There are many different caching levels on a web server, some of them are Craft-specific, and some have nothing to do with Craft, but they often get confused. In addition to that, some of them you have control over, and some of them you get for free.
These are web server extensions installed to provide byte-level PHP caching so that PHP ...
Correct... craft()->fileCache will save to your craft/storage/runtime/cache folder by default, which will have a .bin file that has a hash of the key you provided when calling set() and the contents will be a serialized version of the value you passed in.
Also worth noting that while craft()->fileCache still exists, as of Craft 2.0, it is simply a ...
I got the same error and started debugging with XDebug.
I've put some hours in this and my conclusion is: You can't run Craft on GAE. It gets worse: You can't even run Yii1 (the framework Craft was built on) on GAE. So that's where it stops.
I did manage to get Craft running on a GAE development server instance, but to do that I had to uncomment every ...
From my comment above:
I was able to find the files uploaded to the root of my assets path and deleted them there.
Then on the control panel settings page:
Updated Asset Indexes and Cleared Cache and it seems to be all working.
There's not a native Craft way to do that.
You could setup a cron job that hit a plugin's controller and delete items in cache based on size/date created, etc.
My guess is you've got a plugin installed doing some heavy caching. You can try opening the largest cache files (it's all just serialized text data) and see if the type of data gives you a clue to ...
You should be using craft()->cache with the cacheMethod config setting set to file (which it is by default) instead of craft()->fileCache. The latter is deprecated and won't work in Craft 3.
Yii does have garbage collection on cache, and by default an item has a 0.01% change of being purged from cache regardless of expiry time.
If you think you're ...
Is it possible at all to do this through Craft?
Probably, but it kind of depends on what level of caching we're talking about and your specific use-case.
There's an overview of the different caching options available in Craft and what they mean here.