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.
