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<chapter id="libpq">

<title><application>libpq</application> - C Library</title>

<term><literal>keepalives</literal></term>

<listitem>

<para>

Controls whether TCP keepalives are used. The default value is 1,

meaning on, but you can change this to 0, meaning off, if keepalives

are not wanted. This parameter is ignored for connections made via

a Unix-domain socket.

Controls whetherclient-sideTCP keepalives are used. The default

value is 1,meaning on, but you can change this to 0, meaning off,

if keepalivesare not wanted. This parameter is ignored for

connections made viaa Unix-domain socket.

</para>

</listitem>

</varlistentry>

<term><literal>keepalives_idle</literal></term>

<listitem>

<para>

On systems that support the <symbol>TCP_KEEPIDLE</symbol> socket

option, specifies the number of seconds between sending keepalives

on an otherwise idle connection. A value of zero uses the system

default. This parameter is ignored for connections made via a

Unix-domain socket, or if keepalives are disabled.

Controls the number of seconds of inactivity after which TCP should

send a keepalive message to the server. A value of zero uses the

system default. This parameter is ignored if the

<symbol>TCP_KEEPIDLE</> socket option is not supported, for

connections made via a Unix-domain socket, or if keepalives are

disabled.

</para>

</listitem>

</varlistentry>

<term><literal>keepalives_interval</literal></term>

<listitem>

<para>

On systems that support the <symbol>TCP_KEEPINTVL</symbol> socket

option, specifies how long, in seconds, to wait for a response to a

keepalive before retransmitting. A value of zero uses the system

default. This parameter is ignored for connections made via a

Unix-domain socket, or if keepalives are disabled.

Controls the number of seconds after which a TCP keepalive message

that is not acknowledged by the server should be retransmitted. A

value of zero uses the system default. This parameter is ignored if

the <symbol>TCP_KEEPINTVL</> socket option is not supported, for

connections made via a Unix-domain socket, or if keepalives are

disabled.

</para>

</listitem>

</varlistentry>

<term><literal>keepalives_count</literal></term>

<listitem>

<para>

On systems that support the <symbol>TCP_KEEPCNT</symbol> socket

option, specifies how many keepalives can be lost before the

connection is considered dead. A value of zero uses the system

default. This parameter is ignored for connections made via a

Unix-domain socket, or if keepalives are disabled.

Controls the number of TCP keepalives that can be lost before the

client's connection to the server is considered dead. A value of

zero uses the system default. This parameter is ignored if the

<symbol>TCP_KEEPCNT</> socket option is not supported, for

connections made via a Unix-domain socket, or if keepalives are

disabled.

</para>

</listitem>

</varlistentry>