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Get started writing data

This tutorial walks you through the fundamental of creating line protocol data and writing it to InfluxDB.

InfluxDB provides many different options for ingesting or writing data, including the following:

  • InfluxDB HTTP API (v1 and v2)
  • Telegraf
  • influxctl CLI
  • influx3 data CLI
  • InfluxDB client libraries

If using tools like Telegraf or InfluxDB client libraries, they can build the line protocol for you, but it’s good to understand how line protocol works.

Line protocol

All data written to InfluxDB is written using line protocol, a text-based format that lets you provide the necessary information to write a data point to InfluxDB. This tutorial covers the basics of line protocol, but for detailed information, see the Line protocol reference.

Line protocol elements

Each line of line protocol contains the following elements:

* Required
  • * measurement: A string that identifies the table to store the data in.
  • tag set: Comma-delimited list of key value pairs, each representing a tag. Tag keys and values are unquoted strings. Spaces, commas, and equal characters must be escaped.
  • * field set: Comma-delimited list of key value pairs, each representing a field. Field keys are unquoted strings. Spaces and commas must be escaped. Field values can be strings (quoted), floats, integers, unsigned integers, or booleans.
  • timestamp: Unix timestamp associated with the data. InfluxDB supports up to nanosecond precision. If the precision of the timestamp is not in nanoseconds, you must specify the precision when writing the data to InfluxDB.

Line protocol element parsing

  • measurement: Everything before the first unescaped comma before the first whitespace.
  • tag set: Key-value pairs between the first unescaped comma and the first unescaped whitespace.
  • field set: Key-value pairs between the first and second unescaped whitespaces.
  • timestamp: Integer value after the second unescaped whitespace.
  • Lines are separated by the newline character (\n). Line protocol is whitespace sensitive.

myMeasurement,tag1=val1,tag2=val2 field1="v1",field2=1i 0000000000000000000


For schema design recommendations, see InfluxDB schema design.

Construct line protocol

With a basic understanding of line protocol, you can now construct line protocol and write data to InfluxDB. Consider a use case where you collect data from sensors in your home. Each sensor collects temperature, humidity, and carbon monoxide readings. To collect this data, use the following schema:

  • measurement: home
    • tags
      • room: Living Room or Kitchen
    • fields
      • temp: temperature in °C (float)
      • hum: percent humidity (float)
      • co: carbon monoxide in parts per million (integer)
    • timestamp: Unix timestamp in second precision

The following line protocol sample represents data collected hourly beginning at 2025-06-14T08:00:00Z (UTC) until 2025-06-14T20:00:00Z (UTC).

Home sensor data line protocol
home,room=Living\ Room temp=21.1,hum=35.9,co=0i 1749888000
home,room=Kitchen temp=21.0,hum=35.9,co=0i 1749888000
home,room=Living\ Room temp=21.4,hum=35.9,co=0i 1749891600
home,room=Kitchen temp=23.0,hum=36.2,co=0i 1749891600
home,room=Living\ Room temp=21.8,hum=36.0,co=0i 1749895200
home,room=Kitchen temp=22.7,hum=36.1,co=0i 1749895200
home,room=Living\ Room temp=22.2,hum=36.0,co=0i 1749898800
home,room=Kitchen temp=22.4,hum=36.0,co=0i 1749898800
home,room=Living\ Room temp=22.2,hum=35.9,co=0i 1749902400
home,room=Kitchen temp=22.5,hum=36.0,co=0i 1749902400
home,room=Living\ Room temp=22.4,hum=36.0,co=0i 1749906000
home,room=Kitchen temp=22.8,hum=36.5,co=1i 1749906000
home,room=Living\ Room temp=22.3,hum=36.1,co=0i 1749909600
home,room=Kitchen temp=22.8,hum=36.3,co=1i 1749909600
home,room=Living\ Room temp=22.3,hum=36.1,co=1i 1749913200
home,room=Kitchen temp=22.7,hum=36.2,co=3i 1749913200
home,room=Living\ Room temp=22.4,hum=36.0,co=4i 1749916800
home,room=Kitchen temp=22.4,hum=36.0,co=7i 1749916800
home,room=Living\ Room temp=22.6,hum=35.9,co=5i 1749920400
home,room=Kitchen temp=22.7,hum=36.0,co=9i 1749920400
home,room=Living\ Room temp=22.8,hum=36.2,co=9i 1749924000
home,room=Kitchen temp=23.3,hum=36.9,co=18i 1749924000
home,room=Living\ Room temp=22.5,hum=36.3,co=14i 1749927600
home,room=Kitchen temp=23.1,hum=36.6,co=22i 1749927600
home,room=Living\ Room temp=22.2,hum=36.4,co=17i 1749931200
home,room=Kitchen temp=22.7,hum=36.5,co=26i 1749931200
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Write line protocol to InfluxDB

The following examples show how to write the preceding sample data, already in line protocol format, to an InfluxDB Clustered database.

To learn more about available tools and options, see Write data.

Some examples in this getting started tutorial assume your InfluxDB credentials (URL, organization, and token) are provided by environment variables.

Use Telegraf to consume line protocol, and then write it to InfluxDB Clustered.

  1. If you haven’t already, follow the instructions to download and install Telegraf.

  2. Copy and save the home sensor data sample to a file on your local system–for example, home.lp.

    cat <<- EOF > home.lp
    home,room=Living\ Room temp=21.1,hum=35.9,co=0i 1749888000
    home,room=Kitchen temp=21.0,hum=35.9,co=0i 1749888000
    home,room=Living\ Room temp=21.4,hum=35.9,co=0i 1749891600
    home,room=Kitchen temp=23.0,hum=36.2,co=0i 1749891600
    home,room=Living\ Room temp=21.8,hum=36.0,co=0i 1749895200
    home,room=Kitchen temp=22.7,hum=36.1,co=0i 1749895200
    home,room=Living\ Room temp=22.2,hum=36.0,co=0i 1749898800
    home,room=Kitchen temp=22.4,hum=36.0,co=0i 1749898800
    home,room=Living\ Room temp=22.2,hum=35.9,co=0i 1749902400
    home,room=Kitchen temp=22.5,hum=36.0,co=0i 1749902400
    home,room=Living\ Room temp=22.4,hum=36.0,co=0i 1749906000
    home,room=Kitchen temp=22.8,hum=36.5,co=1i 1749906000
    home,room=Living\ Room temp=22.3,hum=36.1,co=0i 1749909600
    home,room=Kitchen temp=22.8,hum=36.3,co=1i 1749909600
    home,room=Living\ Room temp=22.3,hum=36.1,co=1i 1749913200
    home,room=Kitchen temp=22.7,hum=36.2,co=3i 1749913200
    home,room=Living\ Room temp=22.4,hum=36.0,co=4i 1749916800
    home,room=Kitchen temp=22.4,hum=36.0,co=7i 1749916800
    home,room=Living\ Room temp=22.6,hum=35.9,co=5i 1749920400
    home,room=Kitchen temp=22.7,hum=36.0,co=9i 1749920400
    home,room=Living\ Room temp=22.8,hum=36.2,co=9i 1749924000
    home,room=Kitchen temp=23.3,hum=36.9,co=18i 1749924000
    home,room=Living\ Room temp=22.5,hum=36.3,co=14i 1749927600
    home,room=Kitchen temp=23.1,hum=36.6,co=22i 1749927600
    home,room=Living\ Room temp=22.2,hum=36.4,co=17i 1749931200
    home,room=Kitchen temp=22.7,hum=36.5,co=26i 1749931200
    EOF
    
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  3. Run the following command to generate a Telegraf configuration file (telegraf.conf) that enables the inputs.file and outputs.influxdb_v2 plugins:

    mkdir -p iot-project \
    && telegraf --sample-config \
      --input-filter file \
      --output-filter influxdb_v2 \
      > iot-project/telegraf.conf
    
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  4. In your editor, open iot-project/telegraf.conf and configure the following:

    • file input plugin: In the [[inputs.file]].files list, replace "/tmp/metrics.out" with your sample data filename. If Telegraf can’t find a file when started, it stops processing and exits.

      [[inputs.file]]
        ## Files to parse each interval.  Accept standard unix glob matching rules,
        ## as well as ** to match recursive files and directories.
        files = ["home.lp"]
        # Set the timestamp precision to the precision in your data.
        influx_timestamp_precision = '1s'
        ## Optionally, use the newer, more efficient line protocol parser
        influx_parser_type = 'upstream' 
      
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View the written data

Congratulations! You’ve written data to InfluxDB. Next, learn how to query your data.


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