: Basic cm9vdDpyb2901
```

- If a user authorized with incorrect username or password, the following error is returned:

  HTTP Status Code：`401`

  HTTP response body:
    ```json
    {
      "code": 600,
      "message": "WRONG_LOGIN_PASSWORD_ERROR"
    }
    ```

- If the `Authorization` header is missing，the following error is returned:

  HTTP Status Code：`401`

  HTTP response body:
    ```json
    {
      "code": 603,
      "message": "UNINITIALIZED_AUTH_ERROR"
    }
    ```

### Interface

#### ping

The `/ping` API can be used for service liveness probing.

Request method: `GET`

Request path: http://ip:port/ping

The user name used in the example is: root, password: root

Example request: 

```shell
$ curl http://127.0.0.1:18080/ping
```

Response status codes:

- `200`: The service is alive.
- `503`: The service cannot accept any requests now.

Response parameters:

|parameter name  |parameter type |parameter describe|
|:--- | :--- | :---|
|code | integer |  status code |
| message  |  string | message |

Sample response:

- With HTTP status code `200`:

  ```json
  {
    "code": 200,
    "message": "SUCCESS_STATUS"
  }
  ```

- With HTTP status code `503`:

  ```json
  {
    "code": 500,
    "message": "thrift service is unavailable"
  }
  ```

> `/ping` can be accessed without authorization.

#### query

The query interface can be used to handle data queries and metadata queries.

Request method: `POST`

Request header: `application/json`

Request path: http://ip:port/rest/v1/query

Parameter Description:

| parameter name | parameter type | required | parameter description                                        |
|----------------| -------------- | -------- | ------------------------------------------------------------ |
| sql            | string         | yes      |                                                              |
| rowLimit      | integer        | no       | The maximum number of rows in the result set that can be returned by a query. <br />If this parameter is not set, the `rest_query_default_row_size_limit` of the configuration file will be used as the default value. <br /> When the number of rows in the returned result set exceeds the limit, the status code `411` will be returned. |

Response parameters:

| parameter name | parameter type | parameter description                                        |
|----------------| -------------- | ------------------------------------------------------------ |
| expressions    | array          | Array of result set column names for data query, `null` for metadata query |
| columnNames   | array          | Array of column names for metadata query result set, `null` for data query |
| timestamps     | array          | Timestamp column, `null` for metadata query                  |
| values         | array          | A two-dimensional array, the first dimension has the same length as the result set column name array, and the second dimension array represents a column of the result set |

**Examples:**

Tip: Statements like `select * from root.xx.**` are not recommended because those statements may cause OOM.

**Expression query**

```shell
curl -H "Content-Type:application/json" -H "Authorization:Basic cm9vdDpyb290" -X POST --data '{"sql":"select s3, s4, s3 + 1 from root.sg27 limit 2"}' http://127.0.0.1:18080/rest/v1/query
````

```json
{
  "expressions": [
    "root.sg27.s3",
    "root.sg27.s4",
    "root.sg27.s3 + 1"
  ],
  "columnNames": null,
  "timestamps": [
    1635232143960,
    1635232153960
  ],
  "values": [
    [
      11,
      null
    ],
    [
      false,
      true
    ],
    [
      12.0,
      null
    ]
  ]
}
```

**Show child paths**

```shell
curl -H "Content-Type:application/json" -H "Authorization:Basic cm9vdDpyb290" -X POST --data '{"sql":"show child paths root"}' http://127.0.0.1:18080/rest/v1/query
```

```json
{
  "expressions": null,
  "columnNames": [
    "child paths"
  ],
  "timestamps": null,
  "values": [
    [
      "root.sg27",
      "root.sg28"
    ]
  ]
}
```

**Show child nodes**

```shell
curl -H "Content-Type:application/json" -H "Authorization:Basic cm9vdDpyb290" -X POST --data '{"sql":"show child nodes root"}' http://127.0.0.1:18080/rest/v1/query
```

```json
{
  "expressions": null,
  "columnNames": [
    "child nodes"
  ],
  "timestamps": null,
  "values": [
    [
      "sg27",
      "sg28"
    ]
  ]
}
```

**Show all ttl**

```shell
curl -H "Content-Type:application/json" -H "Authorization:Basic cm9vdDpyb290" -X POST --data '{"sql":"show all ttl"}' http://127.0.0.1:18080/rest/v1/query
```

```json
{
  "expressions": null,
  "columnNames": [
    "database",
    "ttl"
  ],
  "timestamps": null,
  "values": [
    [
      "root.sg27",
      "root.sg28"
    ],
    [
      null,
      null
    ]
  ]
}
```

**Show ttl**

```shell
curl -H "Content-Type:application/json" -H "Authorization:Basic cm9vdDpyb290" -X POST --data '{"sql":"show ttl on root.sg27"}' http://127.0.0.1:18080/rest/v1/query
```

```json
{
  "expressions": null,
  "columnNames": [
    "database",
    "ttl"
  ],
  "timestamps": null,
  "values": [
    [
      "root.sg27"
    ],
    [
      null
    ]
  ]
}
```

**Show functions**

```shell
curl -H "Content-Type:application/json" -H "Authorization:Basic cm9vdDpyb290" -X POST --data '{"sql":"show functions"}' http://127.0.0.1:18080/rest/v1/query
```

```json
{
  "expressions": null,
  "columnNames": [
    "function name",
    "function type",
    "class name (UDF)"
  ],
  "timestamps": null,
  "values": [
    [
      "ABS",
      "ACOS",
      "ASIN",
       ...
    ],
    [
      "built-in UDTF",
      "built-in UDTF",
      "built-in UDTF",
      ...
    ],
    [
      "org.apache.iotdb.db.query.udf.builtin.UDTFAbs",
      "org.apache.iotdb.db.query.udf.builtin.UDTFAcos",
      "org.apache.iotdb.db.query.udf.builtin.UDTFAsin",
      ...
    ]
  ]
}
```

**Show timeseries**

```shell
curl -H "Content-Type:application/json" -H "Authorization:Basic cm9vdDpyb290" -X POST --data '{"sql":"show timeseries"}' http://127.0.0.1:18080/rest/v1/query
```

```json
{
  "expressions": null,
  "columnNames": [
    "timeseries",
    "alias",
    "database",
    "dataType",
    "encoding",
    "compression",
    "tags",
    "attributes"
  ],
  "timestamps": null,
  "values": [
    [
      "root.sg27.s3",
      "root.sg27.s4",
      "root.sg28.s3",
      "root.sg28.s4"
    ],
    [
      null,
      null,
      null,
      null
    ],
    [
      "root.sg27",
      "root.sg27",
      "root.sg28",
      "root.sg28"
    ],
    [
      "INT32",
      "BOOLEAN",
      "INT32",
      "BOOLEAN"
    ],
    [
      "RLE",
      "RLE",
      "RLE",
      "RLE"
    ],
    [
      "SNAPPY",
      "SNAPPY",
      "SNAPPY",
      "SNAPPY"
    ],
    [
      null,
      null,
      null,
      null
    ],
    [
      null,
      null,
      null,
      null
    ]
  ]
}
```

**Show latest timeseries**

```shell
curl -H "Content-Type:application/json" -H "Authorization:Basic cm9vdDpyb290" -X POST --data '{"sql":"show latest timeseries"}' http://127.0.0.1:18080/rest/v1/query
```

```json
{
  "expressions": null,
  "columnNames": [
    "timeseries",
    "alias",
    "database",
    "dataType",
    "encoding",
    "compression",
    "tags",
    "attributes"
  ],
  "timestamps": null,
  "values": [
    [
      "root.sg28.s4",
      "root.sg27.s4",
      "root.sg28.s3",
      "root.sg27.s3"
    ],
    [
      null,
      null,
      null,
      null
    ],
    [
      "root.sg28",
      "root.sg27",
      "root.sg28",
      "root.sg27"
    ],
    [
      "BOOLEAN",
      "BOOLEAN",
      "INT32",
      "INT32"
    ],
    [
      "RLE",
      "RLE",
      "RLE",
      "RLE"
    ],
    [
      "SNAPPY",
      "SNAPPY",
      "SNAPPY",
      "SNAPPY"
    ],
    [
      null,
      null,
      null,
      null
    ],
    [
      null,
      null,
      null,
      null
    ]
  ]
}
```

**Count timeseries**

```shell
curl -H "Content-Type:application/json" -H "Authorization:Basic cm9vdDpyb290" -X POST --data '{"sql":"count timeseries root.**"}' http://127.0.0.1:18080/rest/v1/query
```

```json
{
  "expressions": null,
  "columnNames": [
    "count"
  ],
  "timestamps": null,
  "values": [
    [
      4
    ]
  ]
}
```

**Count nodes**

```shell
curl -H "Content-Type:application/json" -H "Authorization:Basic cm9vdDpyb290" -X POST --data '{"sql":"count nodes root.** level=2"}' http://127.0.0.1:18080/rest/v1/query
```

```json
{
  "expressions": null,
  "columnNames": [
    "count"
  ],
  "timestamps": null,
  "values": [
    [
      4
    ]
  ]
}
```

**Show devices**

```shell
curl -H "Content-Type:application/json" -H "Authorization:Basic cm9vdDpyb290" -X POST --data '{"sql":"show devices"}' http://127.0.0.1:18080/rest/v1/query
```

```json
{
  "expressions": null,
  "columnNames": [
    "devices",
    "isAligned"
  ],
  "timestamps": null,
  "values": [
    [
      "root.sg27",
      "root.sg28"
    ],
    [
      "false",
      "false"
    ]
  ]
}
```

**Show devices with database**

```shell
curl -H "Content-Type:application/json" -H "Authorization:Basic cm9vdDpyb290" -X POST --data '{"sql":"show devices with database"}' http://127.0.0.1:18080/rest/v1/query
```

```json
{
  "expressions": null,
  "columnNames": [
    "devices",
    "database",
    "isAligned"
  ],
  "timestamps": null,
  "values": [
    [
      "root.sg27",
      "root.sg28"
    ],
    [
      "root.sg27",
      "root.sg28"
    ],
    [
      "false",
      "false"
    ]
  ]
}
```

**List user**

```shell
curl -H "Content-Type:application/json" -H "Authorization:Basic cm9vdDpyb290" -X POST --data '{"sql":"list user"}' http://127.0.0.1:18080/rest/v1/query
```

```json
{
  "expressions": null,
  "columnNames": [
    "user"
  ],
  "timestamps": null,
  "values": [
    [
      "root"
    ]
  ]
}
```

**Aggregation**

```shell
curl -H "Content-Type:application/json" -H "Authorization:Basic cm9vdDpyb290" -X POST --data '{"sql":"select count(*) from root.sg27"}' http://127.0.0.1:18080/rest/v1/query
```

```json
{
  "expressions": [
    "count(root.sg27.s3)",
    "count(root.sg27.s4)"
  ],
  "columnNames": null,
  "timestamps": [
    0
  ],
  "values": [
    [
      1
    ],
    [
      2
    ]
  ]
}
```

**Group by level**

```shell
curl -H "Content-Type:application/json" -H "Authorization:Basic cm9vdDpyb290" -X POST --data '{"sql":"select count(*) from root.** group by level = 1"}' http://127.0.0.1:18080/rest/v1/query
```

```json
{
  "expressions": null,
  "columnNames": [
    "count(root.sg27.*)",
    "count(root.sg28.*)"
  ],
  "timestamps": null,
  "values": [
    [
      3
    ],
    [
      3
    ]
  ]
}
```

**Group by**

```shell
curl -H "Content-Type:application/json" -H "Authorization:Basic cm9vdDpyb290" -X POST --data '{"sql":"select count(*) from root.sg27 group by([1635232143960,1635232153960),1s)"}' http://127.0.0.1:18080/rest/v1/query
```

```json
{
  "expressions": [
    "count(root.sg27.s3)",
    "count(root.sg27.s4)"
  ],
  "columnNames": null,
  "timestamps": [
    1635232143960,
    1635232144960,
    1635232145960,
    1635232146960,
    1635232147960,
    1635232148960,
    1635232149960,
    1635232150960,
    1635232151960,
    1635232152960
  ],
  "values": [
    [
      1,
      0,
      0,
      0,
      0,
      0,
      0,
      0,
      0,
      0
    ],
    [
      1,
      0,
      0,
      0,
      0,
      0,
      0,
      0,
      0,
      0
    ]
  ]
}
```

**Last**

```shell
curl -H "Content-Type:application/json"  -H "Authorization:Basic cm9vdDpyb290" -X POST --data '{"sql":"select last s3 from root.sg27"}' http://127.0.0.1:18080/rest/v1/query
```

```json
{
  "expressions": null,
  "columnNames": [
    "timeseries",
    "value",
    "dataType"
  ],
  "timestamps": [
    1635232143960
  ],
  "values": [
    [
      "root.sg27.s3"
    ],
    [
      "11"
    ],
    [
      "INT32"
    ]
  ]
}
```

**Disable align**

```shell
curl -H "Content-Type:application/json" -H "Authorization:Basic cm9vdDpyb290" -X POST --data '{"sql":"select * from root.sg27 disable align"}' http://127.0.0.1:18080/rest/v1/query
```

```json
{
  "code": 407,
  "message": "disable align clauses are not supported."
}
```

**Align by device**

```shell
curl -H "Content-Type:application/json" -H "Authorization:Basic cm9vdDpyb290" -X POST --data '{"sql":"select count(s3) from root.sg27 align by device"}' http://127.0.0.1:18080/rest/v1/query
```

```json
{
  "code": 407,
  "message": "align by device clauses are not supported."
}
```

**Select into**

```shell
curl -H "Content-Type:application/json" -H "Authorization:Basic cm9vdDpyb290" -X POST --data '{"sql":"select s3, s4 into root.sg29.s1, root.sg29.s2 from root.sg27"}' http://127.0.0.1:18080/rest/v1/query
```

```json
{
  "code": 407,
  "message": "select into clauses are not supported."
}
```

#### nonQuery

Request method: `POST`

Request header: `application/json`

Request path: http://ip:port/rest/v1/nonQuery

Parameter Description:

|parameter name  |parameter type |parameter describe|
|:--- | :--- | :---|
|  sql | string | query content  |

Example request:
```shell
curl -H "Content-Type:application/json" -H "Authorization:Basic cm9vdDpyb290" -X POST --data '{"sql":"CREATE DATABASE root.ln"}' http://127.0.0.1:18080/rest/v1/nonQuery
```

Response parameters:

|parameter name  |parameter type |parameter describe|
|:--- | :--- | :---|
| code | integer |  status code |
| message  |  string | message |

Sample response:
```json
{
  "code": 200,
  "message": "SUCCESS_STATUS"
}
```


#### insertTablet

Request method: `POST`

Request header: `application/json`

Request path: http://ip:port/rest/v1/insertTablet

Parameter Description:

| parameter name |parameter type |is required|parameter describe|
|:---------------| :--- | :---| :---|
| timestamps     | array | yes |  Time column  |
| measurements   | array | yes  | The name of the measuring point |
| dataTypes     | array | yes  | The data type |
| values         | array | yes  | Value columns, the values in each column can be `null` |
| isAligned     | boolean | yes  | Whether to align the timeseries |
| deviceId         | string | yes  | Device name |

Example request:
```shell
curl -H "Content-Type:application/json" -H "Authorization:Basic cm9vdDpyb290" -X POST --data '{"timestamps":[1635232143960,1635232153960],"measurements":["s3","s4"],"dataTypes":["INT32","BOOLEAN"],"values":[[11,null],[false,true]],"isAligned":false,"deviceId":"root.sg27"}' http://127.0.0.1:18080/rest/v1/insertTablet
```

Sample response:

|parameter name  |parameter type |parameter describe|
|:--- | :--- | :---|
| code | integer |  status code |
| message  |  string | message |

Sample response:
```json
{
  "code": 200,
  "message": "SUCCESS_STATUS"
}
```


### Configuration

The configuration is located in 'iotdb-rest.properties'.


* Set 'enable_rest_service' to 'true' to enable the module, and 'false' to disable the module. By default, this value is' false '.

```properties
enable_rest_service=true
```

* This parameter is valid only when 'enable_REST_service =true'. Set 'rest_service_port' to a number (1025 to 65535) to customize the REST service socket port. By default, the value is 18080.

```properties
rest_service_port=18080
```

* Set 'enable_swagger' to 'true' to display rest service interface information through swagger, and 'false' to do not display the rest service interface information through the swagger. By default, this value is' false '.

```properties
enable_swagger=false
```

* The maximum number of rows in the result set that can be returned by a query. When the number of rows in the returned result set exceeds the limit, the status code `411` is returned.

````properties
rest_query_default_row_size_limit=10000
````

* Expiration time for caching customer login information (used to speed up user authentication, in seconds, 8 hours by default)

```properties
cache_expire=28800
```


* Maximum number of users stored in the cache (default: 100)

```properties
cache_max_num=100
```

* Initial cache size (default: 10)

```properties
cache_init_num=10
```

* REST Service whether to enable SSL configuration, set 'enable_https' to' true 'to enable the module, and set' false 'to disable the module. By default, this value is' false '.

```properties
enable_https=false
```

* keyStore location path (optional)

```properties
key_store_path=
```


* keyStore password (optional)

```properties
key_store_pwd=
```


* trustStore location path (optional)

```properties
trust_store_path=
```

* trustStore password (optional)

```properties
trust_store_pwd=
```


* SSL timeout period, in seconds

```properties
idle_timeout=5000
```