What's the benefit of splitting nodes instead of large instance with more shards?

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1

Please correct me if I am wrong,

When create domain, if I decide to create 3 instances, data will be split into three nodes. I am just wondering what would be the exact benefit of having more nodes instead of one big instance. We can have more shards so performance should not be an issue. And we will have a replica so server down issue will be okay right?

2

You will have at the end less shards per node which means fewer operations to run on a single node, less memory used...
Less pressure on a single node.

3

Thank you for your answer.