ELS 1.7 hotspot issues with shard allocation

We are using ELS 1.7 version primarily with gray log to for our logging datastore with multiple indexes.

We have 6 node cluster with all nodes as data + master.
We are seeing issues when one of them node goes down and we bring another node in the cluster then new node gets most of the shards and that node becomes hot spot.

Any help will be greatly appreciated.


Any help on this please