title: fingerprint in logstash filter option not working properly?
body: <p>I have used below code but its only inserting one record to ES .</p>
  <pre><code>filter {
    fingerprint {
      target =&gt; &quot;document_id&quot;
      method =&gt; &quot;SHA256&quot;
      key =&gt; &quot;9ced3827c6a1c9dafac6da9abac41386ba1038ac95b3a865a0951bc2e948c58c&quot;
    }
  }
  
  output {
    elasticsearch {
      host =&gt; localhost
      document_id =&gt; &quot;%{document_id}&quot;
    }
  }
  </code></pre>
  <p>Please point out the mistake below I have approx 200k records in my sql which i am importing to ES. I want unique ids for each record using this fingerprint.</p>