The B<flush> function connects to L<rrdcached>, the RRD caching daemon, and
issues a "flush" command for the given file. The daemon will put this file to
the head of the update queue so it is written "soon". The status will be
-returned after the node has been B<dequeued> by the update thread. By the time
-execution of this command ends it is very likely that the update thread has
-just updated the requested file, though this is not guaranteed.
+returned only after the file's pending updates have been written to disk.
=over 8
=item B<--daemon> I<address>
-Address of the L<rrdcached> daemon. If not specified, the RRDCACHED_ADDRESS
-environment variable must be set (see below). To specify a UNIX domain socket
-use the prefix C<unix:>, see example below. Other addresses are interpreted as
-normal network addresses, i.E<nbsp>e. IPv4 or IPv6 addresses in most cases.
+Address of the L<rrdcached> daemon. If not specified, the
+RRDCACHED_ADDRESS environment variable must be set (see below). For a
+list of accepted formats, see the B<-l> option in the L<rrdcached>
+manual.
rrdtool flush --daemon unix:/var/run/rrdcached.sock /var/lib/rrd/foo.rrd