Currently, tracker cache files in /tmp/cache/tracker/ are never deleted. This file stores Goals definitions, website URLs, etc. The problem is that, when goal change, the tracker cache files are deleted on the server on which the Piwik UI is running.
But the tracker cache files will not be deleted from the tracking servers if they are different servers.
I see 2 solutions to this:
Alternatively, but more complicated, we could prepare a memory / memcache layer, but this would be more complicated to setup and maintain.
In 7dfad00: Fixes #2830 Implementing Tracker Cache TTL (in config file, [Tracker]
In 2854a29: Refs #2830 More fixes forgot in previous commit
In d152c93: Fixes #2830 Implementing Tracker Cache TTL (in config file, [Tracker]
In 1cd66a2: Refs #2830 More fixes forgot in previous commit