the operating system should send a TCP keepalive message to the client.

If this value is specified without units, it is taken as seconds.

A value of 0 (the default) selects the operating system's default.

On Windows, setting a value of 0 will set this parameter to 2 hours,

since Windows does not provide a way to read the system default value.

This parameter is supported only on systems that support

<symbol>TCP_KEEPIDLE</symbol> or an equivalent socket option, and on

Windows; on other systems, it must be zero.

In sessions connected via a Unix-domain socket, this parameter is

ignored and always reads as zero.

</para>

<note>

<para>

On Windows, setting a value of 0 will set this parameter to 2 hours,

since Windows does not provide a way to read the system default value.

</para>

</note>

</listitem>

</varlistentry>

that has not been acknowledged by the client should be retransmitted.

If this value is specified without units, it is taken as seconds.

A value of 0 (the default) selects the operating system's default.

On Windows, setting a value of 0 will set this parameter to 1 second,

since Windows does not provide a way to read the system default value.

This parameter is supported only on systems that support

<symbol>TCP_KEEPINTVL</symbol> or an equivalent socket option, and on

Windows; on other systems, it must be zero.

In sessions connected via a Unix-domain socket, this parameter is

ignored and always reads as zero.

</para>

<note>

<para>

On Windows, setting a value of 0 will set this parameter to 1 second,

since Windows does not provide a way to read the system default value.

</para>

</note>

</listitem>

</varlistentry>

the server's connection to the client is considered dead.

A value of 0 (the default) selects the operating system's default.

This parameter is supported only on systems that support

<symbol>TCP_KEEPCNT</symbol> or an equivalent socket option;

<symbol>TCP_KEEPCNT</symbol> or an equivalent socket option (which does not include Windows);

on other systems, it must be zero.

In sessions connected via a Unix-domain socket, this parameter is

ignored and always reads as zero.

</para>

<note>

<para>

This parameter is not supported on Windows, and must be zero.

</para>

</note>

</listitem>

</varlistentry>

If this value is specified without units, it is taken as milliseconds.

A value of 0 (the default) selects the operating system's default.

This parameter is supported only on systems that support

<symbol>TCP_USER_TIMEOUT</symbol>; on other systems, it must be zero.

<symbol>TCP_USER_TIMEOUT</symbol> (which does not include Windows); on other systems, it must be zero.

In sessions connected via a Unix-domain socket, this parameter is

ignored and always reads as zero.

</para>

<note>

<para>

This parameter is not supported on Windows, and must be zero.

</para>

</note>

</listitem>

</varlistentry>