public void stopTask() {
    LOG.info("Sending interrupt to stop the worker thread");
    worker.interrupt(); // TODO interrupt often gets swallowed, do what else?
  }
If the worker is doing a task i.e. splitting a log file then stop the task. It doesn't exit the
worker thread.
hbase-server/src/main/java/org/apache/hadoop/hbase/regionserver/SplitLogWorker.java