Related pages:

The JavaScript Agent collects and sends information to the EUM Server via a beacon, either through Cross-Origin Resource Sharing (CORS) or an image beacon which returns a small, transparent .gif file.

If you want the Agent to only use CORS to transport the beacon, you can turn off the image beacon request mechanism. To turn off the image beacon request, add the following snippet to your HTML preceding the injected adrum.js script:

<head>
    <script type='text/javascript' charset='UTF-8'>
       (function (cfg) {
           if (cfg.beacon) cfg.beacon.neverSendImageBeacon = true;
           else cfg.beacon = { neverSendImageBeacon: true };
        })(window['adrum-config'] || (window['adrum-config'] = {}));
    </script>
    <script src='//cdn.appdynamics.com/adrum/adrum-latest.js' type='text/javascript' charset='UTF-8'></script>
    ...
</head>