Hi, You have to first "convert" your indexes with version 3.x to migrate from 2.x to 4.0. This can be done with the new tool called "IndexUpgrader" (available since Lucene 3.2 or like that). You can call it from command line, it will upgrade all index segments to the latest version you are using to call this tool. You might want to ship your product with a Lucene 3.6.x lucene-core.jar file just to call the IndexUpgrader tool.
If you are starting development, I would now use Lucene 4.0-ALPHA. The final version will come out when you finish your product. As the API changed completely (2 times 2.x->3.x, 3.x->4.0) it's better to not do the work two times. Uwe ----- Uwe Schindler H.-H.-Meier-Allee 63, D-28213 Bremen http://www.thetaphi.de eMail: u...@thetaphi.de > -----Original Message----- > From: Nilesh Vijaywargiay [mailto:nilesh.vi...@gmail.com] > Sent: Tuesday, July 17, 2012 11:14 PM > To: java-user@lucene.apache.org > Subject: Lucene 2.x to 4.x upgrade possible? > > Hi Folks, > > I need your help in determining whether we upgrade to 3.6 or wait till 4.0 > becomes stable. > > We are currently using 2.x version of lucene and would like to upgrade to > 3.6(and 4.0 ultimately). But we were informed by few blogs that 4.0 will not be > backward compatible which means that the our customers who currently have > 2.x will not be able to upgrade to our latest release which would have 4.0. > > Another blog mentioned that people using 2.x and looking upgrade to 4.0 > should wait till 4.0 becomes stable. We are kind of confused with contracting > thoughts here. Does it mean that 4.0 ALPHA doesn't support backward > compatibility and recommendation is to use 4.0 stable for backward > compatiblity? > > Basically, to embark on process of upgrading lucene to 3.6(and 4.0 later) > depends on whether customer having 2.x can upgrade to 4.0 or not. > > Thanks --------------------------------------------------------------------- To unsubscribe, e-mail: java-user-unsubscr...@lucene.apache.org For additional commands, e-mail: java-user-h...@lucene.apache.org