A test that I wrote in
SOLR-11066 found the following problem:
Cluster: 2 nodes
Collection: 1 shard, 3 replicas, maxShardsPerNode=5
No autoscaling policy or preference applied
When the trigger runs, the computed plan needlessly shuffles all three replicas and then proceeds to return suggestions with only numbers as core names. These cores do not exist. I found that these numbers are generated internally by the framework as placeholders for moved cores for further calculations. They should never ever be suggested to the users.