Folks, I'll chip in with one observation here.
If Tuscany itself allows the use of a range of versions of some 3rd party library, then in principle given that we attempt a form of test driven development, we should be testing with ALL of the versions of that 3rd party library.
If we don't do that, then we are really "winging it" in terms of testing - we are implying that the Tuscany code has been verified to work with any and all of the levels within the range, when we have not done that.
Experience in general says that it is not wise to assume that because Tuscany works with level 1.x of some library, that it will also work with level 1.x+1. Loosening a tight range is going to be tough.
Yours, Mike. Rajini Sivaram wrote:
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. Thoughts? Thank you... Regards, Rajini
