Hi Jeff, > I am looking to set up a mod_perl handler which keep track of the > count of requests coming in. Each child process will store this data > in local memory and after 5-10 minutes have passed, each child process > will merge its data into a central database, the goal being that each > child will not have to hit a database for every request.
I agree with the people saying that memcached/Cache::FastMmap or an in-memory file is probably fast enough to hit on every request. In general though, storing and dumping things to a db now and then is not a bad way to go for non-critical data. > The problem is --- how do i additionally have each child merge its > data on a schedule -- that is, without relying only on an incoming > request to "hit" that specific child process? You can't. The nature of apache is that it responds to network events. Cleanup handlers are also only going to fire after a request. You could rig up a cron to hit your server regularly and if the data was shared between the children then whatever child picked that up could write it to the db, but that seems a lot harder than alternatives already suggested. > Attempt #2 --- register a Clean Up hook. This doesn't seem to work for > me because, as i understand so far, assigning a reference to a sub via > PerlCleanupHandler is not the same as calling the object's method. You could just store this data in a $My::Global::Counter and read it from anywhere. Each child has its own variable storage, so this is safe. Second, you should be able to make a cleanup handler call your sub as a method > - Perhaps each child process will need to use it's own SQLite or similar > cache? SQLite may well be slower than your real database, so I wouldn't do that without testing. BTW, how are you configuring a handler to create a $self that lasts across multiple requests? - Perrin
