DB2 10.5 for Linux, UNIX, and Windows

Enabling or disabling a member subset

To control the ability of applications that are assigned to a member subset to access the database, you can enable or disable member subsets.

Before you begin

You must have an existing member subset.

About this task

By default, a member subset is enabled when created. When a member subset is disabled, applications that are assigned to the member subset are not allowed to establish new database connections. Attempts to establish a new database connection are rejected with an error.

Existing connections are not effected. If the application is using transaction-level workload balancing, disabling the application's assigned member subset is a QUIESCE operation. Existing transactions run to completion. When the DB2® Data Driver attempts to refresh the connection for new transactions, the connection attempt is rejected with an error.

Restrictions

DBADM or WLMADM authority is required.

Procedure

To block applications that are assigned to a member subset from accessing the database, use the WLM_ALTER_MEMBER_SUBSET routine to disable the member subset:
```
CALL SYSPROC.WLM_ALTER_MEMBER_SUBSET( 'subset-name',  'subset-attributes', '( add-or-drop-member-list )' )
```
where:
- subset-name is the member subset name.
- subset-attributes is set to '<enabled>no</enabled>'.
- add-or-drop-member-list is NULL.
For example, to disable member subset OLTP_SUBSET, enter:
```
CALL SYSPROC.WLM_ALTER_MEMBER_SUBSET( 'OLTP_SUBSET', '<enabled>no</enabled>, NULL )
```
Validate that the member subset is disabled by attempting to connect to the member subsets database alias. An error is expected.
To re-enable the member subset, use the WLM_ALTER_MEMBER_SUBSET routine. For example, to re-enable member subset OLTP_SUBSET enter:
```
CALL SYSPROC.WLM_ALTER_MEMBER_SUBSET( 'OLTP_SUBSET', '<enabled>yes</enabled>', NULL )
```
Validate that the member subset is enabled by connecting to the member subsets database alias. The connection succeeds.