> ## Documentation Index
> Fetch the complete documentation index at: https://clickhouse.com/docs/llms.txt
> Use this file to discover all available pages before exploring further.

# http_headers_* session settings

> ClickHouse session settings in the http_headers_* generated group.

export const SettingsInfoBlock = ({type, default_value, changeable_without_restart}) => {
  return <div className="not-prose" style={{
    display: "flex",
    flexWrap: "wrap",
    alignItems: "baseline",
    columnGap: "0.5rem",
    rowGap: "0.125rem",
    margin: "0.375rem 0",
    fontSize: "0.8125rem",
    lineHeight: "1.125rem"
  }}>
      <div style={{
    fontWeight: 600,
    opacity: 0.72
  }}>Type</div>
      <div style={{
    overflowWrap: "anywhere"
  }}>{type}</div>
      <div style={{
    fontWeight: 600,
    opacity: 0.72,
    marginInlineStart: "0.5rem"
  }}>Default</div>
      <div style={{
    overflowWrap: "anywhere"
  }}>{default_value}</div>
      {changeable_without_restart && <div style={{
    fontWeight: 600,
    opacity: 0.72,
    marginInlineStart: "0.5rem"
  }}>
          Changeable without restart
        </div>}
      {changeable_without_restart && <div style={{
    overflowWrap: "anywhere"
  }}>
          {changeable_without_restart}
        </div>}
    </div>;
};

These settings are available in [system.settings](/docs/reference/system-tables/settings) and are autogenerated from [source](https://github.com/ClickHouse/ClickHouse/blob/master/src/Core/Settings.cpp).

<h2 id="http_headers_progress_interval_ms">
  http\_headers\_progress\_interval\_ms
</h2>

<SettingsInfoBlock type="UInt64" default_value="100" />

Do not send HTTP headers X-ClickHouse-Progress more frequently than at each specified interval.

<h2 id="http_headers_read_timeout">
  http\_headers\_read\_timeout
</h2>

<SettingsInfoBlock type="Seconds" default_value="30" />

<VersionHistory rows={[{"id": "row-1","items": [{"label": "26.4"},{"label": "30"},{"label": "New setting to limit total time for reading HTTP request headers, protecting against slowloris attacks."}]}]} />

Maximum time in seconds to read all HTTP request headers. This is a total deadline for the entire header parsing phase, not a per-read timeout. Protects against slowloris-style attacks where a client trickles header data slowly to hold connections open.