# ISM policy not applying to index

**URL:** <https://forum.opensearch.org/t/ism-policy-not-applying-to-index/28312>\
**Category:** OpenSearch\
**Tags:** troubleshoot\
**Created:** [October 2, 2026, 12:45pm UTC](https://forum.opensearch.org/t/ism-policy-not-applying-to-index/28312 "2026-10-02T12:45:56Z")\
**Posts on this page:** 4\
**Page:** 1

<div class="post-metadata">

**Author:** ![GuyS](https://avatars.discourse-cdn.com/v4/letter/g/977dab/32.png) [@GuyS](https://forum.opensearch.org/u/GuyS)\
**Post date:** [October 2, 2026, 12:45pm UTC](https://forum.opensearch.org/t/ism-policy-not-applying-to-index/28312/1 "2026-10-02T12:45:56Z")

</div>

**Versions** (relevant - OpenSearch/Dashboard/Server OS/Browser):3.7

**Describe the issue** :ISM Policy is not being applied to data stream

**Configuration** :

```auto
{
  "_id": "insight2",
  "_version": 1,
  "_seq_no": 180323,
  "_primary_term": 2,
  "policy": {
    "policy_id": "insight2",
    "description": "A sample description of the policy",
    "last_updated_time": 1790619351460,
    "schema_version": 29,
    "error_notification": null,
    "default_state": "hot",
    "states": [
      {
        "name": "hot",
        "actions": [
          {
            "retry": {
              "count": 3,
              "backoff": "exponential",
              "delay": "1h"
            },
            "rollover": {
              "min_size": "10gb",
              "min_doc_count": 2000000000,
              "min_index_age": "5d",
              "min_primary_shard_size": "15gb",
              "copy_alias": false
            }
          }
        ],
        "transitions": [
          {
            "state_name": "cold",
            "conditions": {
              "min_index_age": "7d"
            }
          }
        ]
      },
      {
        "name": "cold",
        "actions": [
          {
            "retry": {
              "count": 0,
              "backoff": "exponential",
              "delay": "1h"
            },
            "read_only": {}
          }
        ],
        "transitions": [
          {
            "state_name": "delete",
            "conditions": {
              "min_index_age": "10d"
            }
          }
        ]
      },
      {
        "name": "delete",
        "actions": [
          {
            "retry": {
              "count": 3,
              "backoff": "exponential",
              "delay": "1h"
            },
            "delete": {}
          }
        ],
        "transitions": []
      }
    ],
    "ism_template": [
      {
        "index_patterns": [
          ".ds-insightlogs*"
        ],
        "priority": 1,
        "last_updated_time": 1790619351460
      }
    ]
  }
}

```

**Relevant Logs or Screenshots** :

```auto
{
  "index_templates": [
    {
      "name": "insightlogs-template",
      "index_template": {
        "index_patterns": [
          "insightlogs*"
        ],
        "template": {
          "settings": {
            "index": {
              "default_pipeline": "insightlogs-pipeline",
              "knn": "true",
              "opendistro": {
                "index_state_management": {
                  "policy_id": "insight2"
                }
              },
              "number_of_shards": "1",
              "number_of_replicas": "0",
              "plugins": {
                "index_state_management": {
                  "policy_id": "insight2"
                }
              }
            }
          },
          "mappings": {
            "properties": {
              "auth-username_vector": {
                "method": {
                  "engine": "lucene",
                  "space_type": "l2",
                  "name": "hnsw"
                },
                "type": "knn_vector",
                "dimension": 384
              },
              "device-name": {
                "type": "keyword"
              },
              "auth-username": {
                "type": "text"
              },
              "cppm-node": {
                "type": "keyword"
              },
              "nas-port": {
                "type": "keyword"
              },
              "nas-id": {
                "type": "keyword"
              },
              "profiles": {
                "type": "keyword"
              },
              "session_id": {
                "type": "keyword"
              },
              "error-code": {
                "type": "integer"
              },
              "mac": {
                "type": "keyword"
              },
              "hostname": {
                "type": "keyword"
              },
              "protocol": {
                "type": "keyword"
              },
              "@timestamp": {
                "type": "date"
              },
              "nas-ip": {
                "type": "ip"
              },
              "auth-method": {
                "type": "keyword"
              },
              "service": {
                "type": "keyword"
              },
              "device-family": {
                "type": "keyword"
              },
              "host": {
                "type": "keyword"
              },
              "device-category": {
                "type": "keyword"
              },
              "timestamp": {
                "format": "yyyy-MM-dd HH:mm:ss.S||yyyy-MM-dd HH:mm:ss||strict_date_optional_time",
                "type": "date"
              },
              "username": {
                "type": "keyword"
              }
            }
          }
        },
        "composed_of": [],
        "priority": 100,
        "_meta": {
          "flow": "simple"
        },
        "data_stream": {
          "timestamp_field": {
            "name": "@timestamp"
          }
        }
      }
    }
  ]
}

```

---

<div class="post-metadata">

**Author:** ![Yanlin](https://sea1.discourse-cdn.com/flex019/user_avatar/forum.opensearch.org/yanlin/32/10286_2.png) [@Yanlin](https://forum.opensearch.org/u/Yanlin)\
**Post date:** [October 2, 2026, 4:20pm UTC](https://forum.opensearch.org/t/ism-policy-not-applying-to-index/28312/2 "2026-10-02T16:20:07Z")

</div>

Hi @GuyS,

I reproduced this on OpenSearch 3.7.0.

The `ism_template` pattern `.ds-insightlogs*` did not result in the data stream backing index being managed by ISM. After changing the pattern in the ISM policy to match the data stream name:

```json
"index_patterns": ["insightlogs*"]

```

the policy was successfully applied to the newly created backing index.

Could you try changing the pattern from `.ds-insightlogs*` to `insightlogs*` and check whether newly created backing indices are managed by ISM?

Kind regards,

Yanlin

---

<div class="post-metadata">

**Author:** ![GuyS](https://avatars.discourse-cdn.com/v4/letter/g/977dab/32.png) [@GuyS](https://forum.opensearch.org/u/GuyS)\
**Post date:** [October 2, 2026, 6:13pm UTC](https://forum.opensearch.org/t/ism-policy-not-applying-to-index/28312/3 "2026-10-02T18:13:28Z")

</div>

Thank you Yanlin !!!

---

<div class="post-metadata">

**Author:** ![Yanlin](https://sea1.discourse-cdn.com/flex019/user_avatar/forum.opensearch.org/yanlin/32/10286_2.png) [@Yanlin](https://forum.opensearch.org/u/Yanlin)\
**Post date:** [October 6, 2026, 12:25pm UTC](https://forum.opensearch.org/t/ism-policy-not-applying-to-index/28312/4 "2026-10-06T12:25:08Z")

</div>

Hi @GuyS,

One additional note regarding the index template configuration: `opendistro.index_state_management.policy_id` is deprecated in favor of `ism_template`. The `plugins.index_state_management.policy_id` field is also deprecated and retained in API responses for backward compatibility. In my tests, both settings were inherited by the data stream backing index, but their presence alone did not confirm that the index was being managed by ISM. You can use the Explain API to verify whether the policy is actually attached:

```auto
GET _plugins/_ism/explain/{index}?pretty

```

Kind regards,

Yanlin