private void checkNodesAlive() throws JMSException {
long timestamp = System.currentTimeMillis();
long timeout = timestamp - timeoutExpiration;
for (Iterator i = keepAliveMap.entrySet().iterator();i.hasNext();) {
Map.Entry entry = (Map.Entry) i.next();
SynchronizedLong activeTime = (SynchronizedLong) entry.getValue();
if (activeTime.get() < timeout) {
String name = entry.getKey().toString();
removeService(name);
log.warn(serviceName + " Expiring node: " + name);
}
}