Error when creating partition index with num_replica and node list

create index name on default(name) partition by hash(meta().id) with

{"nodes":["127.0.0.1:9002", "127.0.0.1:9003", "127.0.0.1:9001"], "num_replica":1}

[
{
"code": 5000,
"msg": "GSI CreateIndex() - cause: Fails to create index. Parameter num_replica should be one less than parameter nodes.",
"query_from_user": "create index name on default(name) partition by hash(meta().id) with

{\"nodes\":[\"127.0.0.1:9002\", \"127.0.0.1:9003\", \"127.0.0.1:9001\"], \"num_replica\":1}

"
}
]