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 the main process of a
           unit has exited or the delay configured via the TimeoutStopSec= has
           passed, 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 247                                                      SYSTEMD.KILL(5)