A full backup — in other words, one where you copy all of the files from your system — would obviously capture everything, but it can be an expensive way of backing up your information.
Since the slave KDC is meant for backing up the master KDC in an emergency, the slave KDC might need to use the read-write copy.
因为从KDC用于在紧急情况下替代主kdc,所以从KDC可能需要使用可读写拷贝。
3
For the new CopyOnWriteArrayList and CopyOnWriteArraySet classes, all mutable operations make a copy of the backing array first, make the change to the copy, and then replace the copy.