We run WordTwit Pro and W3TC with Page Cache (memcached) and Browser Cache enabled. The thing is, after W3TC has been enabled for some time, my editors lose the TinyMCE GUI and the tabs won't even work int he post editor. However, during this same time, Administrators have no issues.
So I took a look at the source code and found this:
Fatal error: Allowed memory size of 134217728 bytes exhausted (tried to allocate 262144 bytes) in /home/inflexwe/public_html/wp-content/plugins/wordtwit-pro/include/post-box-functions.php on line 388
The above error stopped PHP dead in it's tracks and would not load anything else... in-turn failing to load the rest of the footer, where I believe TinyMCE is held.
The code the error is referencing can be found here: http://pastebin.com/7kxu0pYd
Line 8 is the line 388 the error is referring to, so an error on the foreach loop? Don't think so. Furthermore, if you look at the code before that line, as we devs do, you'll see that it's a solid block of code and properly constructed.
So my question is, why would Administrators not get the same error but Editors will? Furthermore, it's only trying to allocate less than 1MB of memory out of the 128MB it has... Also this only happens when we turn on MemCache in W3TC.
The reason I am posting this in W3TC is we've been around the block with BNC and as you can see, the code looks like it should. And before you ask, can "your rig handle this," here's hardware specs:
CPU: Dual Xeon E5506 Quad Core
Ram: 48GB DDR3 SDRAM
HDD: 1TB 7200 RPM SATA hard drive
We're serving nearly 10 mil views monthly with an average of 3-500 concurrent connections during peak hours. And roughly 1,000+ if a new CD is released. We employ an external database to save on server power and use W3TC to optimize it for the front-end user.