# Obtaining Default Parameters of a DB Instance

#### Function

This API is used to obtain default parameters of a specified DB instance.

#### URI

- URI format

  PATH: /v1.0/{project_id}/instances/{instanceId}/configuration

  Method: GET

- Parameter description

  Table 1 Parameter description
  Name | Mandatory | Description
  --- | --- | ---
  project_id | Yes | Specifies the project ID of a tenant in a region.
  instanceId | Yes | Specifies the DB instance ID.

- Restrictions

  Currently, only the DB engines MySQL and PostgreSQL are supported by the API.

#### Request

None

#### Normal Response

- Parameter description

  Table 2 Parameter description
  Name | Type | Description
  --- | --- | ---
  instance | List data structure. For details, see Table 3. | Indicates the parameter information of the specified DB instance.

  Table 3 instance field data structure description
  Name | Type | Description
  --- | --- | ---
  configuration | Dictionary data structure. For details, see Table 4. | Indicates the default parameter value.

  Table 4 configuration field data structure description
  Name | Type | Description
  --- | --- | ---
  key | String | Indicates the parameter name. For example, in "max_connections": "10", the key is max_connections.
  value | String | Indicates the parameter value. For example, in "max_connections": "10", the value is 10.

- Response example

      {
          "instance": {
              "configuration": {
                  "basedir": "/usr",
                  "connect_timeout": "15",
                  "datadir": "/var/lib/mysql",
                  "default_storage_engine": "innodb",
                  "innodb_buffer_pool_size": "600M",
                  "innodb_data_file_path": "ibdata1:10M:autoextend",
                  "innodb_file_per_table": "1",
                  "innodb_log_buffer_size": "25M",
                  "innodb_log_file_size": "50M",
                  "innodb_log_files_in_group": "2",
                  "join_buffer_size": "1M",
                  "key_buffer_size": "200M",
                  "local-infile": "0",
                  "max_allowed_packet": "4096K",
                  "max_connections": "400",
                  "max_heap_table_size": "64M",
                  "max_user_connections": "400",
                  "myisam-recover": "BACKUP",
                  "open_files_limit": "2048",
                  "pid_file": "/var/run/mysqld/mysqld.pid",
                  "port": "3306",
                  "query_cache_limit": "1M",
                  "query_cache_size": "32M",
                  "query_cache_type": "1",
                  "read_buffer_size": "512K",
                  "read_rnd_buffer_size": "512K",
                  "server_id": "334596",
                  "skip-external-locking": "1",
                  "sort_buffer_size": "1M",
                  "table_definition_cache": "1024",
                  "table_open_cache": "1024",
                  "thread_cache_size": "16",
                  "thread_stack": "192K",
                  "tmp_table_size": "64M",
                  "tmpdir": "/var/tmp",
                  "user": "mysql",
                  "wait_timeout": "120"
              }
      }
      }

#### Abnormal Response

For details, see Abnormal Request Results.

Parent topic: Parameter Configuration