tag:blogger.com,1999:blog-5037914952809905483.post3638796932098147767..comments2009-01-04T12:26:53.660-08:00Jason Whaleyhttp://www.blogger.com/profile/05362549195700900828noreply@blogger.comBlogger3125tag:blogger.com,1999:blog-5037914952809905483.post-30047227309586737482009-01-04T12:26:00.000-08:002009-01-04T12:26:00.000-08:00The sort of things you are talking about imply that the operation would, in effect, be that of a collection of separate libraries. I believe that would be a good idea, but problems could come out of it. Some form of versioning for each library would be necessary to prevent chaos.Arthur Griffithhttp://www.blogger.com/profile/06764524924924238800noreply@blogger.comtag:blogger.com,1999:blog-5037914952809905483.post-31498935793040770182009-01-02T17:40:00.000-08:002009-01-02T17:40:00.000-08:00Hi Jason, thanks for the link.<BR/><BR/>I have to point out that these are all <B>potential</B> benefits that I see from modularising the JVM. Depending on the implementation, we may not get some or all of those benefits.<BR/><BR/>You may have noticed from my post that I am a strong supporter of OSGi. My opinion is that Sun should leverage OSGi as much as possible in their effort to modularise the JVM, and doing so would result in the benefits you highlighted. However, previous module systems they have proposed (e.g. JSR 277) have been non-dynamic and also had poor support for properly decoupling modules, so if they go down that route again then you're likely to be disappointed by the result.<BR/><BR/>Incidentally, Apache Harmony successfully used OSGi to modularise its implementation of the core JRE libs, so we know it can be done and there is no real need to invent a new module system.<BR/><BR/>You can use OSGi <B>today</B> to modularise the rest of your server applications, i.e. everything above the level of the JRE. Many server application vendors are already doing this, including pretty much all of the Java EE servers you've ever heard of (WebSphere, WebLogic, JBoss and GlassFish are all using OSGi). Also many ESB/SOA servers (e.g. Mule, ServiceMix, WS02, Project Fuji) are doing this.<BR/><BR/>So, I don't think this is pie-in-the-sky at all. It's starting to happen already.Neil Bartletthttp://www.blogger.com/profile/08588098030811273044noreply@blogger.comtag:blogger.com,1999:blog-5037914952809905483.post-88596944317396780602009-01-02T16:04:00.000-08:002009-01-02T16:04:00.000-08:00This certainly is interesting. I also wonder how this plays with things like OSGI (which is something I'm personally very interested in) and JSR-291 and friends. While things like OSGI don't go as far as eliminating classloaders, et al, it could be seen as a more tenable goal if parts of the standard libraries are bundled this way and offer many of the same benefits in HA scenarios.E. Sammerhttp://www.blogger.com/profile/01099836951897026435noreply@blogger.com