How can I keep on-the-fly application-level statistics in an application running under Apache?
Perhaps you could keep the relevant counters and other statistics in a memcached, that is accessed by all apache processes?
I have an application running under apache that I want to keep "in the moment" statistics on.  I want to have the application tell me things like:

requests per second, broken down by types of request
latency to make requests to various backend services via thrift (broken down by service and server)
number of errors being served per second
etc.

I want to do this without any external dependencies.  However, I'm running into issues sharing statistics between apache processes.  Obviously, I can't just use global memory.  What is a good pattern for this sort of issue?
The application is written in python using pylons, though I suspect this is more of a "communication across processes" design question than something that's python specific.