Line protocol

This page documents an earlier version of InfluxDB. InfluxDB v2.7 is the latest stable version. View this page in the v2.7 documentation.

InfluxDB uses line protocol to write data points. It is a text-based format that provides the measurement, tag set, field set, and timestamp of a data point.

• Elements of line protocol
• Data types and format
• Quotes
• Special characters
• Comments
• Naming restrictions
• Duplicate points

// Syntax
<measurement>[,<tag_key>=<tag_value>[,<tag_key>=<tag_value>]] <field_key>=<field_value>[,<field_key>=<field_value>] [<timestamp>]
// Example
myMeasurement,tag1=value1,tag2=value2 fieldKey="fieldValue" 1556813561098000000

Lines separated by the newline character \n represent a single point in InfluxDB. Line protocol is whitespace sensitive.

Line protocol does not support the newline character \n in tag or field values.

Elements of line protocol

measurementName,tagKey=tagValue fieldKey="fieldValue" 1465839830100400200
--------------- --------------- --------------------- -------------------
       |               |                  |                    |
  Measurement       Tag set           Field set            Timestamp

Measurement

(Required) The measurement name. InfluxDB accepts one measurement per point. Measurement names are case-sensitive and subject to naming restrictions.

Data type: String

Tag set

Optional – All tag key-value pairs for the point. Key-value relationships are denoted with the = operand. Multiple tag key-value pairs are comma-delimited. Tag keys and tag values are case-sensitive. Tag keys are subject to naming restrictions.

Key data type: String
Value data type: String

Field set

(Required) All field key-value pairs for the point. Points must have at least one field. Field keys and string values are case-sensitive. Field keys are subject to naming restrictions.

Key data type: String
Value data type: Float | Integer | UInteger | String | Boolean

Always double quote string field values. More on quotes below.

measurementName fieldKey="field string value" 1556813561098000000

Timestamp

Optional – The unix timestamp for the data point. InfluxDB accepts one timestamp per point. If no timestamp is provided, InfluxDB uses the system time (UTC) of its host machine.

Data type: Unix timestamp

Important notes about timestamps

• To ensure a data point includes the time a metric is observed (not received by InfluxDB), include the timestamp.
• If your timestamps are not in nanoseconds, specify the precision of your timestamps when writing the data to InfluxDB.

Whitespace

Whitespace in line protocol determines how InfluxDB interprets the data point. The first unescaped space delimits the measurement and the tag set from the field set. The second unescaped space delimits the field set from the timestamp.

measurementName,tagKey=tagValue fieldKey="fieldValue" 1465839830100400200
                               |                     |
                           1st space             2nd space

Data types and format

Float

IEEE-754 64-bit floating-point numbers. Default numerical type. InfluxDB supports scientific notation in float field values.

Float field value examples

myMeasurement fieldKey=1.0
myMeasurement fieldKey=1
myMeasurement fieldKey=-1.234456e+78

Integer

Signed 64-bit integers. Trailing i on the number specifies an integer.

Integer field value examples

myMeasurement fieldKey=1i
myMeasurement fieldKey=12485903i
myMeasurement fieldKey=-12485903i

UInteger

Unsigned 64-bit integers. Trailing u on the number specifies an unsigned integer.

UInteger field value examples

myMeasurement fieldKey=1u
myMeasurement fieldKey=12485903u

String

Plain text string. Length limit 64KB.

String example

# String measurement name, field key, and field value
myMeasurement fieldKey="this is a string"

Boolean

Stores true or false values.

Boolean field value examples

myMeasurement fieldKey=true
myMeasurement fieldKey=false
myMeasurement fieldKey=t
myMeasurement fieldKey=f
myMeasurement fieldKey=TRUE
myMeasurement fieldKey=FALSE

Do not quote boolean field values. Quoted field values are interpreted as strings.

Unix timestamp

Unix timestamp in a specified precision. Default precision is nanoseconds (ns).

Unix timestamp example

myMeasurementName fieldKey="fieldValue" 1556813561098000000

Quotes

Line protocol supports single and double quotes as described in the following table:

* Line protocol accepts double and single quotes in measurement names, tag keys, tag values, and field keys, but interprets them as part of the name, key, or value.

Special Characters

Line protocol supports special characters in string elements. In the following contexts, it requires escaping certain characters with a backslash (\):

You do not need to escape other special characters.

Examples of special characters in line protocol

# Measurement name with spaces
my\ Measurement fieldKey="string value"
# Double quotes in a string field value
myMeasurement fieldKey="\"string\" within a string"
# Tag keys and values with spaces
myMeasurement,tag\ Key1=tag\ Value1,tag\ Key2=tag\ Value2 fieldKey=100
# Emojis
myMeasurement,tagKey=🍭 fieldKey="Launch 🚀" 1556813561098000000

Escaping backslashes

Line protocol supports both literal backslashes and backslashes as an escape character. With two contiguous backslashes, the first is interpreted as an escape character. For example:

Comments

Line protocol interprets # at the beginning of a line as a comment character and ignores all subsequent characters until the next newline \n.

# This is a comment
myMeasurement fieldKey="string value" 1556813561098000000

Naming restrictions

Measurement names, tag keys, and field keys cannot begin with an underscore _. The _ namespace is reserved for InfluxDB system use.

Duplicate points

A point is uniquely identified by the measurement name, tag set, and timestamp. If you submit line protocol with the same measurement, tag set, and timestamp, but with a different field set, the field set becomes the union of the old field set and the new field set, where any conflicts favor the new field set.

Related

• Write data to InfluxDB

write line protocol syntax