Changes in 2.0¶
The 2.0 release of Huey is mostly API-compatible with previous versions, but there are a number of things that have been altered or improved in this release.
The serialization format for tasks has changed. An attempt has been made to provide backward compatibility when reading messages enqueued by an older version of Huey, but this is not guaranteed to work.
always_eager mode has been renamed Immediate mode. As the new name
implies, tasks are run immediately instead of being enqueued. Immediate mode is
designed to be used during testing and development. When immediate mode is
enabled, Huey switches to using in-memory storage by default, so as to avoid
accidental writes to a live storage. Immediate mode improves greatly on
always_eager mode, as it no longer requires special-casing and follows the
same code-paths used when Huey is in live mode. See Immediate mode for more
Previously, the Huey consumer accepted options to run in UTC or local-time. Various APIs, particularly around scheduling and task revocation, needed to be compatible with however the consumer was configured, and it could easily get confusing. As of 2.0, UTC-vs-localtime is specified when instantiating Huey, and all conversion happens internally, hopefully making things easier to think about – that is, you don’t have to think about it.
The events APIs have been removed and replaced by a Signals system. Signal handlers are executed synchronously by the worker(s) as they run, so it’s a bit different, but hopefully a lot easier to actually utilize, as the events API required a dedicated listener thread if you were to make any use of it (since it used a pub/sub approach). Events could be built on-top of the signals, but currently I have no plans for this.
Errors are no longer stored in a separate list. Should a task fail due to an
unhandled exception, the exception will be placed in the result store, and can
be introspected using the task’s
Huey now supports Task priority. To use priorities with Redis, you need to be
running Redis 5.0 or newer, and should use
RedisHuey continues to support older versions of Redis.
SqliteHuey and the in-memory storage used for dev/testing provide
full support for task priorities.
Changes when initializing
result_storeparameter has been renamed to
eventsparameter is removed. Events have been replaced by Signals.
store_errorsparameter is removed. Huey no longer maintains a separate list of recent errors. Unhandled errors that occur when running a task are stored in the result store. Also the
max_errorsparameter of the Redis storage engine is removed.
global_registryparameter is removed. Tasks are no longer registered to a global registry - tasks are registered to the Huey instance with which they are decorated.
always_eagerhas been renamed
New initialization arguments:
utcparameter (defaults to true). This setting is used to control how Huey interprets datetimes internally. Previously, this logic was spread across a number of APIs and a consumer flag.
- Serializer parameter accepts an (optional) object implementing the
Serializerinterface. Defaults to using
- Accepts option to use gzip
compressionwhen serializing data.
Other changes to
- Immediate mode can be enabled or disabled at runtime by setting the
- Event emitter has been replaced by Signals, so all event-related APIs have been removed.
- Special classes of exceptions for the various storage operations have been removed. For more information see Exceptions.
Huey.errors()method is gone. Errors are no longer tracked separately.
- Previously these decorators accepted two optional keyword arguments,
include_task. Since the remaining retries are stored as an attribute on the task itself, the first is redundant. In 2.0 these are replaced by a new keyword argument
context, which, if
True, will pass the task instance to the decorated function as a keyword argument.
- Enqueueing a task pipeline will now return a
ResultGroupinstead of a list of individual
Changes to the
Result handle (previous called
task_idproperty is renamed to
- Task instances that are revoked via
Result.revoke()will default to using
reschedule()method no longer requires a delay or eta. Leaving both empty will reschedule the task immediately.
- The order of arguments has been changed to match the order used on linux crontab. The order is now minute, hour, day, month, day of week.
- Huey no longer uses a global registry for task functions. Task functions are only visible to the huey instance they are decorated by.
RedisHueydefaults to using a blocking pop on the queue, which should improve latency and reduce chatter. To go back to the old polling default, specify
blocking=Falsewhen creating your huey instance.
SqliteHueyno longer has any third-party dependencies and has been moved into the main
MiniHueycontrib module has been renamed to
SimpleStoragecontrib module has been removed.
backend_classsetting has been renamed to
huey_class(used to specify import-path to Huey implementation, e.g.