Thank you Shai for the quick response. Have responded inline.
On Fri, Aug 2, 2013 at 5:37 PM, Shai Erera <ser...@gmail.com> wrote: > Hi > > You cannot just update headers -- the file formats have changed. Therefore > you need to rewrite the index entirely, at least from 2.3.1 to 3.6.2 (for > 4.1 to be able to read it). > Yeah, as of now, we call IndexUpgrader of 3.6.2 and then IndexUpgrader of 4.0, and then the indices become readable by 4.1 > If your index is already optimized, then IndexUpgrader is your best option. > The reason it calls forceMerge(1) is that it needs to guarantee *every* > segment in your index gets rewritten. > Understood. Looks like we will have to stick to what we have written as on date. > > BTW, you might want to upgrade to 4.4 already. > Yeah, we upgraded the code base when 4.1 was the most recent version, now that we are looking forward to migrate the older indices to be compatible. Thanks again. > > Shai > > > On Fri, Aug 2, 2013 at 2:49 PM, Ramprakash Ramamoorthy < > youngestachie...@gmail.com> wrote: > > > Team, > > > > We are migrating from lucene version 2.3.1 to 4.1. We are > migrating > > the indices as well, and we do this in two steps 2.3.1 to 3.6.2 and 3.6.2 > > to 4. We just call IndexUpgrader.upgrade(), using the > > IndexUpgraderMergePolicy. I see that, the upgrade() method actually > calls a > > forcemerge(1) over the indices. > > > > However, we have all our indices optimized and there are no > deletes > > as well. This forcemerge(1) seems a very costly operation and since our > > index is already optimized, there is no space benefit as well. Is there a > > faster way to upgrade our indices (like reading the indices and modifying > > the headers, something of that sort)? We are not expecting any compaction > > during the process. > > > > Currently it takes 4 minutes for a GB of index to get migrated > to > > 4.1 from 2.3.1. Any pointers would be appreciated. Thanks in advance. > > > > > > -- > > With Thanks and Regards, > > Ramprakash Ramamoorthy, > > Chennai, India. > > > -- With Thanks and Regards, Ramprakash Ramamoorthy, Chennai, India.
