Elasticsearch Version: 6.5.4

There are 16 nodes in my cluster and the index has 10 shards.

There is a new index created everyday.

It works well for several months.

But a strange thing happen today. 10 shards of the new index are allocated to on node.

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I’m sure all nodes are working well. None node or procession restarting.

How can this happen?


There is a simple solution using index setting index.routing.allocation.total_shards_per_node