My Xenforo Site’s initial take on image proxy had it’s problems. The initial idea was that the images wouldn’t actually be on my server, but proxied through my site to it’s original source. I still prefer that approach but it had a few issues that will likely be resolved in the coming months.
For now, I’m using the new features in 1.3 to proxy the image to my server, which is almost doubling my server’s disk space utilization. However, I’ve also started caching most new attachments to the CDN as well.
Things were going well from an end-user perspective, but a few days ago I noticed that the CDN was taking full 1Gig bandwidth hits at least once per day. Also switched over to mod_expires on my server’s cache expiration settings and that also appears to have improved both user experience and CDN utilization.
Will likely move to a new server next month, using my traditional config, but definitely moving closer to a full distributed computing infrastructure.