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.index.IndexUpgrader C:\solr\server\solr\syneris\data\index\
Everything went successful, when I start solr via solr.cmd start, no errors are
logged.
Now, when I try to upgrade to Solr 8 I also tried to upgraded the index with
the following command:
java -cp lucene-core-8.0.0.jar;lucene-backward-codecs-8.0.0.jar
org.apache.lucene.index.IndexUpgrader C:\solr\server\solr\syneris\data\index\
Upgrading through two or more major versions is not supported. If the
index has ever been touched by version 6.6.x or older, then 8.x will not
be able to read that index, even if it is upgraded to 7.x first.
Reindexing from scratch is the only option. In my opinion, all indexes
should be rebuilt from scratch when upgrading, even when the new version
can read the old format.
Thanks,
Shawn
