> ## 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.

# connect_timeout_* session settings

> ClickHouse session settings in the connect_timeout_* 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="connect_timeout">
  connect\_timeout
</h2>

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

Connection timeout if there are no replicas.

<h2 id="connect_timeout_with_failover_ms">
  connect\_timeout\_with\_failover\_ms
</h2>

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

<VersionHistory rows={[{"id": "row-1","items": [{"label": "23.4"},{"label": "1000"},{"label": "Increase default connect timeout because of async connect"}]}]} />

The timeout in milliseconds for connecting to a remote server for a Distributed table engine, if the 'shard' and 'replica' sections are used in the cluster definition.
If unsuccessful, several attempts are made to connect to various replicas.

<h2 id="connect_timeout_with_failover_secure_ms">
  connect\_timeout\_with\_failover\_secure\_ms
</h2>

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

<VersionHistory rows={[{"id": "row-1","items": [{"label": "23.4"},{"label": "1000"},{"label": "Increase default secure connect timeout because of async connect"}]}]} />

Connection timeout for selecting first healthy replica (for secure connections).