 The Checkpointer is a daemon that periodically wakes up
 * up (determined by the schedule specified in the configuration),
 * triggers a periodic checkpoint and then goes back to sleep.
 * 
 * The start of a checkpoint is triggered by one of the two factors:
 * (1) time or (2) the size of the edits file.
 The Checkpointer is a daemon that periodically wakes up
 * up (determined by the schedule specified in the configuration),
 * triggers a periodic checkpoint and then goes back to sleep.
 * 
 * The start of a checkpoint is triggered by one of the two factors:
 * (1) time or (2) the size of the edits file. | Checkpointer.java