man 5 SYSTEMD.KILL

SYSTEMD.KILL(5)                  systemd.kill                  SYSTEMD.KILL(5)

NAME
       systemd.kill - Process killing procedure configuration

SYNOPSIS
       service.service, socket.socket, mount.mount, swap.swap, scope.scope

DESCRIPTION
       Unit configuration files for services, sockets, mount points, swap
       devices and scopes share a subset of configuration options which define
       the killing procedure of processes belonging to the unit.

       This man page lists the configuration options shared by these five unit
       types. See systemd.unit(5) for the common options shared by all unit
       configuration files, and systemd.service(5), systemd.socket(5),
       systemd.swap(5), systemd.mount(5) and systemd.scope(5) for more
       information on the configuration file options specific to each unit
       type.

       The kill procedure configuration options are configured in the
       [Service], [Socket], [Mount] or [Swap] section, depending on the unit
       type.

OPTIONS
       KillMode=
           Specifies how processes of this unit shall be killed. One of
           control-group, mixed, process, none.

           If set to control-group, all remaining processes in the control
           group of this unit will be killed on unit stop (for services: after
           the stop command is executed, as configured with ExecStop=). If set
           to mixed, the SIGTERM signal (see below) is sent to the main
           process while the subsequent SIGKILL signal (see below) is sent to
           all remaining processes of the unit's control group. If set to
           process, only the main process itself is killed (not recommended!).
           If set to none, no process is killed (strongly recommended
           against!). In this case, only the stop command will be executed on
           unit stop, but no process will be killed otherwise. Processes
           remaining alive after stop are left in their control group and the
           control group continues to exist after stop unless empty.

           Note that it is not recommended to set KillMode= to process or even
           none, as this allows processes to escape the service manager's
           lifecycle and resource management, and to remain running even while
           their service is considered stopped and is assumed to not consume
           any resources.

           Processes will first be terminated via SIGTERM (unless the signal
           to send is changed via KillSignal= or RestartKillSignal=).
           Optionally, this is immediately followed by a SIGHUP (if enabled
           with SendSIGHUP=). If processes still remain after:

           o   the main process of a unit has exited (applies to KillMode=:
               mixed)

           o   the delay configured via the TimeoutStopSec= has passed
               (applies to KillMode=: control-group, mixed, process)

           the termination request is repeated with the SIGKILL signal or the
           signal specified via FinalKillSignal= (unless this is disabled via
           the SendSIGKILL= option). See kill(2) for more information.

           Defaults to control-group.

       KillSignal=
           Specifies which signal to use when stopping a service. This
           controls the signal that is sent as first step of shutting down a
           unit (see above), and is usually followed by SIGKILL (see above and
           below). For a list of valid signals, see signal(7). Defaults to
           SIGTERM.

           Note that, right after sending the signal specified in this
           setting, systemd will always send SIGCONT, to ensure that even
           suspended tasks can be terminated cleanly.

       RestartKillSignal=
           Specifies which signal to use when restarting a service. The same
           as KillSignal= described above, with the exception that this
           setting is used in a restart job. Not set by default, and the value
           of KillSignal= is used.

       SendSIGHUP=
           Specifies whether to send SIGHUP to remaining processes immediately
           after sending the signal configured with KillSignal=. This is
           useful to indicate to shells and shell-like programs that their
           connection has been severed. Takes a boolean value. Defaults to
           "no".

       SendSIGKILL=
           Specifies whether to send SIGKILL (or the signal specified by
           FinalKillSignal=) to remaining processes after a timeout, if the
           normal shutdown procedure left processes of the service around.
           When disabled, a KillMode= of control-group or mixed service will
           not restart if processes from prior services exist within the
           control group. Takes a boolean value. Defaults to "yes".

       FinalKillSignal=
           Specifies which signal to send to remaining processes after a
           timeout if SendSIGKILL= is enabled. The signal configured here
           should be one that is not typically caught and processed by
           services (SIGTERM is not suitable). Developers can find it useful
           to use this to generate a coredump to troubleshoot why a service
           did not terminate upon receiving the initial SIGTERM signal. This
           can be achieved by configuring LimitCORE= and setting
           FinalKillSignal= to either SIGQUIT or SIGABRT. Defaults to SIGKILL.

       WatchdogSignal=
           Specifies which signal to use to terminate the service when the
           watchdog timeout expires (enabled through WatchdogSec=). Defaults
           to SIGABRT.

SEE ALSO
       systemd(1), systemctl(1), journalctl(1), systemd.unit(5),
       systemd.service(5), systemd.socket(5), systemd.swap(5),
       systemd.mount(5), systemd.exec(5), systemd.directives(7), kill(2),
       signal(7)

systemd 252                                                    SYSTEMD.KILL(5)