public org.apache.flink.table.descriptors.Elasticsearch disableFlushOnCheckpoint() {
		internalProperties.putBoolean(CONNECTOR_FLUSH_ON_CHECKPOINT, false);
		return this;
	}
Disables flushing on checkpoint. When disabled, a sink will not wait for all pending action
requests to be acknowledged by Elasticsearch on checkpoints.

<p>Note: If flushing on checkpoint is disabled, a Elasticsearch sink does NOT
provide any strong guarantees for at-least-once delivery of action requests.
elasticsearch5-xh/elasticsearch5-xh-sink/src/main/java/org/apache/flink/table/descriptors/Elasticsearch.java