How to combine characters to create custom pattern in GROK
<p>I'm new to logstash and grok and have a question regarding a pattern.</p>

<blockquote>
  <p>Jul 26 09:46:37 </p>
</blockquote>

<p>The above content contains <code>%{MONTH} %{MONTHDAY} %{TIME}</code> and white spaces.</p>

<p>I need to know how to combine all these and create a pattern <code>%{sample_timestamp}</code></p>

<p>Thanks!</p>