Thursday, 11th March 2010
Automate EC2 Instance Setup with user-data Scripts (via) I knew about EC2’s user-data feature—what I didn’t know is that the Alestic and Canonical images are configured so that if the user-data starts with #! the instance will automatically execute it as a shell script as soon as it boots up (after networking has been configured).
Cache Machine: Automatic caching for your Django models. This is the third new ORM caching layer for Django I’ve seen in the past month! Cache Machine was developed for zamboni, the port of addons.mozilla.org to Django. Caching is enabled using a model mixin class (to hook up some post_delete hooks) and a custom caching manager. Invalidation works by maintaining a “flush list” of dependent cache entries for each object—this is currently stored in memcached and hence has potential race conditions, but a comment in the source code suggests that this could be solved by moving to redis.