OpenSearch Input

[AcidWeb]

Hello,
Currently, I'm trying to use Fluentd to forward logs stored in OpenSearch 1.3.5 to software that parses GELF format.
Apparently, I'm missing something obvious - I can get data flowing but Fluentd sends data in a loop. Instead only fresh records entire contents of indices are sent over and over.

<source>
  @type opensearch
  host X
  port 9200
  scheme https
  tag ABC
  index_name Y-*
  user Z
  password V
</source>

<match ABC>
  @type gelf
  host Y
  port 7074
  protocol udp
  <buffer>
    flush_interval 5s
  </buffer>
</match>