title: How does a connection pool in MongoDB with pymongo driver?
body: <p>I'm using mongodb with pymongo driver on gevent based framework. I don't understand working pool connection. I'm creating a new connection instance on every request:</p>
  
  <pre><code>connection = MongoClient(host='localhost', port=27017, use_greenlets=True)
  </code></pre>
  
  <p>Actually connection taken from a pool of?</p>
  
  <p>Now, if I take the connection so:</p>
  
  <pre><code>connection = MongoClient(host='localhost', port=27017)
  </code></pre>
  
  <p>This is connection taken from with the same pool? 
  What happens if you make a call MongoClient different arguments?</p>