[Bug]: Unable set nlist while creating IVF_FLAT IP index

[afzalIbnSH]

Is there an existing issue for this?

• I have searched the existing issues

Environment

- Milvus version: zilliz serverless (Compatible With 2.3.x)
- Deployment mode(standalone or cluster): zilliz cloud
- MQ type(rocksmq, pulsar or kafka): zilliz cloud
- SDK version(e.g. pymilvus v2.0.0rc2): 2.4.0
- OS(Ubuntu or CentOS): zilliz cloud
- CPU/Memory: zilliz cloud
- GPU: zilliz cloud
- Others: -

Current Behavior

Below is my code;

    fields = [
        FieldSchema(
            name=Columns.ID.value,
            dtype=DataType.VARCHAR,
            max_length=50,
            is_primary=True,
            auto_id=False,
        ),
        FieldSchema(name=Columns.IS_ENABLED.value, dtype=DataType.BOOL),
        FieldSchema(name=Columns.COUNTRY_CODES.value, dtype=DataType.JSON),
        FieldSchema(name=Columns.APPLICABLE_FOR.value, dtype=DataType.JSON),
        FieldSchema(name=Columns.EMBEDDING.value, dtype=DataType.FLOAT_VECTOR, dim=MODEL_DIM),
    ]
    schema = CollectionSchema(
        fields=fields, description="search recipes", enable_dynamic_field=True
    )

    index_params = MilvusClient.prepare_index_params()
    index_params.add_index(
        field_name=Columns.EMBEDDING.value,
        index_type=IndexType.IVF_FLAT,
        metric_type=MetricType.IP,
        params={"nlist": 1536}
    )

    client.create_collection(
        collection_name,
        id_type="string",
        vector_field_name=Columns.EMBEDDING.value,
        metric_type=MetricType.IP,
        schema=schema,
        index_params=index_params
    )

It does result in creation of an IVF_FLAT IP index but the nlist isn't getting set.

Expected Behavior

The nlist should get set as well.

Steps To Reproduce

Use the above piece of code for collection and index creation.

Milvus Log

No logs.

Anything else?

No.

[afzalIbnSH]

This is a pymilvus issue