When you say “reindexed”, how exactly was that done? Because if you didn’t start from an empty index, you will have to re-index from scratch to use 8x.
Starting with 6.x, a marker is written whenever a segment is created indicating what version was used. Whenever two or more segments are merged, the earliest marker is preserved. Then, starting with Solr 8x, if any segment has a marker more than one major revision old, Lucene will refuse to open the index. So when you say “reindexed” and all you did was re-index every doc into an existing index, the 6x marker is preserved and you’ll be out of luck. IndexUpgraderTool, BTW, merely does an optimize to one segment, which has it’s own downsides, see: https://lucidworks.com/post/segment-merging-deleted-documents-optimize-may-bad/ and the associated post for 7.5+. It doesn’t (and can’t) make the index look just like the current index, so Lucene won’t try. Paraphrasing Robert Muir, Lucene stores an efficient, derived index rather than the raw data. So what’s in the index is y, where y=f(x). Since x may not be present, Lucene can’t recreate y when major versions change. Best, Erick > On Mar 6, 2020, at 11:08, Webster Homer <webster.ho...@milliporesigma.com> > wrote: > > We are looking at upgrading our Solrcoud instances from 7.2 to the most > recent version of solr 8.4.1 at this time. The last time we upgraded a major > solr release we were able to upgrade the index files to the newer version, > this prevented us from having an outage. Subsequently we've reindexed all our > collections. However the Solr documentation for 8.4.1 states that we need to > be at Solr 7.3 or later to run the index upgrade. > https://lucene.apache.org/solr/guide/8_4/solr-upgrade-notes.html > > So if we upgrade to 7.7, and then move to 8.4.1 and run the index upgrade > script just once? > I guess I'm confused about the 7.2 -> 8.* issue is it data related? > > Regards, > Webster > > > > This message and any attachment are confidential and may be privileged or > otherwise protected from disclosure. If you are not the intended recipient, > you must not copy this message or attachment or disclose the contents to any > other person. If you have received this transmission in error, please notify > the sender immediately and delete the message and any attachment from your > system. Merck KGaA, Darmstadt, Germany and any of its subsidiaries do not > accept liability for any omissions or errors in this message which may arise > as a result of E-Mail-transmission or for damages resulting from any > unauthorized changes of the content of this message and any attachment > thereto. Merck KGaA, Darmstadt, Germany and any of its subsidiaries do not > guarantee that this message is free of viruses and does not accept liability > for any damages caused by any virus transmitted therewith. > > > > Click http://www.merckgroup.com/disclaimer to access the German, French, > Spanish and Portuguese versions of this disclaimer.
