On 12/8/2017 1:03 PM, Erick Erickson wrote:
Second, grouping works fine in distributed mode with a couple of
restrictions, see the reference guide. Collapse/Expand (an alternative
to standard grouping) requires that all the members of a group be on
the same shard.
In 5.x, distributed grouping seems to require docValues, while in 4.x it
didn't. I filed an issue about it. Yonik said that this is additional
fallout from LUCENE-5666. I haven't tried it on 6.x or 7.x.
https://issues.apache.org/jira/browse/SOLR-8088
If I send a request to one core, the grouping works, but if I make it
distributed and the field doesn't have docValues, I get an exception.
In order to accommodate the data-mining grouping queries I needed on my
dev server (all production is still running 4.x versions), I used
copyField to a string type with docValues and reindexed.
I am not running SolrCloud for these indexes.
Thanks,
Shawn
