Yes, current Solr comes with a schemaless mode, which can cause errors in some
cases. It must be configured to use classic schema mode, then you provide it
with the schema.xml file you can find in Nutch' conf directory.
> From:Tom Chiverton <t...@extravision.com>
> Sent: Friday 14th October 2016 16:58
> To: firstname.lastname@example.org
> Subject: Re: Nutch 2, Solr 5 - solrdedup causes ClassCastException:
> I don't understand what you mean here. I am not a Solr expert, though
> I've used it a bit in the past, though not with Nutch.
> Is there a schema I should be feeding it ?
> On 14/10/16 15:50, Markus Jelsma wrote:
> > Solr supports schemaless mode, which may be your case. Perhaps it made your
> > digest field multi valued. I'd suggest to use Solr's classic schema
> > factory, and a fixed schema.