title: Grok with Missing values using logstash
body: <p>I am trying to grok this inputs with logstash,</p>
  
  <pre><code>Nicolas Lauri 34 
  Nicolas 33  #there is one space and it not works.
  Nicolas  33 #there are two spaces and it works.
  </code></pre>
  
  <p>with this pattern</p>
  
  <pre><code>(%{WORD:firstname})? (%{WORD:lastname})? (%{NUMBER:age})?
  </code></pre>
  
  <p>Using the ()? I ignore missing values and say that are optionals, but the problem is we must put spaces between value to make it works.</p>
  
  <p>i mean if i have this input:</p>
  
  <pre><code>Nicolas  19
  </code></pre>
  
  <p>i must put exactly two spaces between Nicolas et 19 to grok it correctly.</p>
  
  <p>What should i do to avoid putting spaces ?</p>