When the EJB pools are configured with 'strictMaximumSize' set to true, if an Exception is thrown from the ejbCreate method of the bean being created to service the request the permit is not returned before the Exception is thrown to the calling client.

If this keeps happening till all permits are exhausted the clients will start to get the error: -

'Failed to acquire the pool semaphore' thrown as an EJBException from the get method of the AbstractInstancePool.