I have a site on GAE that is mostly just serving a small website that has all the HTML in Memcache (but even when it's not, the site is extremely light to rerender). I get 4k to 6k hits a day.
My daily frontend instance hours hovers between 30 and 60. Also, around ten times a day, I get the following message in my logs: This request caused a new process to be started for your application, and thus caused your application code to be loaded for the first time. This request may thus take longer and use more CPU than a typical request for your application.
Does this seem right for such a simple site? I would have thought that having all the HTML in Memcache would have kept my instance hours much smaller than that, and starting new instances ten times a day seems like overkill. But I really have no idea -- there seems to be a lack of tools that actually narrow down what's causing spikes in instance hours or instances.