do {
final Cacheable cached = next.getValue();
if(cached.getKey() != item.getKey()) {
final Collection old = (Collection) cached;
final Lock lock = old.getLock();
if (lock.attempt(Lock.READ_LOCK)) {
try {
if (cached.allowUnload()) {
if(pool.getConfigurationManager()!=null) { // might be null during db initialization
pool.getConfigurationManager().invalidate(old.getURI(), null);
}