influxdata/influxdb · error · Error

failed to parse line protocol

Error message

failed to parse line protocol: {0}

What it means

This error indicates the server failed to decode the request body as InfluxDB line protocol. The influxdb_line_protocol parser rejected the payload, and the underlying parser error (with line/column detail) is embedded in the message. The server returns this instead of writing any data points.

Solutions

1. Read the embedded line-protocol error for the exact line and column that failed to parse and fix the body at that position.
2. Validate the payload locally with the influxdb3_client or a line protocol linter before sending.
3. Escape special characters: commas, spaces, equals signs, and quotes in measurements/tags must be backslash-escaped.
4. Ensure the Content-Type matches (text/plain or application/octet-stream for line protocol) and the body is not accidentally compressed or truncated.
5. Send points one per line or ensure newline separators between multiple points.

Example fix

// before
let lp = "cpu,host=server01 usage=0.5"; // missing comma between tag and field
// after
let lp = "cpu,host=server01 usage=0.5"; -> "cpu,host=server01 usage=0.5"
// correct: "cpu,host=server01 usage=0.5" must be "cpu,host=server01 usage=0.5"
// i.e. "cpu,host=server01 usage=0.5" -> "cpu,host=server01 usage=0.5";

fn looks_like_line_protocol(body: &str) -> bool {
    body.lines().all(|l| {
        let l = l.trim();
        l.is_empty() || (l.contains(',') || l.contains(' ')) && l.contains('=')
    })
}

When it happens

Trigger: POSTing to /api/v3/write_lp (or v1 /write) with a body containing malformed line protocol: bad measurement/field syntax, missing field value, unescaped commas or quotes, invalid timestamp, or wrong Content-Type/encoding for the body.

Common situations: Hand-built line protocol strings with unescaped spaces or commas; CSV data pasted without conversion; timestamps in wrong precision or format; missing newline between points; gzip/compressed body sent without proper encoding handling.

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.

• Parsing and encoding errors: unexpected token, malformed input — why parsers reject input and how to find the real culprit.

Related errors

• Cannot write
• error validating database name
• influxdb3_write error
• line protocol parse failed
• write buffer error

AI-assisted analysis of influxdata/influxdb@06200ef96b (2026-09-19). Data as JSON: /api/errors/a00a9d103c982afa. Report an issue: GitHub.

Appendix: source

Thrown at influxdb3_server/src/http.rs:239

    ClientHangup(Box<dyn std::error::Error + Send + Sync>),

    /// The client sent a request body that exceeds the configured maximum.
    #[error("max request size ({0} bytes) exceeded")]
    RequestSizeExceeded(usize),

    /// Decoding a gzip-compressed stream of data failed.
    #[error("error decoding gzip stream: {0}")]
    InvalidGzip(std::io::Error),

    #[error("invalid mime type ({0})")]
    InvalidMimeType(String),

    /// DatabaseName validation error.
    #[error("error validating database name: {0}")]
    InvalidDatabaseName(#[from] DatabaseNameError),

    /// Failure to decode the provided line protocol.
    #[error("failed to parse line protocol: {0}")]
    ParseLineProtocol(influxdb_line_protocol::Error),

    /// The router is currently servicing the maximum permitted number of
    /// simultaneous requests.
    #[error("this service is overloaded, please try again later")]
    RequestLimit,

    /// The request has no authentication, but authorization is configured.
    #[error("authentication required")]
    Unauthenticated,

    /// The provided authorization is not sufficient to perform the request.
    #[error("access denied")]
    Forbidden,

    /// The HTTP request method is not supported for this resource
    #[error("unsupported method")]
    UnsupportedMethod,

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