title: Remove a certain json field using logstash
body: <p>I need to remove entries having key as 404. My current filter doesn't seem to work. </p>
  
  <p>I need to only remove the field and not the entire row.</p>
  
  <pre><code>  if [net][status] == "404" {
  mutate {
    remove_field =&gt; [ "[url][queryString]" ]
  }
  }
  </code></pre>