Minor nit. For IndexUpgraderTool and optimize to be identical, you have to
specify maxSegments=1 on optimize.
As of LUCENE-7976, optimize respects the max segment size and does _not_
necessarily rewrite segments that have no deleted documents, especially if
they’re near 5G which is the default
As of Lucene 6, a marker was written into each segment, and when segments are
merged the lowest marker is preserved. If any marker for version of Lucene X-2
is found, you will see the error you see.
This has been a source of considerable confusion. The guarantee of “one major
revision backwards
On 4/1/2019 9:19 AM, Herbert Hackelsberger wrote:
I tried to upgrade my test index from Solr 7.7.1 to Solr 8.0.0.
The file segments_4h7 already contains the string Lucene70.
I upgraded before with this command:
java -cp lucene-core-7.7.1.jar;lucene-backward-codecs-7.7.1.jar
org.apache.lucene.in
