influxdata/influxdb · error

prune percent must be between 0 and 1

Error message

prune percent must be between 0 and 1

What it means

Raised in the FromStr implementation of the prune-percent config type. After parsing the value as f64, it is rejected unless strictly between 0.0 and 1.0, since the prune percent is an inclusive-exclusive fraction (e.g. 0.2 for 20%).

Solutions

1. Provide the value as a fraction strictly between 0 and 1, e.g. 0.2 instead of 20 or 0.
2. Remove the prune-percent override to use the default if a custom value is not needed.
3. Check the surrounding "failed to parse prune percent as f64" context if the value is non-numeric.

Example fix

# before
--prune-percent 50
# after
--prune-percent 0.5

let p: f64 = value.parse()?;
if !(p > 0.0 && p < 1.0) {
    return Err("prune percent must be strictly between 0 and 1 (e.g. 0.5)");
}

fn valid_prune_percent(p: f64) -> bool {
    p > 0.0 && p < 1.0
}

When it happens

Trigger: Passing a value <= 0 or >= 1 for the prune percent option (e.g. `0`, `1`, `1.0`, `50` intending percent-as-integer).

Common situations: Users writing "50" meaning 50% instead of 0.5, or supplying 0/1 as boundary values that the type deliberately excludes.

Understand the failure class

Background: "value must be between 0 and 1" / "out of range" / "must not be negative" errors: fixing range-validation failures across open-source libraries — this error's family across 42 libraries.

Related errors

• Cannot parse object store config
• Could not find user's home directory
• environment variable
• invalid cache size
• invalid configuration provided

AI-assisted analysis of influxdata/influxdb@06200ef96b (2026-09-19). Data as JSON: /api/errors/0f8a899f03bf9e3f. Report an issue: GitHub.

Appendix: source

Thrown at influxdb3/src/commands/serve.rs:890

#[derive(Debug, Clone, Copy)]
pub struct ParquetCachePrunePercent(f64);

impl From<ParquetCachePrunePercent> for f64 {
    fn from(value: ParquetCachePrunePercent) -> Self {
        value.0
    }
}

impl FromStr for ParquetCachePrunePercent {
    type Err = anyhow::Error;

    fn from_str(s: &str) -> std::prelude::v1::Result<Self, Self::Err> {
        let p = s
            .parse::<f64>()
            .context("failed to parse prune percent as f64")?;
        if p <= 0.0 || p >= 1.0 {
            bail!("prune percent must be between 0 and 1");
        }
        Ok(Self(p))
    }
}

/// Apply values given through deprecated legacy aliases of renamed size
/// options to their new counterparts, and warn about pre-3.11 value formats.
///
/// An explicitly set new name wins over its legacy alias, matching the
/// precedence `env_compat` applied when the old env var name was an alias of
/// the new one.
fn resolve_legacy_size_options(config: &mut Config, user_params: &HashMap<String, String>) {
    fn apply(
        legacy: Option<LegacyMemorySizeMb>,
        legacy_flag: &str,
        new_flag: &str,
        new_value: &mut MemorySizeMb,
        user_params: &HashMap<String, String>,

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