man 5 SYSTEMD.SCOPE

SYSTEMD.SCOPE(5)                 systemd.scope                SYSTEMD.SCOPE(5)

NAME
       systemd.scope - Scope unit configuration

SYNOPSIS
       scope.scope

DESCRIPTION
       Scope units are not configured via unit configuration files, but are
       only created programmatically using the bus interfaces of systemd. They
       are named similar to filenames. A unit whose name ends in ".scope"
       refers to a scope unit. Scopes units manage a set of system processes.
       Unlike service units, scope units manage externally created processes,
       and do not fork off processes on its own.

       The main purpose of scope units is grouping worker processes of a
       system service for organization and for managing resources.

       systemd-run --scope may be used to easily launch a command in a new
       scope unit from the command line.

       See the New Control Group Interfaces[1] for an introduction on how to
       make use of scope units from programs.

       Note that, unlike service units, scope units have no "main" process:
       all processes in the scope are equivalent. The lifecycle of the scope
       unit is thus not bound to the lifetime of one specific process, but to
       the existence of at least one process in the scope. This also means
       that the exit statuses of these processes are not relevant for the
       scope unit failure state. Scope units may still enter a failure state,
       for example due to resource exhaustion or stop timeouts being reached,
       but not due to programs inside of them terminating uncleanly. Since
       processes managed as scope units generally remain children of the
       original process that forked them off, it is also the job of that
       process to collect their exit statuses and act on them as needed.

AUTOMATIC DEPENDENCIES
   Implicit Dependencies
       Implicit dependencies may be added as result of resource control
       parameters as documented in systemd.resource-control(5).

   Default Dependencies
       The following dependencies are added unless DefaultDependencies=no is
       set:

       o   Scope units will automatically have dependencies of type Conflicts=
           and Before= on shutdown.target. These ensure that scope units are
           removed prior to system shutdown. Only scope units involved with
           early boot or late system shutdown should disable
           DefaultDependencies= option.

OPTIONS
       Scope files may include a [Unit] section, which is described in
       systemd.unit(5).

       Scope files may include a [Scope] section, which carries information
       about the scope and the units it contains. A number of options that may
       be used in this section are shared with other unit types. These options
       are documented in systemd.kill(5) and systemd.resource-control(5). The
       options specific to the [Scope] section of scope units are the
       following:

       OOMPolicy=
           Configure the out-of-memory (OOM) killing policy for the kernel and
           the userspace OOM killer systemd-oomd.service(8). On Linux, when
           memory becomes scarce to the point that the kernel has trouble
           allocating memory for itself, it might decide to kill a running
           process in order to free up memory and reduce memory pressure. Note
           that systemd-oomd.service is a more flexible solution that aims to
           prevent out-of-memory situations for the userspace too, not just
           the kernel, by attempting to terminate services earlier, before the
           kernel would have to act.

           This setting takes one of continue, stop or kill. If set to
           continue and a process in the unit is killed by the OOM killer,
           this is logged but the unit continues running. If set to stop the
           event is logged but the unit is terminated cleanly by the service
           manager. If set to kill and one of the unit's processes is killed
           by the OOM killer the kernel is instructed to kill all remaining
           processes of the unit too, by setting the memory.oom.group
           attribute to 1; also see kernel documentation[2].

           Defaults to the setting DefaultOOMPolicy= in systemd-system.conf(5)
           is set to, except for units where Delegate= is turned on, where it
           defaults to continue.

           Use the OOMScoreAdjust= setting to configure whether processes of
           the unit shall be considered preferred or less preferred candidates
           for process termination by the Linux OOM killer logic. See
           systemd.exec(5) for details.

           This setting also applies to systemd-oomd. Similarly to the kernel
           OOM kills, this setting determines the state of the unit after
           systemd-oomd kills a cgroup associated with it.

       RuntimeMaxSec=
           Configures a maximum time for the scope to run. If this is used and
           the scope has been active for longer than the specified time it is
           terminated and put into a failure state. Pass "infinity" (the
           default) to configure no runtime limit.

       RuntimeRandomizedExtraSec=
           This option modifies RuntimeMaxSec= by increasing the maximum
           runtime by an evenly distributed duration between 0 and the
           specified value (in seconds). If RuntimeMaxSec= is unspecified,
           then this feature will be disabled.

       Check systemd.unit(5), systemd.exec(5), and systemd.kill(5) for more
       settings.

SEE ALSO
       systemd(1), systemd-run(1), systemd.unit(5), systemd.resource-
       control(5), systemd.service(5), systemd.directives(7).

NOTES
        1. New Control Group Interfaces
           https://www.freedesktop.org/wiki/Software/systemd/ControlGroupInterface

        2. kernel documentation
           https://docs.kernel.org/admin-guide/cgroup-v2.html

systemd 252                                                   SYSTEMD.SCOPE(5)