i have 8 data node elk and metricbeat configured with shard 2 replica 1. most of the times all of the shard is maximum spread in 3 node . in order to max performance i trying to create index with 5 shard replica 1 and doing a reindex . but i see all primary , replica created in just 3 nodes instead of using all nodes . 1st node has 4 shard , 2nd node 5 and 3rd node 1.
question is how can i ensure all my primary to be in different node so that my performance is better?
out of 8 nodes 4 nodes have disk size 50% of remaining nodes . i.e 4 nodes have 1.5 tb and others have 3tb . is there problem on performance and unequal allocation