Hello Christopher, Afaik Solr 9 and 8 checks the creation version of the collection/index. Creation version does not change if you empty the collection/index and index again in a newer Solr version. IndexUpgraderTool or changing luceneMatchVersion does not change the creation version either. I checked the binary files when I saw the same issue on Solr 8 and collections/indexes created in Solr4,5 and 6. Solr now supports only collection/index created with Solr-1 versions. Yes,You will need to create a new collection/index in Solr 8 if you plan to use it later on Solr 9.
Hope this helps. Alejandro Arrieta On Thu, Sep 5, 2024 at 5:27 PM Christopher Schultz < ch...@christopherschultz.net> wrote: > All, > > I'm looking at migrating from Solr 7.7.3 to Solr 8.11.3 and I can see > that the new version of Solr has no problem reading the old index files. > > When I look forward to 9.6.1, though, I can see that a quick test of > trying to open an index using the Lucene library that ships with Solr > 9.x reports an error: > > org.apache.lucene.index.IndexFormatTooOldException: Format version is > not supported (resource > BufferedChecksumIndexInput(NIOFSIndexInput(path="/var/solr/data/cschultz_patients/data/index/segments_3t0"))): > > This index was initially created with Lucene 7.x while the current > version is 9.10.0 and Lucene only supports reading the current and > previous major versions. This version of Lucene only supports indexes > created with release 8.0 and later by default. > > While Solr 8 is running, I have deleted all documents in the index and > re-indexed all my documents. After that, repeating the test still gives > that error. > > I can see in solrconfig.xml: > > <luceneMatchVersion>7.3.0</luceneMatchVersion> > > I'm guessing that, after migrating to Solr 8.x I could change this to > Lucene 8.whatever and re-index again, but would that have any effect? > > Will I have to actually delete and re-create the core from scratch in > order to get a Lucene-8-created index? > > -chris >
