title: illegal_argument_exception: index.lifecycle.rollover_alias [metricbeat-6.8.4-alias] does not point to index [metricbeat-6.8.4-2020.02.24]
body: <p>currently looking for help about setup ilm, i have setup the template, index alias and policy as below</p>
  
  <pre><code>PUT metricbeat-6.8.4-alias-000001
  {
    "aliases": {
      "metricbeat-6.8.4-alias": {
        "is_write_index": true
      }
    }
  }
  
  PUT _template/metricbeat-6.8.4-alias
  {
    "index_patterns": ["metricbeat-6.8.4-*"],                 
    "settings": {
      "number_of_shards": 1,
      "number_of_replicas": 1,
      "index.lifecycle.name": "Delete_Index",      
      "index.lifecycle.rollover_alias": "metricbeat-6.8.4-alias"    
    }
  }
  </code></pre>
  
  <p>but still error ocurred like below</p>
  
  <pre><code>illegal_argument_exception: index.lifecycle.rollover_alias [metricbeat-6.8.4-alias] does not point to index [metricbeat-6.8.4-2020.02.24]
  </code></pre>
  
  <p>looking for help how i setup correcly the ilm ?
  thanks</p>