cube-js/cube · error · std::io::Error (ErrorKind::OutOfMemory)

Unable to convert message length to a suitable memory size

Error message

Unable to convert message length to a suitable memory size

What it means

While reading a PostgreSQL protocol message, the declared payload length (already validated against minimum and maximum bounds) could not be converted to usize::try_from(length - 4). On 64-bit targets this is effectively unreachable; on 32-bit builds it fires when a length-4 above usize::MAX leaves no room for the 4 header bytes already accounted for.

Source

Thrown at rust/cubesql/pg-srv/src/buffer.rs:135

        return Err(Error::other(format!(
            "Unexpectedly small (<4) message size {length} for tag {message_tag:X?}"
        )));
    }

    if length > max_length {
        return Err(Error::other(format!(
            "Message size {length} for tag {message_tag:X?} exceeds the maximum allowed size of {max_length} bytes"
        )));
    }

    trace!(
        "[pg] Receive package {:X?} with length {}",
        message_tag,
        length
    );

    let length = usize::try_from(length - 4).map_err(|_| {
        Error::new(
            ErrorKind::OutOfMemory,
            "Unable to convert message length to a suitable memory size",
        )
    })?;

    let buffer = if length == 0 {
        vec![0; 0]
    } else {
        let mut buffer = vec![0; length];
        reader.read_exact(&mut buffer).await?;

        buffer
    };

    let cursor = Cursor::new(buffer);

    Ok(cursor)
}

View on GitHub (pinned to 7d981676b3)

Solutions

1. Run CubeSQL on a 64-bit platform, which is the supported deployment
2. If on 32-bit, lower the maximum message size so lengths stay within usize range

When it happens

Trigger: Thrown at rust/cubesql/pg-srv/src/buffer.rs:135 when the library encounters an invalid state.

Common situations: See trigger scenarios.

AI-assisted analysis of cube-js/cube@7d981676b3 (2026-09-02). Data as JSON: /api/errors/da82961e28ac945e. Report an issue: GitHub.