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## RESTful 服务
IoTDB 的 RESTful 服务可用于查询、写入和管理操作，它使用 OpenAPI 标准来定义接口并生成框架。

### 开启RESTful 服务
RESTful 服务默认情况是关闭的
 * 开发者  
   
   找到sever模块中`org.apache.iotdb.db.conf.rest` 下面的`IoTDBRestServiceConfig`类，修改`enableRestService=true`即可。

 * 使用者  
   
   找到IoTDB安装目录下面的`conf/iotdb-common.properties`文件，将 `enable_rest_service` 设置为 `true` 以启用该模块。
   
   ```properties
    enable_rest_service=true
   ```

### 鉴权
除了检活接口 `/ping`，RESTful 服务使用了基础（basic）鉴权，每次 URL 请求都需要在 header 中携带 `'Authorization': 'Basic ' + base64.encode(username + ':' + password)`。

示例中使用的用户名为：`root`，密码为：`root`，对应的 Basic 鉴权 Header 格式为

```
Authorization: Basic cm9vdDpyb2901
```

- 若用户名密码认证失败，则返回如下信息：

    HTTP 状态码：`401`

    返回结构体如下
    ```json
    {
      "code": 600,
      "message": "WRONG_LOGIN_PASSWORD_ERROR"
    }
    ```

- 若未设置 `Authorization`，则返回如下信息：

  HTTP 状态码：`401`

  返回结构体如下
    ```json
    {
      "code": 603,
      "message": "UNINITIALIZED_AUTH_ERROR"
    }
    ```

### 接口

#### ping

ping 接口可以用于线上服务检活。

请求方式：`GET`

请求路径：http://ip:port/ping

请求示例：

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

返回的 HTTP 状态码：

- `200`：当前服务工作正常，可以接收外部请求。
- `503`：当前服务出现异常，不能接收外部请求。

响应参数：

|参数名称  |参数类型  |参数描述|
| ------------ | ------------ | ------------|
| code | integer |  状态码 |
| message  |  string | 信息提示 |

响应示例：

- HTTP 状态码为 `200` 时：

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

- HTTP 状态码为 `503` 时：

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

> `/ping` 接口访问不需要鉴权。

#### query

query 接口可以用于处理数据查询和元数据查询。

请求方式：`POST`

请求头：`application/json`

请求路径：http://ip:port/rest/v2/query

参数说明:

| 参数名称      |参数类型  |是否必填|参数描述|
|-----------| ------------ | ------------ |------------ |
| sql       | string | 是  |   |
| row_limit | integer | 否 | 一次查询能返回的结果集的最大行数。<br />如果不设置该参数，将使用配置文件的  `rest_query_default_row_size_limit` 作为默认值。<br />当返回结果集的行数超出限制时，将返回状态码 `411`。 |

响应参数:

| 参数名称         |参数类型  |参数描述|
|--------------| ------------ | ------------|
| expressions  | array | 用于数据查询时结果集列名的数组，用于元数据查询时为`null`|
| column_names | array | 用于元数据查询结果集列名数组，用于数据查询时为`null` |
| timestamps   | array | 时间戳列，用于元数据查询时为`null` |
| values       |array|二维数组，第一维与结果集列名数组的长度相同，第二维数组代表结果集的一列|

请求示例如下所示：

提示:为了避免OOM问题，不推荐使用select * from root.xx.** 这种查找方式。

请求示例 表达式查询:
```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/v2/query
```

响应示例:

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

请求示例 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/v2/query
```

响应示例:

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

请求示例 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/v2/query
```

响应示例:

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

请求示例 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/v2/query
```

响应示例:

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

请求示例 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/v2/query
```

响应示例:

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

请求示例 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/v2/query
```

响应示例:

```json
{
  "expressions": null,
  "column_names": [
    "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",
      ...
    ]
  ]
}
```

请求示例 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/v2/query
```

响应示例:

```json
{
  "expressions": null,
  "column_names": [
    "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
    ]
  ]
}
```

请求示例 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/v2/query
```

响应示例:

```json
{
  "expressions": null,
  "column_names": [
    "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
    ]
  ]
}
```

请求示例 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/v2/query
```

响应示例:

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

请求示例 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/v2/query
```

响应示例:

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

请求示例 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/v2/query
```

响应示例:

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

请求示例 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/v2/query
```

响应示例:

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

请求示例 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/v2/query
```

响应示例:

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

请求示例 原始聚合查询:
```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/v2/query
```

响应示例:

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

请求示例 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/v2/query
```

响应示例:

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

请求示例 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/v2/query
```

响应示例:

```json
{
  "expressions": [
    "count(root.sg27.s3)",
    "count(root.sg27.s4)"
  ],
  "column_names": 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
    ]
  ]
}
```

请求示例 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/v2/query
```

响应示例:

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

请求示例 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/v2/query
```

响应示例:

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

请求示例 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/v2/query
```

响应示例:

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

请求示例 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/v2/query
```

响应示例:

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

#### nonQuery

请求方式：`POST`

请求头：`application/json`

请求路径：http://ip:port/rest/v2/nonQuery

参数说明:

|参数名称  |参数类型  |是否必填|参数描述|
| ------------ | ------------ | ------------ |------------ |
|  sql | string | 是  |   |

请求示例:
```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/v2/nonQuery
```

响应参数:

|参数名称  |参数类型  |参数描述|
| ------------ | ------------ | ------------|
| code | integer |  状态码 |
| message  |  string | 信息提示 |

响应示例：
```json
{
  "code": 200,
  "message": "SUCCESS_STATUS"
}
```


#### insertTablet

请求方式：`POST`

请求头：`application/json`

请求路径：http://ip:port/rest/v2/insertTablet

参数说明:

| 参数名称         |参数类型  |是否必填|参数描述|
|--------------| ------------ | ------------ |------------ |
| timestamps   | array | 是 |  时间列  |
| measurements | array | 是  | 测点名称 |
| data_types   | array | 是  | 数据类型  |
| values       | array | 是  | 值列，每一列中的值可以为 `null` |
| is_aligned   | boolean | 是  | 是否是对齐时间序列 |
| device       | string | 是  | 设备名称 |

请求示例：
```shell
curl -H "Content-Type:application/json" -H "Authorization:Basic cm9vdDpyb290" -X POST --data '{"timestamps":[1635232143960,1635232153960],"measurements":["s3","s4"],"data_types":["INT32","BOOLEAN"],"values":[[11,null],[false,true]],"is_aligned":false,"device":"root.sg27"}' http://127.0.0.1:18080/rest/v2/insertTablet
```

响应参数：

|参数名称  |参数类型  |参数描述|
| ------------ | ------------ | ------------|
| code | integer |  状态码 |
| message  |  string | 信息提示 |

响应示例：
```json
{
  "code": 200,
  "message": "SUCCESS_STATUS"
}
```


### 配置

配置位于 `iotdb-common.properties` 中。


* 将 `enable_rest_service` 设置为 `true` 以启用该模块，而将 `false` 设置为禁用该模块。默认情况下，该值为 `false`。

```properties
enable_rest_service=true
```

* 仅在 `enable_rest_service=true` 时生效。将 `rest_service_port `设置为数字（1025~65535），以自定义REST服务套接字端口。默认情况下，值为 `18080`。

```properties
rest_service_port=18080
```

* 将 'enable_swagger' 设置 'true' 启用swagger来展示rest接口信息, 而设置为 'false' 关闭该功能. 默认情况下，该值为 `false`。

```properties
enable_swagger=false
```

* 一次查询能返回的结果集最大行数。当返回结果集的行数超出参数限制时，您只会得到在行数范围内的结果集，且将得到状态码`411`。

```properties
rest_query_default_row_size_limit=10000
```

* 缓存客户登录信息的过期时间（用于加速用户鉴权的速度，单位为秒，默认是8个小时）

```properties
cache_expire=28800
```

* 缓存中存储的最大用户数量（默认是100）

```properties
cache_max_num=100
```

* 缓存初始容量（默认是10）

```properties
cache_init_num=10
```

* REST Service 是否开启 SSL 配置，将 `enable_https` 设置为 `true` 以启用该模块，而将 `false` 设置为禁用该模块。默认情况下，该值为 `false`。

```properties
enable_https=false
```

* keyStore 所在路径（非必填）

```properties
key_store_path=
```


* keyStore 密码（非必填）

```properties
key_store_pwd=
```


* trustStore 所在路径（非必填）

```properties
trust_store_path=
```

* trustStore 密码（非必填）

```properties
trust_store_pwd=
```


* SSL 超时时间，单位为秒

```properties
idle_timeout=5000
```