Copyright 2010 Lennart Poettering
systemd is free software; you can redistribute it and/or modify it
- under the terms of the GNU General Public License as published by
- the Free Software Foundation; either version 2 of the License, or
+ under the terms of the GNU Lesser General Public License as published by
+ the Free Software Foundation; either version 2.1 of the License, or
(at your option) any later version.
systemd is distributed in the hope that it will be useful, but
WITHOUT ANY WARRANTY; without even the implied warranty of
MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
- General Public License for more details.
+ Lesser General Public License for more details.
- You should have received a copy of the GNU General Public License
+ You should have received a copy of the GNU Lesser General Public License
along with systemd; If not, see <http://www.gnu.org/licenses/>.
-->
<term>WATCHDOG=1</term>
<listitem><para>Tells systemd to
- update the watchdog timestamp.
- Services using this feature should do
- this in regular intervals. A watchdog
- framework can use the timestamps to
- detect failed
- services.</para></listitem>
+ update the watchdog timestamp. This is
+ the keep-alive ping that services need
+ to issue in regular intervals if
+ <varname>WatchdogSec=</varname> is
+ enabled for it. See
+ <citerefentry><refentrytitle>systemd.service</refentrytitle><manvolnum>5</manvolnum></citerefentry>
+ for details. It is recommended to send
+ this message if the
+ <varname>WATCHDOG_USEC=</varname>
+ environment variable has been set for
+ the service process, in every half the
+ time interval that is specified in the
+ variable.</para></listitem>
</varlistentry>
</variablelist>
<para>For details about the algorithms check the
liberally licensed reference implementation sources:
- <ulink url="http://cgit.freedesktop.org/systemd/plain/src/sd-daemon.c"/>
+ <ulink url="http://cgit.freedesktop.org/systemd/systemd/plain/src/sd-daemon.c"/>
resp. <ulink
- url="http://cgit.freedesktop.org/systemd/plain/src/systemd/sd-daemon.h"/></para>
+ url="http://cgit.freedesktop.org/systemd/systemd/plain/src/systemd/sd-daemon.h"/></para>
<para><function>sd_notify()</function> and
<function>sd_notifyf()</function> are implemented in