# Service Specific Runtime Configuration

The JMS service configuration allows you to specify to runtime behaviors:

* the amount of time a response message can remain unreceived before the JMS broker can delete it.

* the client identifier used when creating and accessing durable subscriptions.

The jms:serverConfig element is used to specify the service runtime configuration. This element's attributes, listed below, specify the configuration values that control the service's runtime behavior.

| Attribute | Description |
| --- | --- |
| messageTimeToLive | Specifies the amount of time, in milliseconds, that a response can remain<br>unread before the JMS broker is allowed to delete it. The default is 0 which<br>specifies that the message can live forever. |
| durableSubscriptionClientId | Specifies the client identifier the endpoint uses to create and access<br>durable subscriptions. |

The following example shows a configuration fragment that sets the service endpoint's response lifetime to 500 milliseconds and its durable subscription client identifier to jms-test-id .

JMS Service Endpoint Runtime Configuration

```
<jms:destination 
   id="{http://cxf.apache.org/jms_endpt}HelloJMSPort.jms-destination">
   <jms:address ... >
      ...
   </jms:address>
   <jms:serverConfig messageTimeToLive="500"
      durableSubscriptionClientId="jms-test-id" />
</jms:destination>
```