Maybe try the addIndexes method that takes CodecReader[] instead? It will be somewhat slower, since it fully reads and writes the index, but it should work across major versions?
Mike McCandless http://blog.mikemccandless.com On Thu, Nov 9, 2017 at 3:59 PM, Krishnamurthy, Kannan < kannan.krishnamur...@cengage.com> wrote: > Greetings. > > > We are currently using Lucene 6.1.0, our typical index size is ~ 200GB and > we are planning to move to Lucene 7.0.0. > > > Our daily indexing workflow currently uses IndexWriter.addIndexes() to add > an index(this will be on Lucene 7.0.0) to a copy of the of the 200GB index. > Further it calls IndexWriter.forceMerge(1) to create a single segment. The > addIndexes() now doesn't support different versions of index. > > We are facing an issue in upgrading to Lucene 7.0.0 due to this > limitation. We couldn't afford to do full reindex as there about 50 > different indexes ~ 200GB each. > > > We tried using the LuceneUpgrade tool to upgrade our index to latest > version, however the IndexCreatedVersionMajor is still LUCENE_6_1_0.major, > This is preventing us calling IndexWriter.addIndexes() post upgrade. > > > I am wondering what are our options to upgrade without doing a full > reindex and to continue to use IndexWriter.addIndexes() post upgrade. > > The code snippet below shows the different api calls we make. > > > > @Test > public void addIndexWith7SegmentToDirectoryOnUpgradedSegment() throws > IOException { > IndexUpgrader upgrader = new IndexUpgrader(lucene610Dir); // lucene 6.1.0 > directory 200 GB > upgrader.upgrade(); > > IndexWriter w = new IndexWriter(lucene610Dir, newIndexWriterConfig()); > exception.expect(IllegalArgumentException.class); > exception.expectMessage( > CoreMatchers.containsString("Cannot use addIndexes(Directory) with > indexes that have been created by a different Lucene version")); > w.addIndexes(lucene700Dir); // lucene 7.0.0 daily index > w.forceMerge(1); > w.close(); > } > > Let me know if you need more details. > > > Many thanks > > Kannan. > >
