Hey there! I have one particularly high throughput logging cluster which processes about 1tb of data per day. Most of that data goes into a single index with 25 shards (which exactly matches the number of nodes in the cluster, intentionally).
I was looking at the cluster today and I noticed that the primary shards aren't actually distributed evenly across nodes in the cluster - some nodes have 2 primary shards, and some nodes have 0. Wouldn't the best configuration for maximum indexing speed be to have one primary shard per node?? There are almost no other relevant indices on that cluster.
Is there a setting I can set to tell elasticsearch not to allow two primary shards from the same index to live on the same node??