public int getRetryEventQueueSize() {
    return retryEventQueue.size();
  }
Add failure {@link EnrichedEvent}s to retry queue.

@param events {@link EnrichedEvent}s to retry
iotdb-core/datanode/src/main/java/org/apache/iotdb/db/pipe/connector/protocol/thrift/async/IoTDBDataRegionAsyncConnector.java