[Date Prev][Date Next] [Thread Prev][Thread Next] [Date Index] [Thread Index]

Bug#1004862: marked as done (neglected note in dist-upgrade documentation, section 4)

Your message dated Sun, 29 Jan 2023 21:27:04 +0100
with message-id <df16a285-3636-8b75-9e09-47b95bc7a4d1@debian.org>
and subject line Re: neglected note in dist-upgrade documentation, section 4
has caused the Debian Bug report #1004862,
regarding neglected note in dist-upgrade documentation, section 4
to be marked as done.

This means that you claim that the problem has been dealt with.
If this is not the case it is now your responsibility to reopen the
Bug report if necessary, and/or fix the problem forthwith.

(NB: If you are a system administrator and have no idea what this
message is talking about, this may indicate a serious mail system
misconfiguration somewhere. Please contact owner@bugs.debian.org
immediately.)


-- 
1004862: https://bugs.debian.org/cgi-bin/bugreport.cgi?bug=1004862
Debian Bug Tracking System
Contact owner@bugs.debian.org with problems
--- Begin Message --- 
Package: apt-get
Version: any


Hi,


Package apt-get is a placeholder for
https://www.debian.org/releases/stable/amd64/release-notes/ch-upgrading.en.html#backup
as it's with apt-get dist-upgrade that the potential problem manifests.

The problem scenario is as such:
Some services have the task of keeping services running. Specific
service in this case is "monit" from package "monit": It periodically
probes whether selected services still respond, and takes action if
they don't. The exact nature of the response (as, the command for
restarting a service) is user configurable, per service. monit comes
with a set of preconfigured rules to restart common services.

The problem arises when apt-get dist-upgrade stops services, prior to
upgrading them. During that time is it possible that the monit probe
takes place, and monit detects a stopped service, consequently taking
actions to restart it. This may conflict and potentially sabotage
apt-get's attempt to upgrade a package.

As it seems that Debian has no provisions to deal with this potential
problem, a clarification in
https://www.debian.org/releases/stable/amd64/release-notes/ch-upgrading.en.html#backup
may be helpful, adding the suggestion to stop services such as monit
prior to dist-upgrade.

Observed today when dist-upgrading from oldstable to stable, when
multiple services were restarted by monit while upgrading those wasn't
yet complete.

Real fix in this case may be to ask monit maintainers to take care of
the default service restarting scripts in a way that this described
scenario won't occur - but there exist more of such services, therefore
this potential problem may not be specific to monit. And still, as the
actions are user-configurable, a simple /etc/init.d/foo start or
service foo start  as configured restart command may not catch the
situation of a dist-upgrade running.

So I think it may be, for now, merely a documentation issue: ask folks
to stop such a service prior to dist-upgrade.

Thank you.
L.Schmidt

Attachment: pgpu37nMuPXOy.pgp
Description: Digitale Signatur von OpenPGP


--- End Message ---
--- Begin Message --- 
Hi,

On 18-12-2022 21:06, Paul Gevers wrote:

How does the following look?

diff --git a/en/upgrading.dbk b/en/upgrading.dbk
index 75438d31..e2107bad 100644
--- a/en/upgrading.dbk
+++ b/en/upgrading.dbk
@@ -1006,6 +1006,18 @@ E: You don't have enough free space in /var/cache/apt/archives/. 
      </para>
    </section>

+  <section id="stop-monitoring-systems">
+    <title>Stop monitoring systems</title>
+    <para>
+      As <command>apt</command> may need to temporarily stop services
+      running on your computer, it's probably a good idea to stop
+      monitoring services that can restart other terminated services
+      during the upgrade. In Debian, <systemitem
+      role="package">monit</systemitem> is an example of such a
+      service.
+    </para>
+  </section>
+
    <section id="minimal-upgrade">
      <title>Minimal system upgrade</title>
      <para>


I just pushed this change.

Paul

Attachment: OpenPGP_signature
Description: OpenPGP digital signature


--- End Message ---
Reply to: