title: request pool for php curl
body: <p>My PHP server (A) needs to make an http request to another server (B) each time it's called.
  I'm familiar with the usual use case for using curl in PHP</p>
  
  <pre><code>$ch = curl_init();
  curl_setopt_array($ch, $curlOptions);
  $responseBody = curl_exec($ch);
  $curlErrorCode = curl_errno($ch);
  curl_close($ch);
  </code></pre>
  
  <p>However I'm calling the same server (B) every time. Is there a way to keep the connections between A and B open (keepalive)? Maybe some sort of connection pool?</p>