Let's say we have a requirement where we would like to place:
e.g. exact 1 replica on either of the respective 3 solr nodes, solr-node-1, solr-node-2, solr-node-3, and rest of the replicas can be placed on corresponding solr nodes.
Right now we don't have a straightforward manner of doing the same. Autoscaling cluster policy also doesn't support such behavior, but instead takes an array of solr node names and treat them as separate rules as per https://lucene.apache.org/solr/guide/7_7/solrcloud-autoscaling-policy-preferences.html#sysprop-attribute.