Unlike the WAL receiver of a PostgreSQL standby server, <application>pg_receivewal</>

by default flushes WAL data only when a WAL file is closed.

The option <option>--synchronous</> must be specified to flush WAL data

in real time.

in real time. Since <application>pg_receivewal</application> does not

apply WAL, you should not allow it to become a synchronous standby when

<xref linkend="guc-synchronous-commit"/> equals

<literal>remote_apply</literal>. If it does, it will appear to be a

standby that never catches up, and will cause transaction commits to

block. To avoid this, you should either configure an appropriate value

for <xref linkend="guc-synchronous-standby-names"/>, or specify

<varname>application_name</varname> for

<application>pg_receivewal</application> that does not match it, or

change the value of <varname>synchronous_commit</varname> to

something other than <literal>remote_apply</literal>.

</para>

<para>