Rollover alias not pointing to the rolled over index

Plugins Index Management
1

Hi team!
After reading through the docs attempted the rollover using ISM policy as follows. But it seems the index does get rolled over from test-000001 to test-000002 but keeps writing to test-000001 and the index keeps growing. Here are the steps I followed:

1] Created a policy:

{
    "policy": {
        "policy_id": "rollover_policy",
        "description": "Rollover test",
        "last_updated_time": 1597680827746,
        "schema_version": 1,
        "error_notification": null,
        "default_state": "hot",
        "states": [
            {
                "name": "hot",
                "actions": [
                    {
                        "retry": {
                            "count": 10,
                            "backoff": "exponential",
                            "delay": "1h"
                        },
                        "rollover": {
                            "min_size": "300gb"  
                        }
                    }
                ],
                "transitions": [
                    {
                        "state_name": "warm",
                        "conditions": {
                            "min_index_age": "5d"
                        }
                    }
                ]
            },
            {
                "name": "warm",
                "actions": [
                    {
                        "retry": {
                            "count": 5,
                            "backoff": "exponential",
                            "delay": "1h"
                        },
                        "warm_migration": {}
                    }
                ],
                "transitions": [
                    {
                        "state_name": "delete",
                        "conditions": {
                            "min_index_age": "10d"
                        }
                    }
                ]
            },
            {
                "name": "delete",
                "actions": [
                    {
                        "delete": {}
                    }
                ],
                "transitions": []
            }
        ]
    }
}

2] Created an index and attached the policy to it:

PUT test-000001
{
  "settings": {
    "opendistro.index_state_management.policy_id": "rollover_policy",
    "opendistro.index_state_management.rollover_alias": "demo"
  },
  "aliases": {
    "demo": {
      "is_write_index": true
    }
  }
}

3] Registered a template (for upcoming indices to have the same policy):

 PUT _template/template_1
{
  "index_patterns": [
    "test-*"
  ],
  "settings": {
    "index": {
      "opendistro": {
        "index_state_management": {
          "policy_id": "rollover_policy",
          "rollover_alias": "demo"
        }
      }
    }
  }
}

Tried a couple of variations like from the Index Management (IM) tab in Kibana, attaching the policy and the rollover_alias to the index: test-000001 as mentioned here But it seems I am missing some key step which is not making the rollover_alias point to the rolled over index

Here is the logstash conf:

amazon_es {
	   hosts => ["http://myelasticsearch"]
	   index => "test-000001"
      
}

Observation:
Docs are successfully ingested to the index: test-000001 and after the primary reaches ~300gb, a new index gets created test-000002 however, docs continue to be ingested in test-000001 (Apart from this, the migration to warm and then delete all works smooth)

Any help would be appreciated.

3

After a few tries over the weekend, got the above to work by specifying the rollover_alias name in the logstash.conf file instead of the index name.

amazon_es {
	   hosts => ["http://myelasticsearch"]
	   index => "demo"  
}