docs/admin-manual/open-api/fe-http/set-config-action.md

---
{
    "title": "Set Config Action",
    "language": "en"
}
---

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# Set Config Action

## Request

`GET /api/_set_config`

## Description

Used to dynamically set the configuration of FE. This command is passed through the `ADMIN SET FRONTEND CONFIG` command. But this command will only set the configuration of the corresponding FE node. And it will not automatically forward the `MasterOnly` configuration item to the Master FE node.
    
## Path parameters

None

## Query parameters

* `confkey1=confvalue1`

    Specify the configuration name to be set, and its value is the configuration value to be modified.
    
* `persist`

     Whether to persist the modified configuration. The default is false, which means it is not persisted. If it is true, the modified configuration item will be written into the `fe_custom.conf` file and will still take effect after FE is restarted.

* `reset_persist`
    Whether or not to clear the original persist configuration only takes effect when the persist parameter is true. For compatibility with the original version, reset_persist defaults to true.  
	If persist is set to true and reset_persist is not set or reset_persist is true, the configuration in the `fe_custom.conf` file will be cleared before this modified configuration is written to `fe_custom.conf`.  
	If persist is set to true and reset_persist is false, this modified configuration item will be incrementally added to `fe_custom.conf`.


## Request body

None

## Response

```
{
	"msg": "success",
	"code": 0,
	"data": {
		"set": {
			"key": "value"
		},
		"err": [
			{
		       "config_name": "",
		       "config_value": "",
		       "err_info": ""
		    }
		],
		"persist":""
	},
	"count": 0
}
```

The `set` field indicates the successfully set configuration. The `err` field indicates the configuration that failed to be set. The `persist` field indicates persistent information.
    
## Examples

1. Set the values of `storage_min_left_capacity_bytes`, `replica_ack_policy` and `agent_task_resend_wait_time_ms`.

    ```
    GET /api/_set_config?storage_min_left_capacity_bytes=1024&replica_ack_policy=SIMPLE_MAJORITY&agent_task_resend_wait_time_ms=true
    
    Response:
    {
    "msg": "success",
    "code": 0,
    "data": {
        "set": {
            "storage_min_left_capacity_bytes": "1024"
        },
        "err": [
            {
                "config_name": "replica_ack_policy",
                "config_value": "SIMPLE_MAJORITY",
                "err_info": "Not support dynamic modification."
            },
            {
                "config_name": "agent_task_resend_wait_time_ms",
                "config_value": "true",
                "err_info": "Unsupported configuration value type."
            }
        ],
        "persist": ""
    },
    "count": 0
    }

	storage_min_left_capacity_bytes  Successfully;    
	replica_ack_policy  Failed, because the configuration item does not support dynamic modification.  
	agent_task_resend_wait_time_ms  Failed, failed to set the boolean type because the configuration item is of type long.
    ```

2. Set `max_bytes_per_broker_scanner` and persist it.

    ```
    GET /api/_set_config?max_bytes_per_broker_scanner=21474836480&persist=true&reset_persist=false
    
    Response:
    {
    "msg": "success",
    "code": 0,
    "data": {
        "set": {
            "max_bytes_per_broker_scanner": "21474836480"
        },
        "err": [],
        "persist": "ok"
    },
    "count": 0
    }
	```

	The fe/conf directory generates the fe_custom.conf file:
	```
	#THIS IS AN AUTO GENERATED CONFIG FILE.
    #You can modify this file manually, and the configurations in this file
    #will overwrite the configurations in fe.conf
    #Wed Jul 28 12:43:14 CST 2021
    max_bytes_per_broker_scanner=21474836480
    ```