OpenTSDB JSON 格式协议

TDengine企业版来源:涛思数据浏览 655 扫码分享 2023-03-11 09:24:01

OpenTSDB JSON 格式协议
- 协议介绍
  - note
示例代码
SQL 查询示例

OpenTSDB JSON 格式协议

协议介绍

OpenTSDB JSON 格式协议采用一个 JSON 字符串表示一行或多行数据。例如：

[
  {
    "metric": "sys.cpu.nice",
    "timestamp": 1346846400,
    "value": 18,
    "tags": {
      "host": "web01",
      "dc": "lga"
    }
  },
  {
    "metric": "sys.cpu.nice",
    "timestamp": 1346846400,
    "value": 9,
    "tags": {
      "host": "web02",
      "dc": "lga"
    }
  }
]

与 OpenTSDB 行协议类似， metric 将作为超级表名， timestamp 表示时间戳，value 表示度量值， tags 表示标签集。

参考OpenTSDB HTTP API 文档。

note

对于 JSON 格式协议，TDengine 并不会自动把所有标签转成 NCHAR 类型，字符串将将转为 NCHAR 类型，数值将同样转换为 DOUBLE 类型。
默认生成的子表名是根据规则生成的唯一 ID 值。用户也可以通过在 taos.cfg 里配置 smlChildTableName 参数来指定某个标签值作为子表名。该标签值应该具有全局唯一性。举例如下：假设有个标签名为tname, 配置 smlChildTableName=tname, 插入数据为 "tags": { "host": "web02","dc": "lga","tname":"cpu1"} 则创建的子表名为 cpu1。注意如果多行数据 tname 相同，但是后面的 tag_set 不同，则使用第一行自动建表时指定的 tag_set，其他的行会忽略）。

示例代码

Java
Python
Go
Node.js
C#
C

package com.taos.example;
import com.taosdata.jdbc.SchemalessWriter;
import com.taosdata.jdbc.enums.SchemalessProtocolType;
import com.taosdata.jdbc.enums.SchemalessTimestampType;
import java.sql.Connection;
import java.sql.DriverManager;
import java.sql.SQLException;
import java.sql.Statement;
public class JSONProtocolExample {
    private static Connection getConnection() throws SQLException {
        String jdbcUrl = "jdbc:TAOS://localhost:6030?user=root&password=taosdata";
        return DriverManager.getConnection(jdbcUrl);
    }
    private static void createDatabase(Connection conn) throws SQLException {
        try (Statement stmt = conn.createStatement()) {
            stmt.execute("CREATE DATABASE IF NOT EXISTS test");
            stmt.execute("USE test");
        }
    }
    private static String getJSONData() {
        return "[{\"metric\": \"meters.current\", \"timestamp\": 1648432611249, \"value\": 10.3, \"tags\": {\"location\": \"California.SanFrancisco\", \"groupid\": 2}}," +
                " {\"metric\": \"meters.voltage\", \"timestamp\": 1648432611249, \"value\": 219, \"tags\": {\"location\": \"California.LosAngeles\", \"groupid\": 1}}, " +
                "{\"metric\": \"meters.current\", \"timestamp\": 1648432611250, \"value\": 12.6, \"tags\": {\"location\": \"California.SanFrancisco\", \"groupid\": 2}}," +
                " {\"metric\": \"meters.voltage\", \"timestamp\": 1648432611250, \"value\": 221, \"tags\": {\"location\": \"California.LosAngeles\", \"groupid\": 1}}]";
    }
    public static void main(String[] args) throws SQLException {
        try (Connection conn = getConnection()) {
            createDatabase(conn);
            SchemalessWriter writer = new SchemalessWriter(conn);
            String jsonData = getJSONData();
            writer.write(jsonData, SchemalessProtocolType.JSON, SchemalessTimestampType.NOT_CONFIGURED);
        }
    }
}

import json
import taos
from taos import SmlProtocol, SmlPrecision
lines = [{"metric": "meters.current", "timestamp": 1648432611249, "value": 10.3, "tags": {"location": "California.SanFrancisco", "groupid": 2}},
         {"metric": "meters.voltage", "timestamp": 1648432611249, "value": 219,
          "tags": {"location": "California.LosAngeles", "groupid": 1}},
         {"metric": "meters.current", "timestamp": 1648432611250, "value": 12.6,
          "tags": {"location": "California.SanFrancisco", "groupid": 2}},
         {"metric": "meters.voltage", "timestamp": 1648432611250, "value": 221, "tags": {"location": "California.LosAngeles", "groupid": 1}}]
def get_connection():
    return taos.connect()
def create_database(conn):
    conn.execute("CREATE DATABASE test")
    conn.execute("USE test")
def insert_lines(conn):
    global lines
    lines = json.dumps(lines)
    # note: the first parameter must be a list with only one element.
    affected_rows = conn.schemaless_insert(
        [lines], SmlProtocol.JSON_PROTOCOL, SmlPrecision.NOT_CONFIGURED)
    print(affected_rows)  # 4
if __name__ == '__main__':
    connection = get_connection()
    try:
        create_database(connection)
        insert_lines(connection)
    finally:
        connection.close()

package main
import (
    "log"
    "github.com/taosdata/driver-go/v3/af"
)
func prepareDatabase(conn *af.Connector) {
    _, err := conn.Exec("CREATE DATABASE test")
    if err != nil {
        panic(err)
    }
    _, err = conn.Exec("USE test")
    if err != nil {
        panic(err)
    }
}
func main() {
    conn, err := af.Open("localhost", "root", "taosdata", "", 6030)
    if err != nil {
        log.Fatalln("fail to connect, err:", err)
    }
    defer conn.Close()
    prepareDatabase(conn)
    payload := `[{"metric": "meters.current", "timestamp": 1648432611249, "value": 10.3, "tags": {"location": "California.SanFrancisco", "groupid": 2}},
                {"metric": "meters.voltage", "timestamp": 1648432611249, "value": 219, "tags": {"location": "California.LosAngeles", "groupid": 1}},
                {"metric": "meters.current", "timestamp": 1648432611250, "value": 12.6, "tags": {"location": "California.SanFrancisco", "groupid": 2}},
                {"metric": "meters.voltage", "timestamp": 1648432611250, "value": 221, "tags": {"location": "California.LosAngeles", "groupid": 1}}]`
    err = conn.OpenTSDBInsertJsonPayload(payload)
    if err != nil {
        log.Fatalln("insert error:", err)
    }
}

const taos = require("@tdengine/client");
const conn = taos.connect({
  host: "localhost",
});
const cursor = conn.cursor();
function createDatabase() {
  cursor.execute("CREATE DATABASE test");
  cursor.execute("USE test");
}
function insertData() {
  const lines = [
    {
      metric: "meters.current",
      timestamp: 1648432611249,
      value: 10.3,
      tags: { location: "California.SanFrancisco", groupid: 2 },
    },
    {
      metric: "meters.voltage",
      timestamp: 1648432611249,
      value: 219,
      tags: { location: "California.LosAngeles", groupid: 1 },
    },
    {
      metric: "meters.current",
      timestamp: 1648432611250,
      value: 12.6,
      tags: { location: "California.SanFrancisco", groupid: 2 },
    },
    {
      metric: "meters.voltage",
      timestamp: 1648432611250,
      value: 221,
      tags: { location: "California.LosAngeles", groupid: 1 },
    },
  ];
  cursor.schemalessInsert(
    [JSON.stringify(lines)],
    taos.SCHEMALESS_PROTOCOL.TSDB_SML_JSON_PROTOCOL,
    taos.SCHEMALESS_PRECISION.TSDB_SML_TIMESTAMP_NOT_CONFIGURED
  );
}
try {
  createDatabase();
  insertData();
} finally {
  cursor.close(); 
  conn.close();
}

using TDengineDriver;
namespace TDengineExample
{
    internal class OptsJsonExample
    {
        static void Main()
        {
            IntPtr conn = GetConnection();
            try
            {
                PrepareDatabase(conn);
                string[] lines = { "[{\"metric\": \"meters.current\", \"timestamp\": 1648432611249, \"value\": 10.3, \"tags\": {\"location\": \"California.SanFrancisco\", \"groupid\": 2}}," +
                " {\"metric\": \"meters.voltage\", \"timestamp\": 1648432611249, \"value\": 219, \"tags\": {\"location\": \"California.LosAngeles\", \"groupid\": 1}}, " +
                "{\"metric\": \"meters.current\", \"timestamp\": 1648432611250, \"value\": 12.6, \"tags\": {\"location\": \"California.SanFrancisco\", \"groupid\": 2}}," +
                " {\"metric\": \"meters.voltage\", \"timestamp\": 1648432611250, \"value\": 221, \"tags\": {\"location\": \"California.LosAngeles\", \"groupid\": 1}}]"
            };
                IntPtr res = TDengine.SchemalessInsert(conn, lines, 1, (int)TDengineSchemalessProtocol.TSDB_SML_JSON_PROTOCOL, (int)TDengineSchemalessPrecision.TSDB_SML_TIMESTAMP_NOT_CONFIGURED);
                if (TDengine.ErrorNo(res) != 0)
                {
                    throw new Exception("SchemalessInsert failed since " + TDengine.Error(res));
                }
                else
                {
                    int affectedRows = TDengine.AffectRows(res);
                    Console.WriteLine($"SchemalessInsert success, affected {affectedRows} rows");
                }
                TDengine.FreeResult(res);
            }
            finally
            {
                TDengine.Close(conn);
            }
        }
        static IntPtr GetConnection()
        {
            string host = "localhost";
            short port = 6030;
            string username = "root";
            string password = "taosdata";
            string dbname = "";
            var conn = TDengine.Connect(host, username, password, dbname, port);
            if (conn == IntPtr.Zero)
            {
                throw new Exception("Connect to TDengine failed");
            }
            else
            {
                Console.WriteLine("Connect to TDengine success");
            }
            return conn;
        }
        static void PrepareDatabase(IntPtr conn)
        {
            IntPtr res = TDengine.Query(conn, "CREATE DATABASE test");
            if (TDengine.ErrorNo(res) != 0)
            {
                throw new Exception("failed to create database, reason: " + TDengine.Error(res));
            }
            res = TDengine.Query(conn, "USE test");
            if (TDengine.ErrorNo(res) != 0)
            {
                throw new Exception("failed to change database, reason: " + TDengine.Error(res));
            }
        }
    }
}

int main() {
  TAOS *taos = taos_connect("localhost", "root", "taosdata", "", 6030);
  if (taos == NULL) {
    printf("failed to connect to server\n");
    exit(EXIT_FAILURE);
  }
  executeSQL(taos, "DROP DATABASE IF EXISTS test");
  executeSQL(taos, "CREATE DATABASE test");
  executeSQL(taos, "USE test");
  char *line =
      "[{\"metric\": \"meters.current\", \"timestamp\": 1648432611249, \"value\": 10.3, \"tags\": {\"location\": "
      "\"California.SanFrancisco\", \"groupid\": 2}},{\"metric\": \"meters.voltage\", \"timestamp\": 1648432611249, "
      "\"value\": 219, \"tags\": {\"location\": \"California.LosAngeles\", \"groupid\": 1}},{\"metric\": \"meters.current\", "
      "\"timestamp\": 1648432611250, \"value\": 12.6, \"tags\": {\"location\": \"California.SanFrancisco\", \"groupid\": "
      "2}},{\"metric\": \"meters.voltage\", \"timestamp\": 1648432611250, \"value\": 221, \"tags\": {\"location\": "
      "\"California.LosAngeles\", \"groupid\": 1}}]";
  char     *lines[] = {line};
  TAOS_RES *res = taos_schemaless_insert(taos, lines, 1, TSDB_SML_JSON_PROTOCOL, TSDB_SML_TIMESTAMP_NOT_CONFIGURED);
  if (taos_errno(res) != 0) {
    printf("failed to insert schema-less data, reason: %s\n", taos_errstr(res));
  } else {
    int affectedRow = taos_affected_rows(res);
    printf("successfully inserted %d rows\n", affectedRow);
  }
  taos_free_result(res);
  taos_close(taos);
  taos_cleanup();
}
// output:
// successfully inserted 4 rows

以上示例代码会自动创建 2 个超级表，每个超级表有 2 条数据。

taos> USE test;
Database changed.
taos> SHOW STABLES;
              name              |
=================================
 meters.current                 |
 meters.voltage                 |
Query OK, 2 row(s) in set (0.001954s)
taos> SELECT * FROM `meters.current`;
           _ts            |           _value           |          groupid          |            location            |
===================================================================================================================
 2022-03-28 09:56:51.249 |              10.300000000 |               2.000000000 | California.SanFrancisco               |
 2022-03-28 09:56:51.250 |              12.600000000 |               2.000000000 | California.SanFrancisco               |
Query OK, 2 row(s) in set (0.004076s)

SQL 查询示例

meters.voltage 是插入数据的超级表名。

可以通过超级表的 TAG 来过滤数据，比如查询 location=California.LosAngeles groupid=1 可以通过如下 SQL：

SELECT * FROM `meters.current` WHERE location = "California.LosAngeles" AND groupid = 3;

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