|Rajini Sivaram||Jun 11, 2008 6:22 am|
|Graham Charters||Jun 12, 2008 1:07 am|
|Rajini Sivaram||Jun 12, 2008 2:50 am|
|Simon Nash||Jun 12, 2008 4:05 am|
|Rajini Sivaram||Jun 12, 2008 6:29 am|
|Graham Charters||Jun 13, 2008 8:14 am|
|Mike Edwards||Jun 13, 2008 2:21 pm|
|Mike Edwards||Jun 13, 2008 2:30 pm|
|Mike Edwards||Jun 13, 2008 2:43 pm|
|Jean-Sebastien Delfino||Jun 13, 2008 3:12 pm|
|Rajini Sivaram||Jun 16, 2008 8:05 am|
|ant elder||Jul 4, 2008 8:35 am|
|Rajini Sivaram||Jul 7, 2008 2:00 am|
|Subject:||Versioning of Tuscany|
|From:||Rajini Sivaram (raji...@googlemail.com)|
|Date:||Jun 11, 2008 6:22:33 am|
Following on from the discussion on OSGi-enabling third party libraries ( http://markmail.org/message/snltdk2yovr6maq5), this thread addresses the options for versioning Tuscany bundles and 3rd party libraries distributed with Tuscany and the implications of choosing these options. I have put together some notes on the wiki ( http://cwiki.apache.org/confluence/display/TUSCANYWIKI/Tuscany+Versioning)
There were two outstanding questions from Simon Nash in the previous discussion which I will summarize here to ensure that they are not lost in this discussion.
1. Why can't we generate import constraints which will suit all applications? 2. *I'm concerned by the assumption here that Tuscany's versions of 3rd party bundles will be used both by Tuscany and by applications. An application may be using other software as well as Tuscany, and this other software may include its own versions of bundles for javax.servlet or jaxb. If Tuscany requires its versions of these bundles to be used, and the other software requires its versions to be used, this requires the application developer to understand how to resolve any conflicts.*
The answer to 1) relates to how broad (or narrow) version ranges in imports are. Broad ranges prevent isolation and reduce scope for side-by-side execution, narrow ranges prevent class sharing and upgrading to newer versions. There is more detail with examples on the wiki.
Question 2) is addressed first on the wiki (Figure 1 and Figure 2 show these scenarios). I would personally like to follow OSGi best practice and enable maximum sharing. There are some cases where we have no choice but to share (eg. SDO). I don't believe we can eliminate conflicts altogether - but following standard practice will make it less complicated for OSGi developers to resolve conflicts.