hi Billie,
The Hosted Edition is configured to log : requests, impressions, clicks
If you are not seeing any statistics, i'm personally thinking it has to do with the implementation of the adservers invocation code.
Hi Kevan,
Memcache would probably help! It's hard to determine what the best settings for your environment would be, but an important setting for sure is the max amount of connections it can accept (also for MySQL).
Also make sure you have OPcache enabled as PHP module
best, Ian