Documentation

Work with functions

A function type is a set of parameters that perform an operation.

Function syntax

A Flux function literal contains the following:

  • Zero or more parameters enclosed in parentheses (())
    • Parameters are comma separated
    • Parameters must be named (no positional params)
    • Optionally assign a default value for each parameter with the = assignment operator. Parameters without a default value require user input and are considered required parameters.
  • => arrow operator to pass parameters into the function body.
  • Function body to define function operations and return a response.
Example functions
// Function that returns the value 1
() => 1

// Function that returns the sum of a and b
(a, b) => a + b

// Function with default values
(x=1, y=1) => x * y

// Function with a block body
(a, b, c) => { 
    d = a + b
    return d / c
}

Define functions

For information about defining custom functions, see Define custom functions.


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InfluxDB 3.9: Performance upgrade preview

InfluxDB 3 Enterprise 3.9 includes a beta of major performance upgrades with faster single-series queries, wide-and-sparse table support, and more.

InfluxDB 3 Enterprise 3.9 includes a beta of major performance and feature updates.

Key improvements:

  • Faster single-series queries
  • Consistent resource usage
  • Wide-and-sparse table support
  • Automatic distinct value caches for reduced latency with metadata queries

Preview features are subject to breaking changes.

For more information, see:

Telegraf Enterprise now in public beta

Get early access to the Telegraf Controller and provide feedback to help shape the future of Telegraf Enterprise.

See the Blog Post

The upcoming Telegraf Enterprise offering is for organizations running Telegraf at scale and is comprised of two key components:

  • Telegraf Controller: A control plane (UI + API) that centralizes Telegraf configuration management and agent health visibility.
  • Telegraf Enterprise Support: Official support for Telegraf Controller and Telegraf plugins.

Join the Telegraf Enterprise beta to get early access to the Telegraf Controller and provide feedback to help shape the future of Telegraf Enterprise.

For more information:

Telegraf Controller v0.0.6-beta now available

Telegraf Controller v0.0.6-beta is now available with new features, improvements, and bug fixes.

View the release notes
Download Telegraf Controller v0.0.6-beta

InfluxDB Docker latest tag changing to InfluxDB 3 Core

On May 27, 2026, the latest tag for InfluxDB Docker images will point to InfluxDB 3 Core. To avoid unexpected upgrades, use specific version tags in your Docker deployments.

If using Docker to install and run InfluxDB, the latest tag will point to InfluxDB 3 Core. To avoid unexpected upgrades, use specific version tags in your Docker deployments. For example, if using Docker to run InfluxDB v2, replace the latest version tag with a specific version tag in your Docker pull command–for example:

docker pull influxdb:2