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A call for votes in the Debian init system discussion

A call for votes in the Debian init system discussion

Posted Jan 27, 2014 1:37 UTC (Mon) by nirbheek (subscriber, #54111)
In reply to: A call for votes in the Debian init system discussion by jspaleta
Parent article: A call for votes in the Debian init system discussion

In the interests of documentation, and to make your own argument stronger, it would be nice to have a list of these bug reports and comments so that uninitiated people like me can follow along. Thanks!


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A call for votes in the Debian init system discussion

Posted Jan 27, 2014 6:32 UTC (Mon) by jspaleta (subscriber, #50639) [Link]

As requested:

bug report indicated that conditional event parsing does not work as expected. Upstart lets you build event conditional statements like start on A and B or (C and D) but they do not work. Such constructions are considered valid syntax for job files...but they do not work as one would plainly expect them to.
https://bugs.launchpad.net/upstart/+bug/447654
Scott, as maintainer at the time, comments about "...event operator stuff being utterly broken..."

bug report indicating in embedded scriplets logic result in jobs not restarting when requested to.
https://bugs.launchpad.net/ubuntu/+source/upstart/+bug/70...
Scott has a terse comment concerning lack of pre-stop coverage.

A pathelogical pre-stop bug report that Scott filed. This time upstart loses track of a running service entirely! That's a deal-breaker. This is as bad as the expect fork failure situation. Is Debian going to make it a policy to forbid all pre-stop scripts in Upstart job files to paper over this problem as well?
https://bugs.launchpad.net/upstart/+bug/539175
Scott makes a terse comment about needing to re-think the start/stop scripts and the event model.

bug report on event unblocking race condition
https://bugs.launchpad.net/upstart/+bug/516713
Scott, makes a terse comment with a sketch as to a solution to keep the events blocked, but clearly its never integrated.

bug report indicating upstart fails to unmount systems cleanly:
https://bugs.launchpad.net/ubuntu/+source/upstart/+bug/10...
read more on this specific issue and how systemd handles this from Lennart's G+ account recently.

bug report indicating failure of expect fork.
https://bugs.launchpad.net/ubuntu/+source/upstart/+bug/53...
and
https://bugs.launchpad.net/upstart/+bug/406397
Scott, as maintainer at the time, writes in a comments to both bugs about a pending rewrite to fix this. His proposed solution, to remove ptrace and to potentially use cgroups instead. He also speaks out against the introduction of pid file tracking as a fallback mechanism for job files to use as an alternative to expect fork pid tracking mechanism. Expect fork is still broken, upstart still does not allow pid tracking as a fallback.

So lets recap. the event handling is racey. The pre-stop scripts design is broken. The event conditional logic is broken, the start/stop command logic is racy/broken, the expect command is broken. What's left. Oh yeah... upstart's backwards compatibility for existing sysvinit scripts is good enough to rely on. But if you want to rely on anything upstart purports to bring to the table..get ready for dentist visit like fun time.

A call for votes in the Debian init system discussion

Posted Jan 27, 2014 6:46 UTC (Mon) by nirbheek (subscriber, #54111) [Link]

Awesome. Thanks for the detailed list, jspaleta!

A call for votes in the Debian init system discussion

Posted Jan 27, 2014 10:19 UTC (Mon) by misc (subscriber, #73730) [Link]

It is also worth to note that the latest cgroup integration proposal in upstart ( https://lists.ubuntu.com/archives/upstart-devel/2013-Nove... ) explicitely exclude cgroup to track processes.

I have also been pointed on this post, explaining that the portability of sysvinit is not really what people think it to be ( https://teythoon.cryptobitch.de/posts/on-portability-of-i... )

A call for votes in the Debian init system discussion

Posted Jan 27, 2014 11:07 UTC (Mon) by Cyberax (✭ supporter ✭, #52523) [Link]

Yup. Upstart's motto is: "We do things as differently as possible compared to systemd". Even if it makes new features next to useless - just look at socket activation.

A call for votes in the Debian init system discussion

Posted Jan 28, 2014 8:36 UTC (Tue) by geertj (subscriber, #4116) [Link]

Thanks! The most factual and therefore convincing argument so far in this discussion.


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