IIUC the 5x->7x upgrade won't immediately fail like a 6x->8x upgrade
would, but neither is it really expected to produce the results you
expect due to differences in the index formats.
On Sat, Oct 6, 2018 at 1:31 PM Jan Høydahl <jan....@cominvent.com> wrote:
>
> Shawn, my impression is that you WILL be able to upgrade a 5.x index to 6.x
> and then to 7.x for use with 7.x. So your wiki page is a bit too strict here.
> But if you ever want to upgrade to 8.x, that version will require the "first
> created" version to be 7.0 or later, so you'll need a full reindex.
> See SOLR-12281 <https://issues.apache.org/jira/browse/SOLR-12281>.
>
> I'd also recommend to plan for a full re-index, and also upgrade to new field
> types etc at the same time.
> Feel free to give this tool
> https://github.com/cominvent/solr-tools/tree/master/upgradeindex
> <https://github.com/cominvent/solr-tools/tree/master/upgradeindex> a spin in
> your test environtment and then just test whether 7.5 works on that index :)
>
> --
> Jan Høydahl, search solution architect
> Cominvent AS - www.cominvent.com
>
> > 5. okt. 2018 kl. 16:49 skrev Shawn Heisey <apa...@elyograg.org>:
> >
> > On 10/5/2018 4:41 AM, padmanabhan1616 wrote:
> >> 1. We cannot upgrade directly from 5.x to 7.x instead upgrade to 5.5 then
> >> upgrade to 7 as there is major index format level changes taken place in
> >> 5.5
> >> or later version.
> >
> > Solr 7.x cannot read indexes from 5.5. It can only read indexes that were
> > *fully* constructed by versions back to 6.0.0.
> >
> >> 1. Use index upgrade tool which can allow to upgrade all old indexes to new
> >> index format then we can upgrade to 7.x version easily.
> >
> > We have been advised by Lucene experts that if a version that's at least
> > two major versions before the target version has *EVER* touched the index,
> > there's no guarantee that the index will work even after upgrading through
> > the major versions one by one. The compatibility guarantee only goes back
> > one major version.
> >
> > I would strongly recommend with ANY upgrade that you always build the index
> > from scratch. That produces the best results.
> >
> > This is becoming a frequently asked question, so I have built a wiki page
> > to answer it:
> >
> > https://wiki.apache.org/solr/VersionCompatibility
> >
> > Thanks,
> > Shawn
> >
>
