code: protected void startCacheInvalidator() {
          polling = true;
          Thread thread = new Thread(new Runnable() {
              @Override
              public void run() {
                  // Wait for 30s on startup before starting to poll.
                  try { Thread.sleep(startupDelayMillis); } catch (InterruptedException e1) { e1.printStackTrace(); }
  
                  while (polling) {
                      try { Thread.sleep(pollIntervalMillis); } catch (Exception e) { e.printStackTrace(); }
                      checkCacheVersion();
                  }
              }
          }, "ESRegistryCacheInvalidator"); //$NON-NLS-1$
          thread.setDaemon(true);
          thread.start();
      }
docs: Starts up a thread that polls the ES store for updates.