Unassigned shards: NODE_LEFT (Cloud)

Hello guys,

I encountered a few problems with my Elasticsearch cluster (on cloud) and exactly, i have around 25 unassigned shards with the reason NODE_LEFT and one with REPLICA_ADDED (after I tried to add a replica).

I want to solve this problem without having to delete the indices and I looked around for a solution, but I didn't see one for the cloud.

Any suggestions?


NODE_LEFT just says that the shard became unassigned because a node left the cluster. The more interesting question is why the shard is not being assigned again, and for that you should use the cluster allocation explain API.

Hi David and thank you for replying. This is the output from the cluster allocation explain API:
"decider" : "same_shard",
"decision" : "NO",
"explanation" : "a copy of this shard is already allocated to this node [[test_index-000002][0], node[6NlWny21g5SdCMUzGtlcgWaszSQ], [P], s[STARTED], a[id=_AZRb0yaTJWOncpxzpNB0dsy8Q]]"
"decider" : "awareness",
"decision" : "NO",
"explanation" : "there are too many copies of the shard allocated to nodes with attribute [logical_availability_zone], there are [2] total configured shard copies for this shard id and [2] total attribute values, expected the allocated shard count per attribute [2] to be less than or equal to the upper bound of the required number of shards per attribute [1]"

It is pretty intuitive why this happened, but I don't know how to solve it.

That's not the full output. That's just saying we can't allocate a copy of [test_index-000002][0] to this node because there's already a copy there.