F38 proposal: Shorter Shutdown Timer (System-Wide Change proposal)

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https://fedoraproject.org/wiki/Changes/Shorter_Shutdown_Timer

This document represents a proposed Change. As part of the Changes
process, proposals are publicly announced in order to receive
community feedback. This proposal will only be implemented if approved
by the Fedora Engineering Steering Committee.

== Summary ==
A downstream configuration change to reduce the systemd unit timeout
from 2 minutes to 15 seconds.

== Owner ==
* Name: catanzaro
* Email: mcatanzaro at redhat dot com
* Name: aday
* Email: aday at redhat dot com


== Detailed Description ==
Currently, a service that fails to stop at shutdown time can block
shutdown for up to 2 minutes. This is extremely frustrating for our
users - someone goes to shutdown or reboot their system, and then
unexpectedly has to wait for a long time before they can do anything
else.

The most common service to cause this issue is PackageKit, but there are others.

When a service fails to shutdown when it is instructed to do so, it is
not behaving properly, and it is preventing the system from behaving
in an orderly and predictable manner. Desktop APIs exist for cases
when services or apps legitimately need to prevent shutdown, and these
allow the shutdown inhibit to be communicated to admins and users, so
they understand what is happening. When the user decides to shut down
anyway, services must terminate in a timely manner. The Workstation
Working Group feels that 15 seconds is the maximum appropriate time
for both system and user services, and that Fedora should be robust to
buggy and misbehaving services that do not shut down in an appropriate
manner.

=== History ===

The Workstation Working Group has been
[https://pagure.io/fedora-workstation/issue/163 working on this issue
for several years]. Investigations have revealed that it's not
possible to fix every misbehaving service: in some cases the
misbehaviour comes from design flaws that are difficult to resolve.

An attempt has also been
[https://github.com/systemd/systemd/pull/18386 made to have the unit
timeout changed in upstream systemd]. That attempt did not go
anywhere, despite various efforts to move it along. We are no longer
comfortable waiting for upstream changes to land.

To our knowledge, there are no issues that will result from forcing
services to stop after 15 seconds on typical systems. However, system
administrators may need to configure a higher timeout if waiting
longer for a particular service, which may be true for database
services, for example.

== Feedback ==
The relevant [https://pagure.io/fedora-workstation/issue/163
Workstation Working Group ticket] includes some discussion. This
change [https://pagure.io/fesco/issue/2853 was also previously
proposed to FESCo].

== Benefit to Fedora ==
The primary benefit of the change will be to mitigate a very annoying
and - frankly - embarrassing bug. Our users shouldn't have to randomly
sit waiting for their machine to shutdown. It will also encourage the
correct use of shutdown inhibit APIs.

Although this change will "paper over" bugs in services without fixing
them, we emphasize that reducing the timeout is not merely a
workaround for buggy services, but also the desired permanent design.
Of course it is desirable to fix the underlying bugs as well, but it
doesn't make sense to require this before fixing the service timeout
to match our needs.

== Scope ==
* Proposal owners:
** Merge [https://src.fedoraproject.org/rpms/systemd/pull-request/85
the downstream change] to {{package|systemd}}.
* Other developers:
** Test their packages with the new behavior and report issues as necessary.
* Release engineering: [https://pagure.io/releng/issue/11193 #11193]
* Policies and guidelines: No policy or guideline changes required
* Trademark approval: N/A (not needed for this Change)
* Alignment with Objectives:

== Upgrade/compatibility impact ==
System and user services will be killed with SIGKILL 15 seconds after
receiving SIGTERM, from previously 1 minute 30 seconds for most system
and user services, or 2 minutes for user manager system services (the
system service that runs all user services for a user), so services
will have less time to shut down gracefully by default. These defaults
are configurable and system administrators who require longer timeouts
would need to adjust them before or after upgrade. You may edit the
DefaultTimeoutStopSec= setting in /etc/systemd/user.conf and
/etc/systemd/system.conf. You may also create a drop-in to change the
TimeoutStopSec= setting for user@service.

== How To Test ==
Given the intermittent and unpredictable nature of the bug that is
being targeted, the best way to test is by using the upcoming Fedora
release. Are shutdown delays eliminated as intended? Do system
services experience issues as a result of the change?

== User Experience ==
This change will make the Fedora user experience less annoying. It
will also encourage the use of the existing inhibit APIs, which
provide better feedback for users when system shutdown does need to be
delayed.

== Dependencies ==
No specific changes are required in other packages. However, service
developers may want to take this opportunity to examine the shutdown
behavior of their components.

== Contingency Plan ==
* Contingency mechanism: the change owners will revert the change in systemd.
* Contingency deadline: if we back out the change it would be best to
do it before beta freeze, but this can happen at any point.
* Blocks release? No.

== Documentation ==
Documentation isn't required for this minor configuration change.
Services that legitimately need to prevent system shutdown should use
[https://www.freedesktop.org/wiki/Software/systemd/inhibit/ systemd
inhibit]. Desktop applications can use the
[https://flatpak.github.io/xdg-desktop-portal/#gdbus-org.freedesktop.portal.Inhibit
XDG inhibit portal].

== Release Notes ==


-- 
Ben Cotton
He / Him / His
Fedora Program Manager
Red Hat
TZ=America/Indiana/Indianapolis
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