Line protocol reference
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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
- Special characters
- 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
(Required) The measurement name. InfluxDB accepts one measurement per point. Measurement names are case-sensitive and subject to naming restrictions.
Data type: String
All tag key-value pairs for the point.
Key-value relationships are denoted with the
Multiple tag key-value pairs are comma-delimited.
Tag keys and tag values are case-sensitive.
Tag keys are subject to naming restrictions.
Tag values cannot be empty; instead, omit the tag from the tag 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.
Always double quote string field values. More on quotes below.
measurementName fieldKey="field string value" 1556813561098000000
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 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.
Data types and format
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
Signed 64-bit integers.
i on the number specifies an integer.
|Minimum integer||Maximum integer|
Integer field value examples
myMeasurement fieldKey=1i myMeasurement fieldKey=12485903i myMeasurement fieldKey=-12485903i
Unsigned 64-bit integers.
u on the number specifies an unsigned integer.
|Minimum uinteger||Maximum uinteger|
UInteger field value examples
myMeasurement fieldKey=1u myMeasurement fieldKey=12485903u
Plain text string. Length limit 64KB.
# String measurement name, field key, and field value myMeasurement fieldKey="this is a string"
|Boolean value||Accepted syntax|
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 in a specified precision.
Default precision is nanoseconds (
|Minimum timestamp||Maximum timestamp|
Unix timestamp example
myMeasurementName fieldKey="fieldValue" 1556813561098000000
Line protocol supports single and double quotes as described in the following table:
|Element||Double quotes||Single quotes|
|Measurement||Limited *||Limited *|
|Tag key||Limited *||Limited *|
|Tag value||Limited *||Limited *|
|Field key||Limited *||Limited *|
|Field value||Strings only||Never|
* 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.
Line protocol supports special characters in string elements.
In the following contexts, it requires escaping certain characters with a backslash (
|Tag key||Comma, Equals Sign, Space|
|Tag value||Comma, Equals Sign, Space|
|Field key||Comma, Equals Sign, Space|
|Field value||Double quote, 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
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:
Line protocol interprets
# at the beginning of a line as a comment character
and ignores all subsequent characters until the next newline
# This is a comment myMeasurement fieldKey="string value" 1556813561098000000
Measurement names, tag keys, and field keys cannot begin with an underscore
_ namespace is reserved for InfluxDB system use.
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.
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