RHEL 6: already obsolete ? [LWN.net]

RHEL 6: already obsolete ?

Posted Apr 22, 2010 3:04 UTC (Thu) by lwkejrlej (guest, #64237) [Link]

how do you know they are less buggy?

By the rather long lists of bugs fixed ? Did the RHEL 6 "QA" address all of the bugs present in OO.org 3.1 that are listed as fixed for 3.2 ? Is Red Hat's QA team the same size as OO.org's development team ?

It can be argued that anything with new features carries the risk of bugs. However, recent OO.org, Gnome & KDE are evolutionary releases rather than groundbreaking or totally fresh codebases, and as such it's much more likely that the amount of bugs introduced is less than the number of bugs fixed.

RHEL 6: already obsolete ?

Posted Apr 22, 2010 3:37 UTC (Thu) by rahulsundaram (subscriber, #21946) [Link]

Such assumptions often turn out to be incorrect. Evolutionary releases tend to introduce enough new bugs as well. This is especially the case for desktop environments and large and complex codebases like Openoffice.org. Also importantly, even minor changes in the UI cause alarm from enterprise customers who really don't like change (except for the features they really want but that is another story).

RHEL 6: already obsolete ?

Posted Apr 22, 2010 7:41 UTC (Thu) by evad (subscriber, #60553) [Link]

Of course, this would seem to suggest that you assume that evolutionary releases are introducing more bugs than they fix with each successive release. I'm not sure that this is not the case, otherwise software would simply get worse and worse over time, when I've found that software such as GNOME and (Linux) gets more reliable and stable over time.

The argument is that staying with the old branch and only backporting just the fixes is a good thing. It works whilst the upstream supports it (usually about 6-12 months) but then you are forced to backport fixes to older versions that were never intended to have those fixes. Things break.

Red Hat have admitted this in person to me during subscription negotiations: Red Hat tend to break things badly by back porting critical bug and security patches (as well as new features). They fix security bugs and then they have to fix the fix because it exposed code paths that were never seen upstream.

So, customers should compare the latest stable versions of the software from upstream with an older version being maintained by Red Hat with new features/fixes (cherry picked ones, note!) backported over the top in a way that was never designed.

As you say, newer releases introduce *new* bugs (whilst fixing old ones) and *new* features. I don't really like the Enterprise Linux releases (they are obsolete at release and the package set is small) or the non-enterprise ones (Huge package set but insufficient testing, lots of new untested features, short lifespan). There has to be some middle ground we can get to.

RHEL 6: already obsolete ?

Posted Apr 22, 2010 8:21 UTC (Thu) by rahulsundaram (subscriber, #21946) [Link]

"Of course, this would seem to suggest that you assume that evolutionary releases are introducing more bugs than they fix with each successive release"

That is indeed possible but not what I am suggesting. What I know instead is that even evolutionary updates introduce *new and different* bugs from the previous version while introducing new features and fixing some old bugs. Red Hat cannot simply just use the latest upstream user space for major codebases like a desktop environment or a office suite as has been suggested here. QA, hardware and software certifications take a lot of time and effort.

This is not to claim that backporting is a panacea but it is a solution that has worked better than anything else for the most part for the target market and Red Hat does update leaf packages like Firefox more often and introduce parallel installable versions of new software like Postgres. In the case of Postgres, some customers want the new features in it but simply upgrading to the latest version is not a option when the new version also introduces incompatibilities.

If more upstream projects would stop introducing so many (often avoidable) incompatibilties and take API/ ABI stability more seriously, it would certainly help but I am not sure there is a definitive movement towards that.

RHEL 6: already obsolete ?

Posted Apr 22, 2010 2:37 UTC (Thu) by dag- (subscriber, #30207) [Link]

Also that is good in theory, but in practice new software comes with new features and new unknown bugs, while old software has old known bugs patched.

New releases also ship with new features that change behavior or even interfaces. An Enterprise distribution is supposed to keep behavior and interfaces stable and trusted. So shipping latest software goes against that need that business have. The last thing you want is that a kernel update suddenly impacts performance/behavior and outdo any performance tweaks you prepared and implemented on your 400 servers before.

Of course if you don't have that need, you may as well find yourself using a bleeding edge distribution, or one that is more often updated. But that is not what enterprises desire in general. It's a balance of what you think is important, and that might as well be different for different users.

If a typical hardware lifecycle is about 4 years, and commercial software is adapted to run on a new OS release only after 18 months of general availability, you cannot expect a company to standardize on new OS releases every 6 or 12 months. The preparation and migration of your production environment simply is too time-consuming (and too costly)...

RHEL 6: already obsolete ?

Posted Apr 22, 2010 3:12 UTC (Thu) by lwkejrlej (guest, #64237) [Link]

you cannot expect a company to standardize on new OS releases every 6 or 12 months.

I didn't imply that there should be a major update to a critical component, such as the kernel, every 6 to 12 months. That would be insane.

My point of contention is that there is user-space software available now that fixes bugs present in its earlier versions. Those earlier versions are present in RHEL 6 beta, and I do not see Red Hat's development team being able to backport all of the fixes from the newer version. It's simply easier to take the latest version, before Red Hat pours in the concrete and solidifies everything until 2015 / RHEL 7.

RHEL 6: already obsolete ?

Posted Apr 22, 2010 4:59 UTC (Thu) by airlied (subscriber, #9104) [Link]

But now is when the RHEL6 beta is released. Not composed, *released*. There is a chance my RHEL6 final there will be changes to the package list and version, its also possible there isn't.

Again this isn't a Fedora or Ubuntu, a major amount of stabilisation work has gone into this already. You can't just shove major revisions of apps in the week before beta release. I think you seriously underestimate the amount of work that goes into this prior to the actual beta release. Its not a just a bunch of maintainers chucking shit at a packaging system and hoping it produces a coherent OS. Like I'll guarantee you can say the exact same things about RHEL6 when it finalises, in that there will of course be newer versions of all those components than it ships with, but that isn't what the RHEL OS is aimed at. Its aimed at people who don't care about constant version revisions, they want a stablised version with lots of bug fixes only, not new themes or applets or whatever KDE4.x+1 might drag in along with the bug fixes.

RHEL 6: already obsolete ?

Posted Apr 22, 2010 5:54 UTC (Thu) by lwkejrlej (guest, #64237) [Link]

they want a stablised version with lots of bug fixes only

Fair enough, but can Red Hat guarantee that all the bug fixes present in package version N+1 are backported to version N, which happens to be shipped in RHEL 6 ?

I'm also not totally convinced about the QA process. Going by the embedded versions within the names of package rpms (and the patches in source rpms), it would appear that things such as gnome-panel haven't been really updated from the version in F12. gnome-panel crashes all the time whenever you do a minor interaction with one of its components. This is a highly visible bug that has existed for quite some time, and yet it hasn't been fixed.

RHEL 6: already obsolete ?

Posted Apr 22, 2010 8:26 UTC (Thu) by rahulsundaram (subscriber, #21946) [Link]

"Fair enough, but can Red Hat guarantee that all the bug fixes present in package version N+1 are backported to version N, which happens to be shipped in RHEL 6 ?"

That is never the goal. Just like new features, bug fixes are also cherry picked. Not everything gets the same priority. Upstream projects often exchange one set of known bugs with another set of unknown issues in newer releases. So just moving to a new upstream version doesn't solve the problem.

RHEL 6: already obsolete ?

Posted Apr 23, 2010 14:12 UTC (Fri) by nix (subscriber, #2304) [Link]

On top of that, I've seen code rely on the *presence of bugs* and break if those bugs are fixed. Sure, the code shouldn't rely on those bugs, but often it's nasty closed-source stuff and when you contact the vendor they say 'yes, this is fixed in the next version, please pay $$$$', and because it's closed-source you can't fix it yourself even if you want to.

Sure, for everything other than kernel and daemon bugs you can work around this with suitable library paths, and for kernel and daemon bugs you can work around it with a VM, but if you need a complete virtualized copy of the pre-updated RHEL to get things done, the updates really have done harm, even if all they did was fix bugs.

RHEL is for stability hounds, and often what matters there isn't that there are no bugs but that *the set of bugs does not change*, so the users can consistently work around them.

As a developer, I hate this crusty stuff, but I understand why the users like it.

RHEL 6: already obsolete ?

Posted Apr 24, 2010 19:42 UTC (Sat) by madscientist (subscriber, #16861) [Link]

ITYM "as a user, I hate this crusty stuff, but I understand why the IT folks like it."

:-)

RHEL 6: already obsolete ?

Posted Apr 24, 2010 20:24 UTC (Sat) by nix (subscriber, #2304) [Link]

The users in this case are giant banks. They really do like things to not change much. :)

RHEL 6: already obsolete ?

Posted Apr 25, 2010 1:03 UTC (Sun) by dag- (subscriber, #30207) [Link]

Not just banks, to be honest I prefer my non-technical family members to run something that doesn't require too much attention either as well.

In fact, as long as it is timely and digestible, and there is a clear roadmap for minor updates you've got something you can plan your organization around.