No, you cannot just use the collection name. Replicas are just cores. You can host many replicas of a single collection on a single Solr node in a single CoreContainer (there’s only one per Solr JVM). If you just specified a collection name how would the code have any clue which of the possibilities to return?
The name is in the form collection_shard1_replica_n21 How do you know where the doc you’re working on? Put the ID through the hashing mechanism. This isn’t the same at all if you’re running stand-alone, then there’s only one name. But as I indicated above, your ask for just using the collection name isn’t going to work by definition. So perhaps this is an XY problem. You’re asking about getCore, which is a very specific, low-level concept. What are you trying to do at a higher level? Why do you think you need to get a core? What do you want to _do_ with the doc that you need the core it resides in? Best, Erick > On Aug 28, 2019, at 5:28 PM, Arnold Bronley <arnoldbron...@gmail.com> wrote: > > Wait, would I need to use core name like collection1_shard1_replica_n4 > etc/? Can't I use collection name? What if I have multiple shards, how > would I know where does the document that I am working with lives in > currently. > I would rather prefer to use collection name and expect the core > information to be abstracted out that way. > > On Wed, Aug 28, 2019 at 5:13 PM Erick Erickson <erickerick...@gmail.com> > wrote: > >> Hmmm, should work. What is your core_name? There’s strings like >> collection1_shard1_replica_n4 and core_node6. Are you sure you’re using the >> right one? >> >>> On Aug 28, 2019, at 3:56 PM, Arnold Bronley <arnoldbron...@gmail.com> >> wrote: >>> >>> Hi, >>> >>> In a custom Solr plugin code, >>> req.getCore().getCoreContainer().getCore(core_name) is returning null >> even >>> if core by name core_name is loaded and up in Solr. req is object >>> of SolrQueryRequest class. I am using Solr 8.2.0 in SolrCloud mode. >>> >>> Any ideas on why this might be the case? >> >>