code: private void checkQueueSize() {
          int queueSize = getQueueSize();
          if (SEND_QUEUE_SIZE_WARNING_THRESHOLD > 0 && queueSize >= SEND_QUEUE_SIZE_WARNING_THRESHOLD) {
              logger.warn("The Gerrit send commands queue contains {} items!"
                      + " Something might be stuck, or your system can't process the commands fast enough."
                      + " Try to increase the number of sending worker threads."
                      + " Current thread-pool size: {}",
                      queueSize, executor.getPoolSize());
              logger.info("Nr of active pool-threads: {}", executor.getActiveCount());
          }
      }
docs: Checks queue size.