public void unlockDrain() {
    if (testHook != null) {
      testHook.doTestHook("PRE_RELEASE_DRAIN_LOCK");
    }
    synchronized (drainLock) {
      drainLocked = false;
    }
  }
returns the queue size calculated through stats
geode-core/src/main/java/org/apache/geode/internal/cache/tier/sockets/CacheClientProxy.java