# Dynamic Mapping

**URL:** <https://forum.opensearch.org/t/dynamic-mapping/23843>\
**Category:** OpenSearch\
**Tags:** discuss, troubleshoot, index-management\
**Created:** [March 19, 2025, 7:11pm UTC](https://forum.opensearch.org/t/dynamic-mapping/23843 "2025-03-19T19:11:19Z")\
**Posts on this page:** 4\
**Page:** 1

<div class="post-metadata">

**Author:** ![spookyOS](https://avatars.discourse-cdn.com/v4/letter/s/6bbea6/32.png) [@spookyOS](https://forum.opensearch.org/u/spookyOS)\
**Post date:** [March 19, 2025, 7:11pm UTC](https://forum.opensearch.org/t/dynamic-mapping/23843/1 "2025-03-19T19:11:19Z")

</div>

**Versions** (relevant - OpenSearch/Dashboard/Server OS/Browser):  
OS Serverless Stack Management: 2.0.2

**Describe the issue** :  
Updating the dynamic mapping for an existing index. I m trying to disable the dynamic mapping for an index using:  
PUT /X-index/\_settings  
{  
“index.mapper.dynamic”: false  
}  
But i m getting this error:

```auto
{
  "error": {
    "root_cause": [
      {
        "type": "illegal_argument_exception",
        "reason": "X-index Update to setting [index.mapper.dynamic] is not supported"
      }
    ],
    "type": "illegal_argument_exception",
    "reason": "X-index Update to setting [index.mapper.dynamic] is not supported"
  },
  "status": 400
}

```

Is the update to an existing index supported? I understood it is supported and will only apply to future datasets but doesnt seem so.

**Configuration** :

**Relevant Logs or Screenshots** :  
Attached above

---

<div class="post-metadata">

**Author:** ![pablo](https://sea1.discourse-cdn.com/flex019/user_avatar/forum.opensearch.org/pablo/32/10363_2.png) [@pablo](https://forum.opensearch.org/u/pablo)\
**Post date:** [March 20, 2025, 3:50pm UTC](https://forum.opensearch.org/t/dynamic-mapping/23843/2 "2025-03-20T15:50:28Z")

</div>

@spookyOS Try this instead

```auto
PUT my_index/_mapping
{
  "dynamic": false
}

```

```auto
{
  "my_index": {
    "aliases": {},
    "mappings": {
      "dynamic": "false"
    },
    "settings": {
      "index": {
        "replication": {
          "type": "DOCUMENT"
        },
        "number_of_shards": "1",
        "provided_name": "my_index",
        "creation_date": "1742485738574",
        "number_of_replicas": "1",
        "uuid": "auKWXlRsSOaRk_OA6i2zUw",
        "version": {
          "created": "136407927"
        }
      }
    }
  }
}

```

---

<div class="post-metadata">

**Author:** ![spookyOS](https://avatars.discourse-cdn.com/v4/letter/s/6bbea6/32.png) [@spookyOS](https://forum.opensearch.org/u/spookyOS)\
**Post date:** [March 21, 2025, 5:05pm UTC](https://forum.opensearch.org/t/dynamic-mapping/23843/3 "2025-03-21T17:05:56Z")

</div>

This worked. Thanks. I previously tried

```auto
PUT /my_index/_mapping
{
  "dynamic": false
}

```

But that didnt work .

---

<div class="post-metadata">

**Author:** ![KateWinslet](https://sea1.discourse-cdn.com/flex019/user_avatar/forum.opensearch.org/katewinslet/32/6694_2.png) [@KateWinslet](https://forum.opensearch.org/u/KateWinslet)\
**Post date:** [October 27, 2025, 9:56am UTC](https://forum.opensearch.org/t/dynamic-mapping/23843/4 "2025-10-27T09:56:25Z")

</div>

> [@spookyOS](#):
>
> **Versions** (relevant - OpenSearch/Dashboard/Server OS/Browser):  
> OS Serverless Stack Management: 2.0.2
> 
> **Describe the issue** :  
> Updating the dynamic mapping for an existing index. I m trying to disable the dynamic mapping for an index using:  
> PUT /X-index/\_settings  
> {  
> “index.mapper.dynamic”: false  
> }  
> But i m getting this error:
> 
> ```auto
> {
> "error": {
> "root_cause": [
> {
> "type": "illegal_argument_exception",
> "reason": "X-index Update to setting [index.mapper.dynamic] is not supported"
> }
> ],
> "type": "illegal_argument_exception",
> "reason": "X-index Update to setting [index.mapper.dynamic] is not supported"
> },
> "status": 400
> }
> 
> ```
> 
> Is the update to an existing index supported? I understood it is supported [Compass](https://compassdollartree.wixsite.com/schedule) and will only apply to future datasets but doesnt seem so.
> 
> **Configuration** :
> 
> **Relevant Logs or Screenshots** :  
> Attached above

Set your index mapping to disable dynamic fields, ensuring only predefined fields are allowed. This prevents Elasticsearch from automatically adding new fields and keeps your index structure consistent and controlled.