I think I've finally gotten a grasp of the fundamental understanding of how to allocate shards for Elasticsearch. Please correct me if I'm wrong, this is what I've pieced together:
- Ideally, there should only exist one shard per index, per node.
- The only reason why we would ever want to configure more than one shard IS to over-allocate for future growth (i.e. adding more nodes to physically support the data).
Now, assuming what I have above is correct, I then wonder if there are any performance issues or differences if I only had one node with 1 shard versus one node with 5 shards. Can anyone enlighten me on this subject?