protected List<String> filterMissingFiles(List<String> incrBackupFileList) throws IOException {
    List<String> list = new ArrayList<>();
    for (String file : incrBackupFileList) {
      Path p = new Path(file);
      if (fs.exists(p) || isActiveWalPath(p)) {
        list.add(file);
      } else {
        LOG.warn("Can't find file: " + file);
      }
    }
    return list;
  }
Incremental backup implementation. See the {@link #execute() execute} method.
hbase-backup/src/main/java/org/apache/hadoop/hbase/backup/impl/IncrementalTableBackupClient.java