Fluentd fails to deliver message with Server returned nothing (no headers, no data)

Issue

• Fluentd fails to deliver messages with Server returned nothing (no headers, no data):

  2020-12-17 10:55:20 +0000 [warn]: [default] failed to flush the buffer. retry_time=0 next_retry_seconds=2020-12-17 10:55:21 +0000 chunk="5b6a6c201a4409bc30579ed2a74b3f6f" error_class=Fluent::Plugin::ElasticsearchOutput::RecoverableRequestFailure error="could not push logs to Elasticsearch cluster ({:host=>\"elasticsearch.openshift-logging.svc.cluster.local\", :port=>9200, :scheme=>\"https\", :user=>\"fluentd\", :password=>\"obfuscated\"}): Server returned nothing (no headers, no data)"
  

• Some times Fluentd re-tries and succeeds:

  2020-12-17 10:55:23 +0000 [warn]: [default] retry succeeded. chunk_id="5b6a6c201a4409bc30579ed2a74b3f6f"