I was testing PRS collection creation with larger collections today (previously I had tested with many small collections) and it seemed to be having trouble keeping up.
I was running a 4 node instance, each JVM with 4G Heap in k8s, and a single zookeeper.
With this cluster configuration, I am able to create several (at least 10) collections with 11 shards and 11 replicas using the "old way" of keeping state. These collections are created serially, waiting for all replicas to be active before proceeding.
However, when attempting to do the same with PRS, the creation stalls on collection 2 or 3, with several replicas stuck in a "down" state. Further, when attempting to delete these collections using the regular API it sometimes takes several attempts after getting stuck a few times as well.