InfluxDB Contents

Write Syntax

This is archived documentation for InfluxData product versions that are no longer maintained. For newer documentation, see the latest InfluxData documentation.

Syntax is always a challenge to remember, so here’s a reference

Line Protocol

The syntax for the line protocol is

measurement[,tag_key1=tag_value1...] field_key=field_value[,field_key2=field_value2] [timestamp]

For example:

measurement,tkey1=tval1,tkey2=tval2 fkey=fval,fkey2=fval2 1234567890000000000

Whitespace

A space must exist between the measurement and the field(s), or between the tag(s) and the field(s) if tags are provided. The measurement and tags must be separated by a single comma , with no whitespace.

There must also be whitespace between the field(s) and the timestamp, if one is provided.

Valid (value and otherval are fields, foo and bat are tags)

measurement value=12
measurement value=12 1439587925
measurement,foo=bar value=12
measurement,foo=bar value=12 1439587925
measurement,foo=bar,bat=baz value=12,otherval=21 1439587925

Invalid

measurement,value=12
measurement value=12,1439587925
measurement foo=bar value=12
measurement,foo=bar,value=12 1439587925
measurement,foo=bar
measurement,foo=bar 1439587925

Timestamps

Timestamps are not required. When no timestamp is provided the server will insert the point with the local server timestamp. If a timestamp is provided it must be separated from the field(s) by a space. Timestamps must be in Unix time and are assumed to be in nanoseconds. A different precision can be specified, see the HTTP syntax for details. We recommend using the least precise precision possible as this can result in significant improvements in compression.

Key-value Separator

Tag keys and values, and field keys and values must be separated by the equals sign = without spaces.

Escaping Characters

If a tag key, tag value, or field key contains a space , comma ,, or an equals sign = it must be escaped using the backslash character \. Backslash characters do not need to be escaped. Commas , and spaces will also need to be escaped for measurements, though equals signs = do not.

Comments

# at the beginning of the line is a valid comment character for the line protocol. All subsequent characters are ignored.

Data Types

Measurements, tag keys, tag values, and field keys are always stored as strings in the database.

string values have a length limit of 64 KB. All Unicode characters should be valid, although commas and spaces require escaping. Backslash characters do not require escaping, but may not be used directly preceding a comma or space. (Note that string field values have different quoting and escaping rules than the measurement, tag, and field name string syntax.) The field location="us-west" stores a string value.

Field values may be stored as float64, int64, boolean, or string. All subsequent field values must match the type of the first point written to given measurement.

float64 values are the default numerical type. 1 is a float, 1i is an integer.

int64 values must have a trailing i. The field bikes_present=15i stores an integer and the field bikes_present=15 stores a float.

boolean values are t, T, true, True, or TRUE for TRUE, and f, F, false, False, or FALSE for FALSE

string values for field values must be double-quoted. Double-quotes contained within the string must be escaped. All other characters are supported without escaping.

Examples

Simplest Valid Point (measurement + field)

disk_free value=442221834240i

With Timestamp

disk_free value=442221834240i 1435362189575692182

With Tags

disk_free,hostname=server01,disk_type=SSD value=442221834240i

With Tags, With Timestamp

disk_free,hostname=server01,disk_type=SSD value=442221834240i 1435362189575692182

Multiple Fields

disk_free free_space=442221834240i,disk_type="SSD" 1435362189575692182

Escaping Commas and Spaces

total\ disk\ free,volumes=/net\,/home\,/ value=442221834240i 1435362189575692182

In the above example, the measurement is written as total disk free and the tag key volumes has a tag value of /net,/home,/

Escaping Equals Signs

disk_free,a\=b=y\=z value=442221834240i

In the above example, the tag key a=b has a tag value of y=z

With Backslash in Tag Value

disk_free,path=C:\Windows value=442221834240i

Backslashes do not need to be escaped when used in strings. Unless followed by a comma, space, or equals sign backslashes are treated as a normal character.

Escaping Field Key

disk_free value=442221834240i,working\ directories="C:\My Documents\Stuff for examples,C:\My Documents"

In the above example, the second field key is working directories and the corresponding field value is C:\My Documents\Stuff for examples,C:\My Documents.

Showing all escaping and quoting behavior

"measurement\ with\ quotes",tag\ key\ with\ spaces=tag\,value\,with"commas" field_key\\\\="string field value, only \" need be quoted"

In the above example, the measurement is "measurement with quotes", the tag key is tag key with spaces, the tag value is tag,value,with"commas", the field key is field_key\\\\ and the field value is string field value, only " need be quoted.

Caveats

If you write points in a batch all points without explicit timestamps will receive the same timestamp when inserted. Since a point is defined only by its measurement, tag set, and timestamp, that can lead to duplicate points. When InfluxDB encounters a duplicate point, the field set becomes the union of the old field set and the new field set, where any ties go to the new field set. It is a best practice to provide explicit timestamps with all points.

Measurements, tag keys, tag values, and field keys are never quoted. Spaces and commas must be escaped. Field values that are stored as strings must always be double-quoted. Only double-quotes should be escaped.

Querying measurements or tags that contain double-quotes " can be difficult, since double-quotes are also the syntax for an identifier. It’s possible to work around the limitations with regular expressions but it’s not easy.

Avoid using Keywords as identifiers (database names, retention policy names, measurement names, tag keys, or field keys) whenever possible. Keywords in InfluxDB are referenced on the InfluxQL Syntax page. There is no need to quote or escape keywords in the write syntax.

All values in InfluxDB are case-sensitive: MyDB != mydb != MYDB. The exception is Keywords, which are case-insensitive.

CLI

To write points using the command line interface, use the insert command.

Write a Point with the CLI

> insert disk_free,hostname=server01 value=442221834240i 1435362189575692182

The CLI will return nothing on success and should give an informative parser error if the point cannot be written. There is currently no way to write a batch of points using the CLI, each point must be inserted individually.

HTTP

To write points using HTTP, POST to the /write endpoint at port 8086. You must specify the target database in the query string using db=<target_database>.

You may optionally provide a target retention policy, specify the precision of any supplied timestamps, and pass any required authentication in the query string.

Successful writes will return a 204 HTTP Status Code. Writes will return a 400 for invalid syntax.

Query String Parameters for Writes

The following query string parameters can be passed as part of the GET string when using the HTTP API:

  • db=<database> REQUIRED - sets the target database for the write
  • rp=<retention_policy> - sets the target retention policy for the write. If not present the default retention policy is used
  • u=<username>, p=<password> - if authentication is enabled, you must authenticate as a user with write permissions to the target database
  • precision=[n,u,ms,s,m,h] - sets the precision of the supplied Unix time values. If not present timestamps are assumed to be in nanoseconds
  • consistency=[one,quorum,all,any] - set the number of nodes that must confirm the write. If the requirement is not met the return value will be partial write if some points in the batch fail, or write failure if all points in the batch fail.
    • one - the data must be written to disk by at least 1 valid node
    • quorum - the data must be written to disk by (N/2 + 1) valid nodes (N is the replication factor for the target retention policy)
    • all - the data must be written to disk by all valid nodes
    • any - a write is confirmed if hinted-handoff is successful, even if all target nodes report a write failure In this context, “valid node” means a node that hosts a copy of the shard containing the series being written to. In a clustered system, the replication factor should equal the number of valid nodes.

Write a Point with curl

curl -X POST 'http://localhost:8086/write?db=mydb' --data-binary 'disk_free,hostname=server01 value=442221834240i 1435362189575692182'

Write a Point to a non-default Retention Policy

Use the rp=<retention_policy query string parameter to supply a target retention policy. If not specified, the default retention policy for the target database will be used.

curl -X POST 'http://localhost:8086/write?db=mydb&rp=six_month_rollup' --data-binary 'disk_free,hostname=server01 value=442221834240i 1435362189575692182'

Write a Point Using Authentication

Use the u=<user> and p=<password> to pass the authentication details, if required.

curl -X POST 'http://localhost:8086/write?db=mydb&u=root&p=123456' --data-binary 'disk_free,hostname=server01 value=442221834240i 1435362189575692182'

Specify Non-nanosecond Timestamps

Use the precision=[n,u,ms,s,m,h] query string parameter to supply a precision for the timestamps.

All timestamps are assumed to be Unix nanoseconds unless otherwise specified. If you provide timestamps in any unit other than nanoseconds, you must supply the appropriate precision in the URL query string. Use n, u, ms, s, m, and h for nanoseconds, microseconds, milliseconds, seconds, minutes, and hours, respectively.

curl -X POST 'http://localhost:8086/write?db=mydb&precision=ms' --data-binary 'disk_free value=442221834240i 1435362189575'

Write a Batch of Points with curl

You can also pass a file using the @ flag. The file can contain a batch of points, one per line. Points must be separated by newline characters \n. Batches should be 5000 points or fewer for best performance.

curl -X POST 'http://localhost:8086/write?db=<database>' --data-binary @<filename>

Caveats

Use curl’s --data-binary encoding method for all writes in the line protocol format. Using any encoding method other than --data-binary is likely to lead to issues with writing points. -d, --data-urlencode, and --data-ascii may all strip out newlines or introduce new unintended formatting.

When passing a file to curl, the points must be separated by newline characters only (\n). Files containing carriage returns will cause parser errors.