private static int canceledCount = 0;
public StandbyCheckpointer(Configuration conf, FSNamesystem ns)
throws IOException {
this.namesystem = ns;
this.checkpointConf = new CheckpointConf(conf);
this.thread = new CheckpointerThread();
this.uploadThreadFactory = new ThreadFactoryBuilder().setDaemon(true)
.setNameFormat("TransferFsImageUpload-%d").build();
setNameNodeAddresses(conf);