Thanks Shawn. Yes I did index some docs after moving to 6.4.0. The release notes did not mention anything about format being changed so I thought it would be backward compatible. Yeah my only recourse is to re-index data. Apart from that it was weird problems overall with 6.4.0. I was excited about using the unified highlighter but the zookeeper flakiness and constant disconnections of solr and sometimes not electing a leader for some collections made me rollback.
Anyway thanks for promptly responding, will be more careful form next time. Thanks Ravi Kiran Bhaskar On Thu, Feb 2, 2017 at 9:41 AM, Shawn Heisey <apa...@elyograg.org> wrote: > On 2/2/2017 7:23 AM, Ravi Solr wrote: > > When i try to rollback from 6.4.0 to my original version of 6.0.1 it now > > throws another issue. Now I cant go to 6.4.0 nor can I roll back to 6.0.1 > > > > Could not load codec 'Lucene62'. Did you forget to add > > lucene-backward-codecs.jar? > > at org.apache.lucene.index.SegmentInfos.readCodec( > SegmentInfos.java:429) > > at > > org.apache.lucene.index.SegmentInfos.readCommit(SegmentInfos.java:349) > > at > > org.apache.lucene.index.SegmentInfos.readCommit(SegmentInfos.java:284) > > > > Hope this doesnt cost me dearly. Any ideas at least on how to rollback > > safely. > > This sounds like you did some indexing after the upgrade, or possibly > some index optimizing, so the parts of the index that were written (or > merged) by the newer version are now in a format that the older version > cannot use. Perhaps the merge policy was changed, causing Solr to do > some automatic merges once it started up. I am not aware of anything in > Solr that would write new segments without indexing input or a merge > policy change. > > As far as I know, there is no straightforward way to go backwards with > the index format. If you want to downgrade and don't have a backup of > your indexes from before the upgrade, you'll probably need to wipe the > index directory and completely reindex. > > Solr will always use the newest default index format for new segments > when you upgrade. Contrary to many user expectations, setting > luceneMatchVersion will *NOT* affect the index format, only the behavior > of components that do field analysis. > > Downgrading the index format would involve writing a custom Lucene > program that changes the active index format to the older version, then > runs a forceMerge on the index. It would be completely separate from > Solr, and definitely not straightforward. > > Thanks, > Shawn > >
