title: How to measure performance of Node.js service?
body: <p>There is a service Node.js that makes a useful calculations. It is <code>index.js</code> file.</p>
  <p>There is a queue of events. Another service reads these events and calls the first service.</p>
  <p>I wonder should I call node.js services separately like:</p>
  <pre><code>event1 -&gt; node index.js
  event2 -&lt; node index.js
  </code></pre>
  <p>Or run one node process and inside listen events and handle them:</p>
  <pre><code>run node.js
     event1 -&gt; handle
     event2 -&gt; handle
  </code></pre>
  <p>Or the third way:</p>
  <pre><code>run node.js (process 1)
     event1 -&gt; handle
     event2 -&gt; handle
  
  run node.js (process 2)
     event1 -&gt; handle
     event2 -&gt; handle
  </code></pre>
  <p>How to measure performance in this case and make a right decision?</p>