Then it sounds like that "re-index all the sources in 6.x" is the most feasible 
way, :(. 

-----Original Message-----
From: Trejkaz [mailto:trej...@trypticon.org] 
Sent: Tuesday, August 09, 2016 10:32 AM
To: Lucene Users Mailing List
Subject: Re: Any compatiblity issue in the upgrade from Lucene Core 3.2.0 to 
Core 6.1.0?

On Mon, Aug 8, 2016 at 1:37 PM, Erick Erickson <erickerick...@gmail.com> wrote:
> Yes. Lucene only guarantees back-compatibility with indexes for one 
> major version. That is, a 4.x release can read a 3.x Lucene index. But 
> a 5.x will not read a 3.x.
>
> So you have some options here:
> 1> re-index all your source in 6.x. This is probably easiest....
> 2> upgrade in stages, check out the IndexUpgradeTool.
> Here's the doc for 4.x, which should the 3.x version.
>
> I'll leave it to the people who know Lucene better than me to opine 
> about whether running the IndexUpgrader several times in succession 
> works well.

One problem is that IndexUpgrader and the rest of Lucene has the same package 
name in all the subsequent versions. So there is a fiddly bit of renaming the 
packages in order to get it all into one classpath.
Actually figuring out how to call the upgrader each time was also a bit 
interesting, given that by renaming the packages, the Directory class had to be 
adapted in interesting ways to eventually call through to the current Lucene's 
version of the Directory class. I think the InfoStream had some interesting 
adapting challenges as well.

But even then... I'm not sure IndexUpgrader is 100% flawless. We had one issue 
initially where it wasn't upgrading empty indexes at all, which I think is 
fixed now. More recently I think we have hit a case where a failure occurred 
due to the index being corrupt, but the upgrade method returned as if it was 
completely successful... almost like it was doing the merges in the background, 
but not waiting until they complete.

TX

---------------------------------------------------------------------
To unsubscribe, e-mail: java-user-unsubscr...@lucene.apache.org
For additional commands, e-mail: java-user-h...@lucene.apache.org


---------------------------------------------------------------------
To unsubscribe, e-mail: java-user-unsubscr...@lucene.apache.org
For additional commands, e-mail: java-user-h...@lucene.apache.org

Reply via email to