Thanks [Christian_Dahlqvist]
We have over 100 micro-services, so each micro-service has its own index. We have default shard number set to 6. Our index size differs from few MBs to 500-660 GB.
Also currently some of our nodes in the cluster have primary shards only. Is there a setting which needs to be tuned so that all primary shards in the cluster are equally distributed on nodes and so are the replicas after that.