On Fri, Aug 2, 2013 at 5:56 PM, Shai Erera <[email protected]> wrote: > Unfortunately you cannot upgrade directly from 2.3.1 to 4.1. > > You can consider upgrading to 3.6.2 and stop there. Lucene 4.1 can read 3.x > indexes, and when segments will are merged, they are upgraded automatically > to the newest file format. > However, if this single segment is too big, such that it won't be picked > for merges, you will need to upgrade it anyway when one day you will > upgrade to Lucene 5.0. > So I'd say, if you're not stressed with time, upgrade to 4.1 now ... it's a > one time process. >
Thank you Shai, doing it right away :) Staying with an older version of lucene for a longer period of time has been a bad idea. > > Shai > > > On Fri, Aug 2, 2013 at 3:22 PM, Ramprakash Ramamoorthy < > [email protected]> wrote: > > > Thank you Shai for the quick response. Have responded inline. > > > > > > On Fri, Aug 2, 2013 at 5:37 PM, Shai Erera <[email protected]> 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 < > > > [email protected]> 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. > > > -- With Thanks and Regards, Ramprakash Ramamoorthy, Chennai, India
