I am currently working on a tool to identify (and in some cases fix) the
incompatibilities in the Solr configuration (e.g. schema.xml,
solrconfig.xml etc.) between major versions of Solr.
My goal is to simplify the Solr upgrade process by providing upgrade
instructions tailored to your configuration. These instuctions can help you
to answer following questions
- Does my Solr configuration have any backwards incompatible sections? If
yes which ones?
- For each of the incompatibility - what do I need to do to fix this
incompatibility? Where can I get more information about why this
incompatibility was introduced (e.g. references to Lucene/Solr jira)?
- Are there any changes in Lucene/Solr which would require me to do a full
reindexing OR can I get away with an index upgrade?
The initial prototype of this tool is available @
For comments (or suggestions) please refer to
I have implemented upgrade rules for Solr 4 -> Solr 5 and Solr 5 -> Solr 6
by referring to upgrade instructions in the Solr release notes. But during
testing I found that many of the configuration changes (e.g. plugin
deprecations) are not listed in the upgrade section. I am working on
identifying such configuration changes and adding upgrade rules
accordingly. I would love any community participation in improving this
I will be presenting a talk titled "Apache Solr - Upgrading your upgrade
experience" @ Lucene revolution this year. Please do attend to know more
about simplifying Solr upgrade process.