influxdata/influxdb · error · Error

More than one '_'

Error message

More than one '_'

What it means

split_namespace enforces that the namespace string contains exactly one '_' separator. If the iterator still yields another segment after extracting org_id and bucket_id, the string had multiple underscores (e.g. "a_b_c") and this error is thrown, because org or bucket ids cannot contain underscores under this encoding.

Solutions

  1. Use namespace strings with exactly one underscore: '<org_id>_<bucket_id>' where neither id contains '_'
  2. Rename org/bucket identifiers to exclude underscores, or use a different delimiter/encoding if the scheme allows
  3. Pre-validate with a check that s.match_indices('_').count() == 1 before calling

Example fix

// before
let (org, bucket) = split_namespace("my_org_mybucket")?; // two '_'
// after
let (org, bucket) = split_namespace("myorg_mybucket")?; // exactly one '_'
Defensive patterns

Strategy: validation

Validate before calling

fn exactly_one_underscore(ns: &str) -> bool {
    ns.match_indices('_').count() == 1
}

Type guard

fn safe_split(ns: &str) -> Option<(&str, &str)> {
    let mut it = ns.split('_');
    let org = it.next()?;
    let bucket = it.next()?;
    it.next().is_none().then(|| (org, bucket))
}

Try / catch

match split_namespace(ns) {
    Ok((org, bucket)) => /* ... */,
    Err(e) if e.to_string().contains("More than one") => eprintln!("namespace '{}' has embedded underscores", ns),
    Err(e) => eprintln!("{}", e),
}

Prevention

When it happens

Trigger: Calling split_namespace with strings containing two or more underscores such as "my_org_bucket" or "a_b_c_d"; exercised by tests split_too_many and split_way_too_many.

Common situations: Org or bucket names that themselves contain underscores being joined with '_'; users assuming multi-underscore names are supported; legacy identifiers not migrated to the underscore-free scheme.

Understand the failure class

Background: "Invalid ... format", "must be in format X", "does not look like a ..." — invalid argument format errors across CLI tools and libraries — this error's family across 17 libraries.

Related errors

AI-assisted analysis of influxdata/influxdb@06200ef96b (2026-09-19). Data as JSON: /api/errors/1aa455b03b9194c9. Report an issue: GitHub.

Appendix: source

Thrown at core/client_util/src/namespace_translation.rs:40

/// Splits up the namespace name into org_id and bucket_id
pub fn split_namespace(namespace: &str) -> Result<(&str, &str), Error> {
    let mut iter = namespace.split('_');
    let org_id = iter.next().ok_or_else(|| Error::new(namespace, "empty"))?;

    if org_id.is_empty() {
        return Err(Error::new(namespace, "No org_id found"));
    }

    let bucket_id = iter
        .next()
        .ok_or_else(|| Error::new(namespace, "Could not find '_'"))?;

    if bucket_id.is_empty() {
        return Err(Error::new(namespace, "No bucket_id found"));
    }

    if iter.next().is_some() {
        return Err(Error::new(namespace, "More than one '_'"));
    }

    Ok((org_id, bucket_id))
}

#[cfg(test)]
mod test {
    use super::*;

    #[test]
    fn split_good() {
        assert_eq!(split_namespace("foo_bar").unwrap(), ("foo", "bar"));
    }

    #[test]
    #[should_panic(expected = "No org_id found")]
    fn split_bad_empty() {
        split_namespace("").unwrap();

View on GitHub (pinned to 06200ef96b)