I've installed APC on my server to improve performance since i have too many db queries executing. So I've set variable in apc_store('example','333',600) (this should be 600 seconds) and I can see that it is working sporadically. Meaning sometimes it does and sometimes it doesnt show me files from cache. I've informed a little and found out that it is due some mmap or FastCGI (im not that familiar with that field).
How can this be handled, and what are benefits/consequences ?