I am currently running my application against the standalone server. I will occassionally get 502 Proxy errors on the HTTP response. Capture from wireshark below:
502 Proxy Error
Date: Thu, 18 Feb 2016 00:33:30 GMT
Server: Apache
X-Frame-Options: SAMEORIGIN
Content-Length: 408
Keep-Alive: timeout=5, max=100
Connection: Keep-Alive
Content-Type: text/html; charset=iso-8859-1
<!DOCTYPE HTML PUBLIC “-//IETF//DTD HTML 2.0//EN”>
<html><head>
<title>502 Proxy Error</title>
</head><body>
<h1>Proxy Error</h1>
<p>The proxy server received an invalid
response from an upstream server.<br />
The proxy server could not handle the request <em>POST /api/v1/data/ms</em>.<p>
Reason: <strong>Error reading from remote server</strong></p></p>
</body></html>