> ## 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_max_* session settings

> ClickHouse session settings in the http_max_* 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_max_field_name_size">
  http\_max\_field\_name\_size
</h2>

<SettingsInfoBlock type="UInt64" default_value="4096" />

<VersionHistory rows={[{"id": "row-1","items": [{"label": "26.4"},{"label": "4096"},{"label": "Reduce default to limit pre-authentication memory usage by HTTP connections."}]}]} />

Maximum length of a field name in HTTP request headers, query parameters, and form data.

<h2 id="http_max_field_value_size">
  http\_max\_field\_value\_size
</h2>

<SettingsInfoBlock type="UInt64" default_value="131072" />

Maximum length of a field value in HTTP request headers, query parameters, and form data.

<h2 id="http_max_fields">
  http\_max\_fields
</h2>

<SettingsInfoBlock type="UInt64" default_value="1000" />

<VersionHistory rows={[{"id": "row-1","items": [{"label": "26.4"},{"label": "1000"},{"label": "Reduce default to limit pre-authentication memory usage by HTTP connections."}]}]} />

Maximum number of fields in HTTP request headers, query parameters, and form data.

<h2 id="http_max_multipart_form_data_size">
  http\_max\_multipart\_form\_data\_size
</h2>

<SettingsInfoBlock type="UInt64" default_value="1073741824" />

Limit on size of multipart/form-data content. This setting cannot be parsed from URL parameters and should be set in a user profile. Note that content is parsed and external tables are created in memory before the start of query execution. And this is the only limit that has an effect on that stage (limits on max memory usage and max execution time have no effect while reading HTTP form data).

<h2 id="http_max_request_header_size">
  http\_max\_request\_header\_size
</h2>

<SettingsInfoBlock type="UInt64" default_value="10485760" />

<VersionHistory rows={[{"id": "row-1","items": [{"label": "26.4"},{"label": "10485760"},{"label": "New setting to limit total HTTP request header size before authentication."}]}]} />

Maximum total size of all HTTP request headers (names and values combined) in bytes.

<h2 id="http_max_request_param_data_size">
  http\_max\_request\_param\_data\_size
</h2>

<SettingsInfoBlock type="UInt64" default_value="10485760" />

Limit on size of request data used as a query parameter in predefined HTTP requests.

<h2 id="http_max_tries">
  http\_max\_tries
</h2>

<SettingsInfoBlock type="UInt64" default_value="10" />

Max attempts to read via http.

<h2 id="http_max_uri_size">
  http\_max\_uri\_size
</h2>

<SettingsInfoBlock type="UInt64" default_value="1048576" />

Sets the maximum URI length of an HTTP request.

Possible values:

* Positive integer.