retools 0.4.1

Differences from Beaker

Unlike Beaker’s caching system, this is built strictly for Redis. As such, it adds several features that Beaker doesn’t possess:

• A distributed write-lock so that only one writer updates the cache at a time across a cluster.

• Hit/Miss cache statistics to give you insight into what caches are less effectively utilized (and may need either higher expiration times, or just not very worthwhile to cache).

• Very small, compact code-base with 100% unit test coverage.

Bug Fixes

• Call redis.expire with proper expires value for RedisLock. Patch by Mike McCabe.

• Use functools.wraps to preserve doc strings for cache_region. Patch by Daniel Holth.

API Changes

• Added get_job/get_jobs methods to QueueManager class to get information on a job or get a list of jobs for a queue.

Bug Fixes

• Critical fix for caching that prevents old values from being displayed forever. Thanks to Daniel Holth for tracking down the problem-aware.

• Actually sets the Redis expiration for a value when setting the cached value in Redis. This defaults to 1 week.

Features

• Statistics for the cache is now optional and can be disabled to slightly reduce the Redis queries used to store/retrieve cache data.

• Added first revision of worker/job Queue system, with event support.

Internals

• Heavily refactored Connection to not be a class singleton, instead a global_connection instance is created and used by default.

• Increased conditional coverage to 100% (via instrumental).

Backwards Incompatibilities

• Changing the default global Redis connection has changed semantics, instead of using Connection.set_default, you should set the global_connection’s redis property directly:

  import redis
  from retools import global_connection
  
  global_connection.redis = redis.Redis(host='myhost')

Incompatibilities

• Removed clear argument from invalidate_region, as removing keys from the set but not removing the hit statistics can lead to data accumulating in Redis that has no easy removal other than .keys() which should not be run in production environments.

• Removed deco_args from invalidate_callable (invalidate_function) as its not actually needed since the namespace is already on the callable to invalidate.