We do group queries with Solrcloud all the time. You must set up your collection so that all values for the field you are grouping on are in the same shard. This can easily be done with the composite router. Basically you do this be creating a unique field that contains the field to group on, with your unique id: <groupfield>!<uniqueid>
See https://lucene.apache.org/solr/guide/6_6/shards-and-indexing-data-in-solrcloud.html#ShardsandIndexingDatainSolrCloud-DocumentRouting for more details. Solrcloud does limit you to grouping on fields, you cannot group on function queries On Fri, May 4, 2018 at 6:37 AM, Diego Ceccarelli (BLOOMBERG/ LONDON) < dceccarel...@bloomberg.net> wrote: > Hello, > > I'm not sure 100% but I think that if you have multiple shards the number > of docs matched in each group is *not* guarantee to be exact. Increasing > the rows will increase the amount of partial information that each shard > sends to the federator and make the number more precise. > > For exact counts you might need one shard OR to make sure that all the > documents in the same group are in the same shard by using document routing > via composite keys [1]. > > Thinking about that, it should be possible to fix grouping to compute the > exact numbers on request... > > cheers, > Diego > > > [1] https://lucene.apache.org/solr/guide/6_6/shards-and- > indexing-data-in-solrcloud.html#shards-and-indexing-data-in-solrcloud > > > From: solr-user@lucene.apache.org At: 05/04/18 07:53:41To: > solr-user@lucene.apache.org > Subject: the number of docs in each group depends on rows > > Hi, > We used Solr Cloud 7.1.0(3 nodes, 3 shards with 2 replicas). When we used > group query, we found that the number of docs in each group depends on the > rows number(group number). > > difference: > <http://lucene.472066.n3.nabble.com/file/t494000/difference.jpeg> > > when the rows bigger then 5, the return docs are correct and stable, for > the > rest, the number of docs is smaller than the actual result. > > Could you please explain why and give me some suggestion about how to > decide > the rows number? > > > -- > Sent from: http://lucene.472066.n3.nabble.com/Solr-User-f472068.html > > > -- This message and any attachment are confidential and may be privileged or otherwise protected from disclosure. If you are not the intended recipient, you must not copy this message or attachment or disclose the contents to any other person. If you have received this transmission in error, please notify the sender immediately and delete the message and any attachment from your system. Merck KGaA, Darmstadt, Germany and any of its subsidiaries do not accept liability for any omissions or errors in this message which may arise as a result of E-Mail-transmission or for damages resulting from any unauthorized changes of the content of this message and any attachment thereto. Merck KGaA, Darmstadt, Germany and any of its subsidiaries do not guarantee that this message is free of viruses and does not accept liability for any damages caused by any virus transmitted therewith. Click http://www.emdgroup.com/disclaimer <http://www.emdgroup.com/disclaimer> to access the German, French, Spanish and Portuguese versions of this disclaimer.
