Silently ignore unavailable data source at application start up

Silently ignore unavailable data source at application start up

I have an EJB application which uses JPA 2.0 on Glassfish 3.1.2 (provider
is EclipseLink). When the database is down the application does not start.
This is because EclipseLink does some initial verification.
Is there a way that the application starts even if the database is down?
Background: The resource being unavailable comes not into play until the
first business function is called which accesses the database. From
application startup till the first business function call there is a time
window where the database may be started.