Jyri Virkki wrote: (snip...) > > Note that there are two aspects here. One is whether to merely allow > coexistence the other is whether to actively support multiple versions. > > In sfw source tree today there is only one apache2 > http://src.opensolaris.org/source/xref/sfw/usr/src/cmd/apache2/ > which today contains 2.2.3 bits and this project plans to update to 2.2.4 > (maybe 2.2.5 if it is out in time, and so on). > > Assuming multiple install locations, when 2.4 comes out it is possible to: > > 1) 2.4.x eventually replaces 2.2.n in the source tree [if > incompatible, only at a minor release point] and a future os releases > include only that 2.4.x; users who upgrade see their 2.2.x install > preserved (not overwritten). No further 2.2.x updates are delivered > but existing installs are not clobbered. > > 2) 2.4.x enters the source tree in a different location and both 2.4.x > and 2.2.n continue to be actively maintained, built and delivered as well. > This doubles all engineering & support costs but provides more options > for users. > > Whether to take on those costs is a business decision of the > distribution. Fortunately we here don't necessarily need to know the > answer yet; if the layout supports it, it can be decided later. >
Agreed. > (OTOH the cost of the extra complexity can't be ignored either. If no > distribution decides to actively maintain multiple version > concurrently, the extra file layout complexity is just clutter > complicating both build environments as well as usage (more complex > paths, multiple config sets, potential unintended interactions between > mismatched libs, etc). No free lunch.) > > > While this is the apache2 case, it's worth pointint out that the php > case went with a versioned layout, /usr/php5/[version]/... > ... but not without a significant amount of discussion and a near derailment because there wasn't a good understanding of what the real rules should be... which is why I thought it was worth pointing to it. I suspect there are things I don't know about though, since it wasn't all hashed out on that list. That, and I felt it needed to be said that in previous discussion on sfwnv-discuss, with some projects, it was pointed out that we may not know (in part because we haven't asked) how/when they change compatibility across releases or even patches, so the versioned layout may require x.y or x.y.z or even x.y.z-a. - Matt -- Matt Ingenthron - Web Infrastructure Solutions Architect Sun Microsystems, Inc. - Global Systems Practice http://blogs.sun.com/mingenthron/ email: matt.ingenthron at sun.com Phone: 310-242-6439
