title: fluentd elasticsearch plugin - The client is unable to verify that the server is Elasticsearch
body: <p>I want to send some nginx logs from fluentd to elasticsearch , however,  fluentd is unable to start due to following error message:</p>
  <p><strong>The client is unable to verify that the server is Elasticsearch. Some functionality may not be compatible if the server is running an unsupported product.</strong></p>
  <p><strong>[error]: #0 unexpected error error_class=Elasticsearch::UnsupportedProductError error=&quot;The client noticed that the server is not Elasticsearch and we do not support this unknown product.&quot;</strong></p>
  <p><a href="https://i.stack.imgur.com/x8R1f.png" rel="nofollow noreferrer"><img src="https://i.stack.imgur.com/x8R1f.png" alt="enter image description here" /></a></p>
  <p>This is my fluentd config :</p>
  <pre><code>&lt;source&gt;
    @type tail  
      &lt;parse&gt;    
        @type nginx 
      &lt;/parse&gt;  
    path /tmp/lab4/nginx/access.log  
    pos_file /tmp/lab4/nginx/access.po
    tag nginx.access
  &lt;/source&gt;
  
  &lt;match nginx.**&gt;
   @type elasticsearch
   scheme http
   host 192.168.1.154 
   port 9200 
   with_transporter_log true
   @log_level debug
  &lt;/match&gt;
  </code></pre>
  <p>If I do a curl <a href="http://192.168.1.154:9200" rel="nofollow noreferrer">http://192.168.1.154:9200</a> , I can see a response from Elasticsearch with the system version and other info .</p>
  <p>For reference I am using :</p>
  <ul>
  <li>fluentd version 1.14.5</li>
  <li>fluentd elastic-search-plugin 5.2.0</li>
  <li>elastic-search 7.12.0</li>
  </ul>
  <p>Any idea on what I am doing wrong ?</p>