On 3/24/2016 9:45 AM, Jack Krupansky wrote: > Does anybody know if we have doc on the recommended process for upgrading > data after upgrading Solr? Sure the upgraded version will work fine with > that old data, but unless the data is upgraded, the user can't then upgrade > to the next major release after that. This is a case in point - the user is > on 4.x and upgrades to 5.x with that 4.x data, but will want to upgrade to > 6.x shortly, but that will require the 4.x data to be rewritten > (force-merged?) to 5.x first.
In response to Bram's earlier message: You are correct. Solr (Lucene, actually) only maintains compatibility with indexes from the previous major version, so 6.x will read 5.x indexes, but not indexes built by 4.x or earlier. Back to this message: Running an optimize (force merge) should convert the index to the new format. There is also an offline index converter that I've never used, which is probably the preferred method. I take a slightly different approach -- when I upgrade (from *any* version), I delete all the data directories, let Solr recreate them on restart, and rebuild the indexes from the original data source. I do this to avoid *any* potential problems related to upgrading. Thanks, Shawn
