Also, you can specify custom placement rules, see: https://cwiki.apache.org/confluence/display/solr/Rule-based+Replica+Placement
But Shawn's statement is the nub of what you're seeing, by default multiple JVMs on the same physical machine are considered separate Solr instances. Also note that if you want to, you can specify a nodeSet when you create the nodes, and in particular the special value EMPTY. That'll create a collection with no replicas and you can ADDREPLICA to precisely place each one if you require that level of control. Best, Erick On Mon, May 8, 2017 at 7:44 AM, Shawn Heisey <apa...@elyograg.org> wrote: > On 5/8/2017 5:38 AM, Bernd Fehling wrote: >> boss ------ shard1 ----- server2:7574 >> | |-- server2:8983 (leader) > > The reason that this happened is because you've got two nodes running on > every server. From SolrCloud's perspective, there are ten distinct > nodes, not five. > > SolrCloud doesn't notice the fact that different nodes are running on > the same server(s). If your reaction to hearing this is that it > *should* notice, you're probably right, but in a typical use case, each > server should only be running one Solr instance, so this would never happen. > > There is only one instance where I can think of where I would recommend > running multiple instances per server, and that is when the required > heap size for a single instance would be VERY large. Running two > instances with smaller heaps can yield better performance. > > See this issue: > > https://issues.apache.org/jira/browse/SOLR-6027 > > Thanks, > Shawn >