OpenTSDB Line Protocol

Introduction

A single line of text is used in OpenTSDB line protocol to represent one row of data. OpenTSDB employs a single column data model, so each line can only contain a single data column. There can be multiple tags. Each line contains 4 parts as below:

<metric> <timestamp> <value> <tagk_1>=<tagv_1>[ <tagk_n>=<tagv_n>]

metric will be used as the STable name.
timestamp is the timestamp of current row of data. The time precision will be determined automatically based on the length of the timestamp. Second and millisecond time precision are supported.
value is a metric which must be a numeric value, The corresponding column name is "value".
The last part is the tag set separated by spaces, all tags will be converted to NCHAR type automatically.

For example:

meters.current 1648432611250 11.3 location=California.LosAngeles groupid=3

The rule of table name
- The child table name is created automatically in a rule to guarantee its uniqueness.
- You can configure smlAutoChildTableNameDelimiter in taos.cfg to specify a delimiter between tag values as the table names. For example, you set smlAutoChildTableNameDelimiter=- in taos.cfg, when you insert st,t0=cpu1,t1=4 c1=3 1626006833639000000, the child table will be cpu1-4
- You can configure smlChildTableName in taos.cfg to specify a tag value as the table names if the tag value is unique globally. For example, if a tag is called tname and you set smlChildTableName=tname in taos.cfg, when you insert st,tname=cpu1,t1=4 c1=3 1626006833639000000, the child table cpu1 will be created automatically. Note that if multiple rows have the same tname but different tag_set values, the tag_set of the first row is used to create the table and the others are ignored
Please refer to OpenTSDB Telnet API for more details.

Examples

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 TelnetLineProtocolExample {
    // format: <metric> <timestamp> <value> <tagk_1>=<tagv_1>[ <tagk_n>=<tagv_n>]
    private static String[] lines = { "meters.current 1648432611249 10.3 location=California.SanFrancisco groupid=2",
            "meters.current 1648432611250 12.6 location=California.SanFrancisco groupid=2",
            "meters.current 1648432611249 10.8 location=California.LosAngeles groupid=3",
            "meters.current 1648432611250 11.3 location=California.LosAngeles groupid=3",
            "meters.voltage 1648432611249 219 location=California.SanFrancisco groupid=2",
            "meters.voltage 1648432611250 218 location=California.SanFrancisco groupid=2",
            "meters.voltage 1648432611249 221 location=California.LosAngeles groupid=3",
            "meters.voltage 1648432611250 217 location=California.LosAngeles groupid=3",
    };

    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()) {
            // the default precision is ms (microsecond), but we use us(microsecond) here.
            stmt.execute("CREATE DATABASE IF NOT EXISTS test precision 'us'");
            stmt.execute("USE test");
        }
    }

    public static void main(String[] args) throws SQLException {
        try (Connection conn = getConnection()) {
            createDatabase(conn);
            SchemalessWriter writer = new SchemalessWriter(conn);
            writer.write(lines, SchemalessProtocolType.TELNET, SchemalessTimestampType.NOT_CONFIGURED);
        }
    }

}

view source code

import taos
from taos import SmlProtocol, SmlPrecision

# format: <metric> <timestamp> <value> <tagk_1>=<tagv_1>[ <tagk_n>=<tagv_n>]
lines = ["meters.current 1648432611249 10.3 location=California.SanFrancisco groupid=2",
         "meters.current 1648432611250 12.6 location=California.SanFrancisco groupid=2",
         "meters.current 1648432611249 10.8 location=California.LosAngeles groupid=3",
         "meters.current 1648432611250 11.3 location=California.LosAngeles groupid=3",
         "meters.voltage 1648432611249 219 location=California.SanFrancisco groupid=2",
         "meters.voltage 1648432611250 218 location=California.SanFrancisco groupid=2",
         "meters.voltage 1648432611249 221 location=California.LosAngeles groupid=3",
         "meters.voltage 1648432611250 217 location=California.LosAngeles groupid=3",
         ]


# create connection use firstEp in taos.cfg.
def get_connection():
    return taos.connect()


def create_database(conn):
    conn.execute("CREATE DATABASE test keep 36500")
    conn.execute("USE test")


def insert_lines(conn):
    affected_rows = conn.schemaless_insert(
        lines, SmlProtocol.TELNET_PROTOCOL, SmlPrecision.NOT_CONFIGURED)
    print(affected_rows)  # 8


if __name__ == '__main__':
    connection = get_connection()
    try:
        create_database(connection)
        insert_lines(connection)
    finally:
        connection.close()

view source code

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)
	var lines = []string{
		"meters.current 1648432611249 10.3 location=California.SanFrancisco groupid=2",
		"meters.current 1648432611250 12.6 location=California.SanFrancisco groupid=2",
		"meters.current 1648432611249 10.8 location=California.LosAngeles groupid=3",
		"meters.current 1648432611250 11.3 location=California.LosAngeles groupid=3",
		"meters.voltage 1648432611249 219 location=California.SanFrancisco groupid=2",
		"meters.voltage 1648432611250 218 location=California.SanFrancisco groupid=2",
		"meters.voltage 1648432611249 221 location=California.LosAngeles groupid=3",
		"meters.voltage 1648432611250 217 location=California.LosAngeles groupid=3",
	}

	err = conn.OpenTSDBInsertTelnetLines(lines)
	if err != nil {
		log.Fatalln("insert error:", err)
	}
}

view source code

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 = [
    "meters.current 1648432611249 10.3 location=California.SanFrancisco groupid=2",
    "meters.current 1648432611250 12.6 location=California.SanFrancisco groupid=2",
    "meters.current 1648432611249 10.8 location=California.LosAngeles groupid=3",
    "meters.current 1648432611250 11.3 location=California.LosAngeles groupid=3",
    "meters.voltage 1648432611249 219 location=California.SanFrancisco groupid=2",
    "meters.voltage 1648432611250 218 location=California.SanFrancisco groupid=2",
    "meters.voltage 1648432611249 221 location=California.LosAngeles groupid=3",
    "meters.voltage 1648432611250 217 location=California.LosAngeles groupid=3",
  ];
  cursor.schemalessInsert(
    lines,
    taos.SCHEMALESS_PROTOCOL.TSDB_SML_TELNET_PROTOCOL,
    taos.SCHEMALESS_PRECISION.TSDB_SML_TIMESTAMP_NOT_CONFIGURED
  );
}

try {
  createDatabase();
  insertData();
} finally {
  cursor.close();
  conn.close();
}

view source code

using TDengine.Driver;
using TDengine.Driver.Client;

namespace TDengineExample
{
    internal class OptsTelnetExample
    {
        public static void Main(string[] args)
        {
            var builder =
                new ConnectionStringBuilder("host=localhost;port=6030;username=root;password=taosdata");
            using (var client = DbDriver.Open(builder))
            {
                client.Exec("CREATE DATABASE test WAL_RETENTION_PERIOD 3600");
                client.Exec("USE test");
                string[] lines = {
                    "meters.current 1648432611249 10.3 location=California.SanFrancisco groupid=2",
                    "meters.current 1648432611250 12.6 location=California.SanFrancisco groupid=2",
                    "meters.current 1648432611249 10.8 location=California.LosAngeles groupid=3",
                    "meters.current 1648432611250 11.3 location=California.LosAngeles groupid=3",
                    "meters.voltage 1648432611249 219 location=California.SanFrancisco groupid=2",
                    "meters.voltage 1648432611250 218 location=California.SanFrancisco groupid=2",
                    "meters.voltage 1648432611249 221 location=California.LosAngeles groupid=3",
                    "meters.voltage 1648432611250 217 location=California.LosAngeles groupid=3",
                };
                client.SchemalessInsert(lines,
                    TDengineSchemalessProtocol.TSDB_SML_TELNET_PROTOCOL,
                    TDengineSchemalessPrecision.TSDB_SML_TIMESTAMP_MILLI_SECONDS, 0, ReqId.GetReqId());
            }
        }
    }
}

view source code

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 *lines[] = {
      "meters.current 1648432611249 10.3 location=California.SanFrancisco groupid=2",
      "meters.current 1648432611250 12.6 location=California.SanFrancisco groupid=2",
      "meters.current 1648432611249 10.8 location=California.LosAngeles groupid=3",
      "meters.current 1648432611250 11.3 location=California.LosAngeles groupid=3",
      "meters.voltage 1648432611249 219 location=California.SanFrancisco groupid=2",
      "meters.voltage 1648432611250 218 location=California.SanFrancisco groupid=2",
      "meters.voltage 1648432611249 221 location=California.LosAngeles groupid=3",
      "meters.voltage 1648432611250 217 location=California.LosAngeles groupid=3",
  };
  TAOS_RES *res = taos_schemaless_insert(taos, lines, 8, TSDB_SML_TELNET_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 8 rows

view source code

2 STables will be created automatically and each STable has 4 rows of data in the above sample code.

taos> use test;
Database changed.

taos> show stables;
              name              |
=================================
 meters_current                 |
 meters_voltage                 |
Query OK, 2 row(s) in set (0.002544s)

taos> select tbname, * from `meters_current`;
             tbname             |           _ts            |           _value           | groupid |            location            |
==================================================================================================================================
 t_0e7bcfa21a02331c06764f275... | 2022-03-28 09:56:51.249 |              10.800000000 | 3       | California.LosAngeles                |
 t_0e7bcfa21a02331c06764f275... | 2022-03-28 09:56:51.250 |              11.300000000 | 3       | California.LosAngeles                |
 t_7e7b26dd860280242c6492a16... | 2022-03-28 09:56:51.249 |              10.300000000 | 2       | California.SanFrancisco               |
 t_7e7b26dd860280242c6492a16... | 2022-03-28 09:56:51.250 |              12.600000000 | 2       | California.SanFrancisco               |
Query OK, 4 row(s) in set (0.005399s)

Query Examples

If you want query the data of location=California.LosAngeles groupid=3, here is the query SQL:

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

Introduction​

Examples​

Query Examples​

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Introduction

Examples

Query Examples