We started using the chat plugin in bottom-corner (site-wide mode), but discovered that (due to traffic volume) the load imposed on the server by the AJAX hook is too great, so we disabled corner mode. We just put chat on a dedicated http://www.site.com/chat/ static page.
The problem is, our server load is still high (even though its disabled site-wide and only employed on a static page nobody is viewing!)As of this writing we're getting 98 hits/sec on wordpress-chat/wpmudev-chat-ajax.php, with an average load-average of 2.8 (peaking at 5.7 in last 30 hrs) due to the execution of this PHP code. By contrast, our server load is usually about 0.3, maybe 0.6 when we get busy (thanks to W3TC full-page caching).
We had thought that disabling site-wide mode and dumping the page cache would have quit serving code that hits this AJAX hook, and that residual hits were due to client-side cached copies — but looking at the page source there is still mention of the AJAX URL, and the hit-rate is fairly stable (modulo usual diurnal traffic).
How do we employ this plugin without loading the server with unnecessary AJAX requests and how can we squash the traffic we're currently getting?