David, do you
expect
/mlt-collection,mlt-collection-2/select?q={!mlt+qf%3Dlowerfilt_u+mindf%3D0+mintf%3D1}100
works with no code changes? It doesn't. We need to choose which part to
fix: rtg or mltQP.
GET
http://127.0.0.1:38145/solr/mlt-collection,mlt-collection-2/select?q=%7B%21mlt+qf%3Dlowerfilt_u+mindf%3D0+mintf%3D1%7D100&wt=javabin
HTTP/1.1
482098 ERROR (qtp739992701-56-null-10) [n:127.0.0.1:38145_solr
c:mlt-collection s:shard2 r:core_node3 x:mlt-collection_shard2_replica_n1
t:null-10] o.a.s.h.RequestHandlerBase Client exception
org.apache.solr.common.SolrException: Error completing MLT request. Could
not fetch document with id [100]
at org.apache.solr.search.mlt.CloudMLTQParser.parse(CloudMLTQParser.java:54)
at org.apache.solr.search.QParser.getQuery(QParser.java:196)
at
org.apache.solr.handler.component.QueryComponent.prepare(QueryComponent.java:190)
[x] Traditional sentence regarding wasteful query parsing on
coordinator node.
On Thu, May 7, 2026 at 3:47 PM David Smiley <[email protected]> wrote:
> We've discussed in the dev list recently a strong distaste for the
> "collection" param. Is the issue you speak of equivalent if the collection
> is instead in the natural place in the path is comma-delimited?
>
> On Thu, May 7, 2026 at 3:33 AM Mikhail Khludnev <[email protected]> wrote:
>
> > Devs,
> > After looking into it, I've got a two chairs question, either:
> >
> > - manage RTG /get to handle `collection`
> > <
> >
> https://github.com/apache/solr/blob/main/solr/core/src/java/org/apache/solr/handler/component/RealTimeGetComponent.java#L1046
> > >
> > param,
> > or
> > - let {!mlt} ignore no doc found error
> > <
> >
> https://github.com/apache/solr/blob/a2370b58380e61633e0e1b65312bb33201eea3cd/solr/core/src/java/org/apache/solr/search/mlt/CloudMLTQParser.java#L53
> > >
> > in case if the `collection` param is sent, assuming the will be found
> in
> > another collection
> >
> > The latter approach causes a slight negative regression: it won't throw
> an
> > error in case of the nonexistent ID anymore.
> > So, which one do you choose?
> > .
> >
> > On Wed, May 6, 2026 at 8:49 PM Mikhail Khludnev <[email protected]> wrote:
> >
> > > Hi there.
> > > Here we got https://github.com/mkhludnev/solr/pull/1 it's a rough cut.
> > > How you feel about it?
> > >
> > > On Wed, May 6, 2026 at 8:06 PM Mikhail Khludnev <[email protected]>
> wrote:
> > >
> > >> Hi
> > >> It looks like
> > >>
> >
> https://github.com/apache/solr/blob/main/solr/core/src/java/org/apache/solr/search/mlt/CloudMLTQParser.java#L101
> > >> is not clusteraware at all.
> > >> It lacks functionality, needs to be developed.
> > >>
> > >> On Wed, May 6, 2026 at 7:47 PM Till Kinstler <[email protected]> wrote:
> > >>
> > >>> Hi all,
> > >>>
> > >>> we have a use case, where we would like to make a MoreLikeThis Query
> > >>> Parser request across two collections (of multiple shards each) in a
> > >>> SolrCloud. The two collections share the same index schema.
> > >>> The request looks like
> > >>> q={!mlt qf=field1,field2}ID&collection=collection1,collection2
> > >>>
> > >>> It results in an error message "Error completing MLT request. Could
> not
> > >>> fetch document with id [ID]" from one of the shards of the collection
> > >>> not containing the document with id ID.
> > >>>
> > >>> So I guess, while the MoreLikeThis Query Parser is "SolrCloud aware"
> > and
> > >>> can handle MLT requests across multiple shards of one collection
> (works
> > >>> fpr us), it can not deal with multiple collections? Or are we missing
> > >>> something? Is there a way to send one MoreLikeThis Query Parser
> request
> > >>> to multiple SolrCloud collections?
> > >>>
> > >>> Thanks for any help,
> > >>> Till
> > >>>
> > >>> --
> > >>> Till Kinstler
> > >>> Verbundzentrale des Gemeinsamen Bibliotheksverbundes (VZG)
> > >>> Platz der Göttinger Sieben 1, D 37073 Göttingen
> > >>> [email protected], http://www.gbv.de/
> > >>>
> > >>>
> > >>
> > >> --
> > >> Sincerely yours
> > >> Mikhail Khludnev
> > >>
> > >
> > >
> > > --
> > > Sincerely yours
> > > Mikhail Khludnev
> > >
> >
> >
> > --
> > Sincerely yours
> > Mikhail Khludnev
> >
>
--
Sincerely yours
Mikhail Khludnev
