It does seem that the Lucene42DocValuesProducer has changed its internal version and that is what its complaining about.
Cheers Shawn, Ok my misunderstanding on the codec stuff then, as I said probably not a common occurrence but good to know. On 7 August 2013 17:32, Shawn Heisey <s...@elyograg.org> wrote: > On 8/7/2013 3:33 AM, Daniel Collins wrote: > >> I had been running a Solr 4.3.0 index, which I upgraded to 4.4.0 (but >> hadn't changed LuceneVersion, so it was still using the LUCENE_43 codec). >> >> I then had to back-out and return to a 4.3 system, and got an error when >> it >> tried to read the index. >> >> Now, it was only a dev system, so not a problem, and normally I would use >> restore a backup anyway, but shouldn't this work? If I haven't changed >> the >> codec, then Solr 4.4 should be using the same code as 4.3, so the data >> should be compatible, no? >> > > Using an index from a newer version is never guaranteed, and usually will > NOT work. The luceneMatchVersion setting doesn't typically affect index > format, it usually affects how analysis and query parser components work - > so you can tell Solr to use buggy behavior from an earlier release. > > Unless you actually change aspects of the codec (postings format, > docvalues format, etc), Solr uses the Lucene codec defaults, which can (and > usually does) change from release to release. > > Looking through the Lucene 4.4 CHANGES.txt file (not the Solr file), > LUCENE-4936 looks like a change to the DocValues format. I can't tell from > the description whether LUCENE-5035 is a format change or a change in how > Lucene handles sorting in memory. The evidence I can find suggests that > the format is still called Lucene42DocValuesFormat, but apparently it > doesn't work the same. > > Thanks, > Shawn > >
