Ability create index when num_replica not satisfied

create index ix3 on default(c9) WITH {"num_replica": 1};

Also Alter.

Index creation for index ix3, bucket default, scope _default, collection _default cannot start. Reason: Fails to create index.  There are not enough indexer nodes to create index with replica count of 1. Some indexer nodes may be marked as excluded.

Instead of error can this change to warning on statement and continue possible replicas and let rebalance satisfy based on nodes (off course Interface need to change include warning) and log the warning.

With 2 index nodes, replica 1 allowed. Now one node taken out rebalanced. HA is not satisfied, but when new node added it satisfies replica. Same way we should do for create/alter index.

Use case:
N1QL UPDATE stats creates its own bucket/collection and primary index internally.
For HA it needs to pass num_replica i.e. it needs to know number of indexer nodes in cluster.
primary index is created when 1 index node. Later new nodes added no HA. User has explicitly to do ALTER.