vectordotdev/vector · info

Default maximum data file size should never be greater than

Error message

Default maximum data file size should never be greater than 2^64 bytes.

What it means

When building a DiskBufferConfig without an explicit `max_data_file_size`, Vector converts the DEFAULT_MAX_DATA_FILE_SIZE constant (128 MiB, defined in common.rs) from `usize` to `u64`. The constant is fixed and fits trivially, so the expect is an assertion about build-time values only; it cannot fire for any user configuration.

Source

Thrown at lib/vector-buffers/src/variants/disk_v2/common.rs:324

        FS2: Filesystem,
    {
        DiskBufferConfigBuilder {
            data_dir: self.data_dir,
            max_buffer_size: self.max_buffer_size,
            max_data_file_size: self.max_data_file_size,
            max_record_size: self.max_record_size,
            write_buffer_size: self.write_buffer_size,
            flush_interval: self.flush_interval,
            filesystem,
        }
    }

    /// Consumes this builder and constructs a `DiskBufferConfig`.
    pub fn build(self) -> Result<DiskBufferConfig<FS>, BuildError> {
        let max_buffer_size = self.max_buffer_size.unwrap_or(u64::MAX);
        let max_data_file_size = self.max_data_file_size.unwrap_or_else(|| {
            u64::try_from(DEFAULT_MAX_DATA_FILE_SIZE)
                .expect("Default maximum data file size should never be greater than 2^64 bytes.")
        });
        let max_record_size = self.max_record_size.unwrap_or(DEFAULT_MAX_RECORD_SIZE);
        let write_buffer_size = self.write_buffer_size.unwrap_or(DEFAULT_WRITE_BUFFER_SIZE);
        let flush_interval = self.flush_interval.unwrap_or(DEFAULT_FLUSH_INTERVAL);
        let filesystem = self.filesystem;

        // Validate the input parameters.
        if max_data_file_size == 0 {
            return Err(BuildError::InvalidParameter {
                param_name: "max_data_file_size",
                reason: "cannot be zero".to_string(),
            });
        }

        let data_file_size_mechanical_limit = get_maximum_data_file_size();
        if max_data_file_size > data_file_size_mechanical_limit {
            return Err(BuildError::InvalidParameter {
                param_name: "max_data_file_size",

View on GitHub (pinned to 3708c39b12)

Solutions

1. No action possible or needed; report upstream if it ever appears

When it happens

Trigger: u64::try_from(DEFAULT_MAX_DATA_FILE_SIZE) failing — impossible since the constant is 128 * 1024 * 1024 and `usize` is at least 32-bit; only a hypothetical >64-bit `usize` target could trip it.

Common situations: None; the value is a compile-time literal.

Related errors

• event count should never exceed u64
• Event count for a record cannot exceed 2^64 events.
• Ledger length cannot be greater than `u64`.
• Vector only supports record sizes that fit in u64
• record was already validated

AI-assisted analysis of vectordotdev/vector@3708c39b12 (2026-08-20). Data as JSON: /api/errors/5102291c2212dfce. Report an issue: GitHub.