ShardUnavailable
class ShardUnavailable(val collection: String? = null, serverMessage: String? = null) : KdrantException
The request needed a shard whose replicas are not available at the consistency it asked for.
Distinct from ServiceUnavailable, which is the whole node saying "not now", and from CollectionNotFound, which is the collection not existing. Here the collection exists and part of it is unreachable, so the answer would be incomplete rather than absent — which is why Qdrant refuses instead of returning a partial result, and why lowering the read consistency can make the same request succeed.