private void startAsyncFlusher() {
    final String thName =
        String.format("Asynchronous disk writer for region %s", getName());
    flusherThread = new LoggingThread(thName, new FlusherThread(this));
    flusherThread.start();
  }
How many threads are waiting to do a put on asyncQueue?
geode-core/src/main/java/org/apache/geode/internal/cache/DiskStoreImpl.java