following:</para>
<programlisting>/bin/kill -HUP $MAINPID</programlisting>
+
+ <para>Note however that reloading a
+ daemon by sending a signal (as with
+ the example line above) is usually not
+ a good choice, because this is an
+ asynchronous operation and hence not
+ suitable to order reloads of multiple
+ services against each other. It is
+ strongly recommended to set
+ <varname>ExecReload=</varname> to a
+ command that not only triggers a
+ configuration reload of the daemon,
+ but also synchronously waits for it to
+ complete.</para>
</listitem>
</varlistentry>
<option>no</option>,
<option>on-success</option>,
<option>on-failure</option>,
+ <option>on-abnormal</option>,
<option>on-watchdog</option>,
<option>on-abort</option>, or
<option>always</option>. If set to
<option>no</option> (the default), the
- service will not be restarted. If set to
- <option>on-success</option>, it will be
- restarted only when the service process
- exits cleanly.
- In this context, a clean exit means
- an exit code of 0, or one of the signals
+ service will not be restarted. If set
+ to <option>on-success</option>, it
+ will be restarted only when the
+ service process exits cleanly. In
+ this context, a clean exit means an
+ exit code of 0, or one of the signals
<constant>SIGHUP</constant>,
<constant>SIGINT</constant>,
- <constant>SIGTERM</constant>,
- or <constant>SIGPIPE</constant>, and
- additionally, exit statuses and signals
- specified in <varname>SuccessExitStatus=</varname>.
+ <constant>SIGTERM</constant> or
+ <constant>SIGPIPE</constant>, and
+ additionally, exit statuses and
+ signals specified in
+ <varname>SuccessExitStatus=</varname>.
If set to <option>on-failure</option>,
the service will be restarted when the
- process exits with a non-zero exit code,
- is terminated by a signal (including on
- core dump), when an operation (such as
- service reload) times out, and when the
- configured watchdog timeout is triggered.
- If set to
- <option>on-abort</option>, the service
- will be restarted only if the service
- process exits due to an uncaught
- signal not specified as a clean exit
- status.
- If set to
- <option>on-watchdog</option>, the service
- will be restarted only if the watchdog
- timeout for the service expires.
- If set to
+ process exits with a non-zero exit
+ code, is terminated by a signal
+ (including on core dump, but excluding
+ the aforementiond four signals), when
+ an operation (such as service reload)
+ times out, and when the configured
+ watchdog timeout is triggered. If set
+ to <option>on-abnormal</option>, the
+ service will be restarted when the
+ process is terminated by a signal
+ (including on core dump, excluding the
+ aforementioned four signals), when an
+ operation times out, or when the
+ watchdog timeout is triggered. If set
+ to <option>on-abort</option>, the
+ service will be restarted only if the
+ service process exits due to an
+ uncaught signal not specified as a
+ clean exit status. If set to
+ <option>on-watchdog</option>, the
+ service will be restarted only if the
+ watchdog timeout for the service
+ expires. If set to
<option>always</option>, the service
- will be restarted regardless of whether
- it exited cleanly or not, got
+ will be restarted regardless of
+ whether it exited cleanly or not, got
terminated abnormally by a signal, or
hit a timeout.</para>
+ <table>
+ <title>Exit causes and the effect of the <varname>Restart=</varname> settings on them</title>
+
+ <tgroup cols='2'>
+ <colspec colname='path' />
+ <colspec colname='expl' />
+ <thead>
+ <row>
+ <entry>Restart settings/Exit causes</entry>
+ <entry><option>no</option></entry>
+ <entry><option>always</option></entry>
+ <entry><option>on-success</option></entry>
+ <entry><option>on-failure</option></entry>
+ <entry><option>on-abnormal</option></entry>
+ <entry><option>on-abort</option></entry>
+ <entry><option>on-watchdog</option></entry>
+ </row>
+ </thead>
+ <tbody>
+ <row>
+ <entry>Clean exit code or signal</entry>
+ <entry/>
+ <entry>X</entry>
+ <entry>X</entry>
+ <entry/>
+ <entry/>
+ <entry/>
+ <entry/>
+ </row>
+ <row>
+ <entry>Unclean exit code</entry>
+ <entry/>
+ <entry>X</entry>
+ <entry/>
+ <entry>X</entry>
+ <entry/>
+ <entry/>
+ <entry/>
+ </row>
+ <row>
+ <entry>Unclean signal</entry>
+ <entry/>
+ <entry>X</entry>
+ <entry/>
+ <entry>X</entry>
+ <entry>X</entry>
+ <entry>X</entry>
+ <entry/>
+ </row>
+ <row>
+ <entry>Timeout</entry>
+ <entry/>
+ <entry>X</entry>
+ <entry/>
+ <entry>X</entry>
+ <entry>X</entry>
+ <entry/>
+ <entry/>
+ </row>
+ <row>
+ <entry>Watchdog</entry>
+ <entry/>
+ <entry>X</entry>
+ <entry/>
+ <entry>X</entry>
+ <entry>X</entry>
+ <entry/>
+ <entry>X</entry>
+ </row>
+ </tbody>
+ </tgroup>
+ </table>
+
<para>In addition to the above settings,
the service will not be restarted if the
exit code or signal is specified in
<varname>RestartPreventExitStatus=</varname>
- (see below).</para></listitem>
+ (see below).</para>
+
+ <para>Setting this to
+ <option>on-failure</option> is the
+ recommended choice for long-running
+ services, in order to increase
+ reliability by attempting automatic
+ recovery from errors. For services
+ that shall be able to terminate on
+ their own choice (and avoiding
+ immediate restart),
+ <option>on-abnormal</option> is an
+ alternative choice.</para>
+ </listitem>
</varlistentry>
<varlistentry>
~ianmdlvl / elogind.git / blobdiff