title: Cassandra PHP All connections on all I/O threads are busy
body: <p>I have a problem with getting results from cassandra through PHP. The error comes randomly (sometimes after 30 reloads, sometimes few times in a row). I'm using DataStax PHP Driver 1.30 and PHP 7.0. </p>
  
  <p>The Error </p>
  
  <blockquote>
    <p>An uncaught Exception was encountered
        Type: Cassandra\Exception\RuntimeException
        Message: All connections on all I/O threads are busy</p>
  </blockquote>
  
  <p>My connection constructor:</p>
  
  <pre><code>$this-&gt;cluster  = Cassandra::cluster()
      &gt;withContactPoints('172.16.0.31')
      -&gt;build();
  $this-&gt;session  = $this-&gt;cluster-&gt;connect($this-&gt;keyspace);
  </code></pre>
  
  <p>My get table function:</p>
  
  <pre><code>$sql = new Cassandra\SimpleStatement("SELECT * FROM {$table}");
  $future = $this-&gt;session-&gt;executeAsync($sql);
  $result = $future-&gt;get();
  return $result;
  </code></pre>
  
  <p>Does anyone know how to solve this problem?</p>