title: How to get logstash to store all of the words from one field as an array in another field
body: <p>I am struggling with the filters in Logstash.</p>
  
  <p>I am trying to take a well structured json stream (I am using a twitter feed for test data) and augment the data. One of our needs is to take an existing field, such as message, and store all of the unique tokens (in this case simple space delimited words).</p>
  
  <p>In the long run we would like to be able to use elastic search analyzers to break down the message into normalized chunks (using stemming, stopwords, toLower, etc...)</p>
  
  <p>The desired goal is to take something like:
  {
      "@timestamp":"2016-10-12T19:01:33.000Z",
      "message":"The quickest Brown fox",
      ...
  }</p>
  
  <p>and get something like:
  {
      "@timestamp":"2016-10-12T19:01:33.000Z",
      "message":"The quickest Brown fox",
      "tokens":["The", "quickest", "Brown", "fox"],
      ...
  }</p>
  
  <p>and ultimately like this:
  {
      "@timestamp":"2016-10-12T19:01:33.000Z",
      "message":"The quickest Brown fox",
      "tokens":["quick", "brown", "fox"],
      ...
  }</p>
  
  <p>I feel like I am pounding my head against a wall. Any help pointing me in the right direction would be appreciated.</p>
  
  <p>Thanks</p>