systemd.scope(5) — Linux manual page

NAME | SYNOPSIS | DESCRIPTION | AUTOMATIC DEPENDENCIES | OPTIONS | SEE ALSO | NOTES | COLOPHON

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

NAME         top

       systemd.scope - Scope unit configuration

SYNOPSIS         top

       scope.scope

DESCRIPTION         top

       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         top

   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:

       •   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         top

       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 page Control Group v2[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.service(8).
           Similarly to the kernel OOM kills performed by the kernel,
           this setting determines the state of the unit after
           systemd-oomd kills a cgroup associated with it.

           Added in version 253.

       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.

           Added in version 244.

       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.

           Added in version 250.

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

SEE ALSO         top

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

NOTES         top

        1. New Control Group Interfaces
           https://systemd.io/CONTROL_GROUP_INTERFACE

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

COLOPHON         top

       This page is part of the systemd (systemd system and service
       manager) project.  Information about the project can be found at
       ⟨http://www.freedesktop.org/wiki/Software/systemd⟩.  If you have
       a bug report for this manual page, see
       ⟨http://www.freedesktop.org/wiki/Software/systemd/#bugreports⟩.
       This page was obtained from the project's upstream Git repository
       ⟨https://github.com/systemd/systemd.git⟩ on 2024-06-14.  (At that
       time, the date of the most recent commit that was found in the
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       (which is not part of the original manual page), send a mail to
       [email protected]

systemd 257~devel                                       SYSTEMD.SCOPE(5)

Pages that refer to this page: systemd(1)systemd-run(1)environment.d(5)logind.conf(5)systemd.kill(5)systemd.resource-control(5)systemd.slice(5)systemd.unit(5)[email protected](5)systemd.directives(7)systemd.index(7)systemd.syntax(7)pam_systemd(8)