This document describes the current stable version of Kombu (5.3). For development docs, go here.

Change history



11 April, 2024


Tomer Nosrati

The release of v5.3.6 was missing the bumbversion commit so v5.3.7 is only released to sync it back.



27 Mar, 2024


Tomer Nosrati

  • boto3>=1.26.143 (#1890)

  • Always convert azureservicebus namespace to fully qualified (#1892)

  • Pin pytest-sugar to latest version 1.0.0 (#1912)

  • Upgrade to pytest v8 that removed nose compatibility (#1914)

  • fix warning for usage of utcfromtimestamp (#1926)

  • Update pytest to 8.0.2 (#1942)

  • Hotfix: Fix CI failures (limit redis to <5.0.2 instead of <6.0.0) (#1961)

  • Expose cancel callback from py-amqp channel.basic_consume (#1953)

  • Update mypy to 1.9.0 (#1963)

  • Update pytest to 8.1.1 (#1965)

  • Pin hypothesis to hypothesis<7 (#1966)

  • redis>=4.5.2,<5.0.2,!=4.5.5 -> redis>=4.5.2,!=5.0.2,!=4.5.5 (#1969)

  • add escape hatch for custom JSON serialization (#1955)

  • Pin pytest-cov to latest version 5.0.0 (#1972)



12 Jan, 2024


Tomer Nosrati

  • Fix ReadTheDocs CI (#1827).

  • fix(docs): add Redis to the list of transports where SSL is supported (#1826).

  • Fixed Improper Method Call: Replaced mktemp (#1828).

  • Bump actions/setup-python from 4 to 5 (#1829).

  • Bump github/codeql-action from 2 to 3 (#1832).

  • fix: freeze set during ticks iter in async hub (#1830).

  • azure service bus: fix TypeError when using Managed Identities (#1825).

  • Fix unacknowledge typo in restore_visible() (#1839).

  • Changed pyup -> dependabot for updating dependencies (#1842).

  • Bump pytest from 7.4.3 to 7.4.4 (#1843).

  • Bump flake8 from 6.0.0 to 7.0.0 (#1845).

  • Bump mypy from 1.3.0 to 1.8.0 (#1844).

  • Fix crash when using global_keyprefix with a sentinel connection (#1838)

  • Fixed version_dev in docs/ (#1875).



16 Nov, 2023


Asif Saif Uddin

  • Use the correct protocol for SQS requests (#1807).



6 Nov, 2023


Asif Saif Uddin

  • Raise access denied error when ack.

  • test redis 5.0.0.

  • fix azure servicebus using managed identity support (#1801).

  • Added as_uri method to MongoDB transport - Fixes #1795 (#1796).

  • Revert “[fix #1726] Use boto3 for SQS async requests (#1759)” (#1799).

  • Create a lock on cached_property if not present (#1811).

  • Bump kafka deps versions & fix integration test failures (#1818).

  • Added Python 3.12 support.

  • Fix: redis requeue concurrency bug #1800 (#1805).



31 Aug, 2023


Tomer Nosrati

  • Reverted unwanted constraint introduced in #1629 with max_retries (#1755)

  • Doc fix (hotfix for #1755) (#1758)

  • Python3.12: fix imports in kombu/utils/ (#1756)

  • [fix #1726] Use boto3 for SQS async requests (#1759)

  • docs: Remove SimpleQueue import (#1764)

  • Fixed pre-commit issues (#1773)

  • azure service bus: add managed identity support (#1641)

  • fix: Prevent redis task loss when closing connection while in poll (#1733)

  • Kombu & celery with SQS #222 (#1779)

  • syntax correction (#1780)



15 Jun, 2023


Asif Saif Uddin

  • Update pycurl version.

  • Declare python 3.11 support (#1425).

  • Fix: allow deserializing any version of UUID.

  • Update PyCurl version in SQS (#1747).



03 Jun, 2023


Asif Saif Uddin

  • Support for Kafka as transport.

  • Add fanout to filesystem (#1499).

  • Added possibility to serialize and deserialize binary messages in json (#1516).

  • Support pymongo 4.x (#1536).

  • Support redis-py 4.5.x.

  • Upgrade Azure Storage Queues transport to version 12 (#1539).

  • Add support to SQS DelaySeconds (#1567).

  • Add WATCH to prefixed complex commands.

  • Avoid losing type of UUID when serializing/deserializing (#1575).

  • Added HLEN to the list of prefixed redis commands (#1540).

  • Add managed identity support to azure storage queue (#1631).

  • Add Support of sqlalchemy v2.0.

  • Deprecate pytz and use zoneinfo (#1680)



31 May, 2023


Asif Saif Uddin

  • add missing zoneinfo dependency (#1732).

  • Support redis >= 4.5.2

  • Loosen urlib3 version range for botocore compat



24 May, 2023


Asif Saif Uddin

  • Moved to pytest-freezer (#1683).

  • Deprecate pytz and use zoneinfo (#1680).

  • handle keyerror in azureservicebus transport when message is not

found in qos and perform basic_ack (#1691). - fix mongodb transport obsolete calls (#1694). - SQS: avoid excessive GetQueueURL calls by using cached queue url (#1621). - Update confluentkafka.txt version (#1727). - Revert back to pyro4 for now.



20 Mar, 2023


Asif Saif Uddin

  • Use SPDX license expression in project metadata.

  • Allowing Connection.ensure() to retry on specific exceptions given by policy (#1629).

  • Redis==4.3.4 temporarilly in an attempt to avoid BC (#1634).

  • Add managed identity support to azure storage queue (#1631).

  • Support sqla v2.0 (#1651).

  • Switch to Pyro5 (#1655).

  • Remove unused _setupfuns from

  • Refactor: Refactor utils/json (#1659).

  • Adapt the mock to correctly mock the behaviors as implemented on Python 3.10. (Ref #1663).



19 Oct, 2022


Asif Saif Uddin

  • fix: save QueueProperties to _queue_name_cache instead of QueueClient.

  • hub: tick delay fix (#1587).

  • Fix incompatibility with redis in disconnect() (#1589).

  • Solve Kombu filesystem transport not thread safe.

  • importlib_metadata remove deprecated entry point interfaces (#1601).

  • Allow azurestoragequeues transport to be used with Azurite emulator in docker-compose (#1611).



1 Aug, 2022


Asif Saif Uddin

  • Add files to setup.cfg.

  • Add support to SQS DelaySeconds (#1567).

  • Add WATCH to prefixed complex commands.

  • Avoid losing type of UUID when serializing/deserializing (#1575).

  • chore: add confluentkafka to extras.



29 Jun, 2022


Asif Saif Uddin

  • Add fanout to filesystem (#1499).

  • Protect set of ready tasks by lock to avoid concurrent updates. (#1489).

  • Correct documentation stating kombu uses pickle protocol version 2.

  • Use new entry_points interface.

  • Add mypy to the pipeline (#1512).

  • Added possibility to serialize and deserialize binary messages in json (#1516).

  • Bump pyupgrade version and add __future__.annotations import.

  • cleaning from outdated libs (#1533).

  • bump new py-amqp to 5.1.1 (#1534).

  • add GitHub URL for PyPi.

  • Upgrade pytest to ~=7.1.1.

  • Support pymongo 4.x (#1536).

  • Initial Kafka support (#1506).

  • Upgrade Azure Storage Queues transport to version 12 (#1539).

  • move to consul2 (#1544).

  • Datetime serialization and deserialization fixed (#1515).

  • Bump redis>=4.2.2 (#1546).

  • Update sqs dependencies (#1547).

  • Added HLEN to the list of prefixed redis commands (#1540).

  • Added some type annotations.



06 Mar, 2022


Asif Saif Uddin

  • Allow getting recoverable_connection_errors without an active transport.

  • Prevent KeyError: ‘purelib’ by removing INSTALLED_SCHEME hack from

  • Revert “try pining setuptools (#1466)” (#1481).

  • Fix issue #789: Async http code not allowing for proxy config (#790).

  • Fix The incorrect times of retrying.

  • Set redelivered property for Celery with Redis (#1484).

  • Remove use of OrderedDict in various places (#1483).

  • Warn about missing hostname only when default one is available (#1488).

  • All supported versions of Python define __package__.

  • Added global_keyprefix support for pubsub clients (#1495).

  • try pytest 7 (#1497).

  • Add an option to not base64-encode SQS messages.

  • Fix SQS extract_task_name message reference.



29 Dec, 2021


Asif Saif Uddin

  • Allow redis >= 4.0.2.

  • Fix PyPy CI jobs.

  • SQS transport: detect FIFO queue properly by checking queue URL (#1450).

  • Ensure that restore is atomic in redis transport (#1444).

  • Restrict setuptools>=59.1.1,<59.7.0.

  • Bump minimum py-amqp to v5.0.9 (#1462).

  • Reduce memory usage of Transport (#1470).

  • Prevent event loop polling on closed redis transports (and causing leak).

  • Respect connection timeout (#1458)

  • prevent redis event loop stopping on ‘consumer: Cannot connect’ (#1477).



16 Nov, 2021


Asif Saif Uddin

  • Pin redis version to >= 3.4.1<4.0.0 as it is not fully compatible yet.



8 Nov, 2021


Asif Saif Uddin

  • Bump redis version to >= 3.4.1.

  • try latest sqs dependencies ti fix security warning.

  • Tests & dependency updates



5 Nov, 2021


Naomi Elstein

  • v 1.4.x (#1338).

  • stop mentioning librabbitmq (#1381).

  • Merge branch ‘master’ of

  • test new pytest version (#1383).

  • drop python 3.6 from CI (#1382).

  • Use ANY from unittest instead of case.mock.

  • Fix missing dependency to redis in docs requirements.

  • [] pre-commit autoupdate.

  • Remove dependency to case (#1389).

  • Fix: check redis response type.

  • [] pre-commit autoupdate (#1393).

  • py3.7+ on setup (#1392).

  • Prevent caching of oid in pidbox (#1394).

  • Added unittests for #1394 .

  • fix flake8 in kombu/asynchronous/aws/ (#1397).

  • [] pre-commit autoupdate.

  • Fix test_pidbox unittests to support non-linux platforms (#1398).

  • [] pre-commit autoupdate.

  • removre bdist.

  • add python 3.10 to CI & fix other issues (#1402).

  • try to fix CI (#1407).

  • Dont failfast when pypy3 tests fail (#1408).

  • Return empty list instead of InconsistencyError when exchange table is empty (#1404).

  • [] pre-commit autoupdate.



2021-09-07 7:00 P.M UTC+6:00


Asif Saif Uddin

  • Remove backward compatible code not used anymore (#1344).

  • Add support for setting redis username (#1351).

  • Add support for Python 3.9.

  • Use hostname from URI when server_host is None.

  • Use Python’s built-in json module by default, instead of simplejson.

  • SQS Channel.predefined_queues should be {} if not defined.

  • Add global key prefix for keys set by Redis transporter (#1349).

  • fix: raise BrokenPipeError (#1231).

  • fix: add missing commands to prefix.

  • Make BrokerState Transport specific.

  • Tests & Docs cleanup.



2021-05-23 7:00 P.M UTC+3:00


Omer Katz

  • Fix queue names special characters replacement for Azure Service Bus. (#1324)

  • Add support for SQLAlchemy 1.4. (#1328)

  • Coerce seconds argument to a floating point number in Timer.enter_after. (#1330)

  • Add accept parameter to SimpleQueue class. (#1140)

  • prepare_accept_content() now raises SerializerNotInstalled instead of KeyError. (#1343)



2021-04-01 10:30 P.M UTC+6:00


Asiff Saif Uddin

  • Wheels are no longer universal.

  • Revert “Added redis transport key_prefix from envvars”.

  • Redis Transport: Small improvements of SentinelChannel (#1253).

  • Fix pidbox not using default channels.

  • Revert “on worker restart - restore visible regardless to time (#905)”.

  • Add vine to dependencies.

  • Pin urllib3<1.26 to fix failing unittests.

  • Add timeout to producer publish (#1269).

  • Remove python2 compatibility code (#1277).

  • redis: Support Sentinel with SSL.

  • Support for Azure Service Bus 7.0.0 (#1284).

  • Allow specifying session token (#1283).

  • kombu/asynchronous/http/curl: implement _set_timeout.

  • Disable namedtuple to object feature in simplejson (#1297).

  • Update to tox docker 2.0.

  • SQS back-off policy (#1301).

  • Fixed SQS unittests.

  • Fix: non kombu json message decoding in SQS transport (#1306).

  • Add Github Actions CI (#1309).

  • Update default pickle protocol version to 4 (#1314).

  • Update (#1311).

  • Drop support for the lzma backport.

  • Drop obsolete code importing pickle (#1315).

  • Update default login method for librabbitmq and pyamqp (#936).

  • SQS Broker - handle STS authentication with AWS (#1322).

  • Min py-amqp version is v5.0.6 (#1325).

  • Numerous docs & example fixes.

  • Use a thread-safe implementation of cached_property (#1316).



2020-09-06 6:30 P.M UTC+3:00


Omer Katz

  • Bump required amqp version to 5.0.0.



2020-08-23 19:10 P.M UTC+3:00


Omer Katz

  • Removed kombu.five from the reference documentation since it no longer exists

  • Adjusted the stable documentation’s version in Sphinx’s configuration since that was overlooked in the latest release



2020-08-05 16:00 P.M UTC+3:00


Omer Katz

  • BREAKING CHANGE: Dropped support for Python 2 (#1232)

  • Add an SQS transport option for custom botocore config (#1219)



2020-06-24 1.15 P.M UTC+6:00


Asif Saif Uddin

  • Revert incompatible changes in #1193 and additional improvements (#1211)

  • Default_channel should reconnect automatically (#1209)



2020-06-03 10.45 A.M UTC+6:00


Asif Saif Uddin

  • Doc improvement.

  • set _connection in _ensure_connection (#1205)

  • Fix for the issue #1172

  • reuse connection [bug fix]



2020-06-01 14.00 P.M UTC+6:00


Asif Saif Uddin

  • Prevent failure if AWS creds are not explicitly defined on predefined.

  • Raise RecoverableConnectionError in maybe_declare with retry on and.

  • Fix for the issue #1172 .

  • possible fix for #1174 .

  • Fix: make SQLAlchemy Channel init thread-safe

  • Added integration testing infrastructure for RabbitMQ

  • Initial redis integration tests implementation

  • SQLAlchemy transport: Use Query.with_for_update() instead of deprecated

  • Fix Consumer Encoding

  • Added Integration tests for direct, topic and fanout exchange types

  • Added TTL integration tests

  • Added integration tests for priority queues

  • fix 100% cpu usage on linux while using sqs

  • Modified Mutex to use redis LuaLock implementation

  • Fix: eliminate remaining race conditions from SQLAlchemy Channel

  • Fix connection imaybe_declare (#1196)

  • Fix for issue #1198: Celery crashes in cases where there aren’t enough

  • Ensure connection when connecting to broker

  • update pyamqp to 2.6 with optional cythonization



2020-03-29 20:45 A.M UTC+6:00


Asif Saif Uddin

  • Added support for health_check_interval option in broker_transport_options (#1145)

  • Added retry_on_timeout parameter to Redis Channel (#1150)

  • Added support for standard values for ssl_cert_reqs query parameter for Redis (#1139)

  • Added predefined_queues option to SQS transport (#1156)

  • Added ssl certificate verification against ca certificates when amqps is used for pyamqp transport (#1151)

  • Fix issue (#701) where kombu.transport.redis.Mutex is broken in python 3 (#1141)

  • Fix brop error in Redis Channel (#1144)



2019-12-07 20:45 A.M UTC+6:00


Asif Saif Uddin

  • Use importlib.metadata from the standard library on Python 3.8+ (#1086).

  • Add peek lock settings to be changed using transport options (#1119).

  • Fix redis health checks (#1122).

  • Reset ready before execute callback (#1126).

  • Add missing parameter queue_args in kombu.connection.SimpleBuffer (#1128)



2019-11-11 00:15 A.M UTC+6:00


Asif Saif Uddin

  • Revert _lookup_direct and related changes of redis.

  • Python 3.8 support

  • Fix ‘NoneType’ object has no attribute ‘can_read’ bug of redis transport

  • Issue #1019 Fix redis transport socket timeout

  • Add wait timeout settings to receive queue message (#1110)

  • Bump py-amqp to 2.5.2



2019-09-30 19:30 P.M UTC+6:00


Asif Saif Uddin

  • Revert _lookup api and correct redis implemetnation.

  • Major overhaul of redis test cases by adding more full featured fakeredis module.

  • Add more test cases to boost coverage of kombu redis transport.

  • Refactor the producer consumer test cases to be based on original mocks and be passing

  • Fix lingering line length issue in test.

  • Sanitise url when include_password is false

  • Pinned pycurl to as it is the latest build with wheels provided

  • Bump py-amqp to 2.5.2



2019-08-14 22:45 P.M UTC+6:00


Asif Saif Uddin

  • Use importlib-metadata instead of pkg_resources for better performance

  • Allow users to switch URLs while omitting the resource identifier (#1032)

  • Don’t stop receiving tasks on 503 SQS error. (#1064)

  • Fix maybe declare (#1066)

  • Revert “Revert “Use SIMEMBERS instead of SMEMBERS to check for queue (Redis Broker)

  • Fix MongoDB backend to work properly with TTL (#1076)

  • Make sure that max_retries=0 is treated differently than None (#1080)

  • Bump py-amqp to 2.5.1



2019-06-15 12:45 A.M UTC+6:00


Asif Saif Uddin

  • Revert FastUUID for kombu 4.6



2019-06-15 12:45 A.M UTC+6:00


Asif Saif Uddin

  • Fix sbugs and regressions



2019-06-06 10:30 A.M UTC+6:00


Asif Saif Uddin

  • Fix some newly introduced bug in kombu 4.6



2019-05-30 15:30 P.M UTC+6:00


Asif Saif Uddin

  • Dropped python 3.4

  • Bump py-amqp to 2.5.0

  • Use SIMEMBERS instead of SMEMBERS to check for queue (redis broker)

    • Add _lookup_direct method to virtual channel. (#994)

    Add possibility to optimize lookup for queue in direct exchange set.

    • Add _lookup_direct method to redis virtual channel. (#994)

    Use SISMEMBER instead of SMEMBERS command to check if queue exists in a set. Time complexity is increased from O(N) to O(1) where N is the set cardinality.

    Contributed by Stevan Milic and Asif Saif Uddin

  • Include priority in properties only if it’s not None. Since we attempt to serialize the priority property if it exists in the dictionary it must be an integer.

    Contributed by Omer Katz

  • Removed dangerous default mutable arguments from function definitions where appropriate.

    Contributed by Todd Cook

  • Codebase improvements and fixes by:

    • Omer Katz

    • Asif Saif Uddin



2019-03-3 18:30 P.M UTC+3:00


Omer Katz

  • The Redis transport now supports a custom separator for keys.

    Previously when storing a key in Redis which represents a queue we used the hardcored value \x06\x16 separator to store different attributes of the queue in the queue’s name.

    The separator is now configurable using the sep transport option:

    with Connection('redis://', transport_options={
            'sep': ':',
        # ...

    Contributed by Joris Beckers

  • When the SQS server returns a timeout we ignore it and keep trying instead of raising an error.

    This will prevent Celery from raising an error and hanging.

    Contributed by Erwin Rossen

  • Properly declare async support for the Qpid transport.

    If you are using this transport we strongly urge you to upgrade.

    Contributed by Rohan McGovern

  • Revert celery/kombu#906 and introduce unique broadcast queue names as an optional keyword argument.

    If you want each broadcast queue to have a unique name specify unique=True:

    >>> from kombu.common import Broadcast
    >>> q = Broadcast(queue='foo', unique=True)
    >>> q = Broadcast(queue='foo')
  • Codebase improvements and fixes by:

    • Omer Katz



2019-03-3 9:00 P.M UTC+2:00


Omer Katz

  • Restore bz2 import checks in compression module.

    The checks were removed in celery/kombu#938 due to assumption that it only affected Jython. However, bz2 support can be missing in Pythons built without bz2 support.

    Contributed by Patrick Woods

  • Fix regression that occurred in 4.3.0 when parsing Redis Sentinel master URI containing password.

    Contributed by Peter Lithammer

  • Handle the case when only one Redis Sentinel node is provided.

    Contributed by Peter Lithammer

  • Support SSL URL parameters correctly for rediss://` URIs.

    Contributed by Paul Bailey

  • Revert celery/kombu#954. Instead bump the required redis-py dependency to 3.2.0 to include this fix andymccurdy/redis-py@4e1e748.

    Contributed by Peter Lithammer

  • Added support for broadcasting using a regular expression pattern or a glob pattern to multiple Pidboxes.

    Contributed by Jason Held



2019-01-14 7:00 P.M UTC+2:00


Omer Katz

  • Added Python 3.7 support.

    Contributed by Omer Katz, Mads Jensen and Asif Saif Uddin

  • Avoid caching queues which are declared with a TTL.

    Queues that are declared with a TTL are now also be excluded from the in-memory cache in case they expire between publishes on the same channel.

    Contributed by Matt Yule-Bennett

  • Added an index to the Message table for the SQLAlchemy transport.

    The index allows to effectively sorting the table by the message’s timestamp.


    We do not provide migrations for this model yet. You will need to add the index manually if you are already using the SQLAlchemy transport.

    The syntax may vary between databases. Please refer to your database’s documentation for instructions.

    Contributed by Mikhail Shcherbinin

  • Added a timeout that limits the amount of time we retry to reconnect to a transport.

    Contributed by :github_user:`tothegump`

  • :class:celery.asynchronous.hub.Hub is now reentrant.

    This allows calling celery.bin.celery.main() to revive a worker in the same process after rescuing from shutdown (:class:SystemExit).

    Contributed by Alan Justino da Silva

  • Queues now accept string exchange names as arguments as documented.

    Tests were added to avoid further regressions.

    Contributed by Antonio Gutierrez

  • Specifying names for broadcast queues now work as expected.

    Previously, named broadcast queues did not create multiple queues per worker. They incorrectly declared the named queue which resulted in one queue per fanout exchange, thus missing the entire point of a fanout exchange. The behavior is now matched to unnamed broadcast queues.

    Contributed by Kuan Hsuan-Tso

  • When initializing the Redis transport in conjunction with gevent restore all unacknowledged messages to queue.

    Contributed by Gal Cohen

  • Allow :class:kombu.simple.SimpleQueue to pass queue_arguments to Queue object.

    This allows :class:kombu.simple.SimpleQueue to connect to RabbitMQ queues with custom arguments like ‘x-queue-mode’=’lazy’.

    Contributed by C Blue Neeh

  • Add support for ‘rediss’ scheme for secure Redis connections.

    The rediss scheme defaults to the least secure form, as there is no suitable default location for ca_certs. The recommendation would still be to follow the documentation and specify broker_use_ssl if coming from celery.

    Contributed by Daniel Blair

  • Added the Azure Storage Queues transport.

    The transport is implemented on top of Azure Storage Queues. This offers a simple but scalable and low-cost PaaS transport for Celery users in Azure. The transport is intended to be used in conjunction with the Azure Block Blob Storage backend.

    Contributed by Clemens Wolff, :github_user:`@ankurokok`, Denis Kisselev, Evandro de Paula, Martin Peck and :github_user:`@michaelperel`

  • Added the Azure Service Bus transport.

    The transport is implemented on top of Azure Service Bus and offers PaaS support for more demanding Celery workloads in Azure. The transport is intended to be used in conjunction with the Azure CosmosDB backend.

    Contributed by Clemens Wolff, :github_user:`@ankurokok`, Denis Kisselev, Evandro de Paula, Martin Peck and :github_user:`@michaelperel`

  • Drop remaining mentions of Jython support completely.

    Contributed by Asif Saif Uddin and Mads Jensen

  • When publishing messages to the Pidbox, retry if an error occurs.

    Contributed by Asif Saif Uddin

  • Fix infinite loop in :method:kombu.asynchronous.hub.Hub.create_loop.

    Previous attempt to fix the problem (PR kombu/760) did not consider an edge case. It is now fixed.

    Contributed by Vsevolod Strukchinsky

  • Worker shutdown no longer duplicates messages when using the SQS broker.

    Contributed by Mintu Kumar Sah

  • When using the SQS broker, prefer boto’s default region before our hardcoded default.

    Contributed by Victor Villas

  • Fixed closing of shared redis sockets which previously caused Celery to hang.

    Contributed by Alexey Popravka

  • the Pyro transport (kombu.transport.pyro) now works with recent Pyro versions. Also added a Pyro Kombu Broker that this transport needs for its queues.

    Contributed by Irmen de Jong

  • Handle non-base64-encoded SQS messages.

    Fix contributed by Tim Li, Asif Saif Uddin and Omer Katz.

  • Move the handling of Sentinel failures to the redis library itself.

    Previously, Redis Sentinel worked only if the first node’s sentinel service in the URI was up. A server outage would have caused downtime.

    Contributed by Brian Price

  • When using Celery and the pickle serializer with binary data as part of the payload, UnicodeDecodeError would be raised as the content was not utf-8. We now replace on errors.

    Contributed by Jian Dai

  • Allow setting :method:boto3.sqs.create_queue Attributes via transport_options.

    Contributed by Hunter Fernandes

  • Fixed infinite loop when is replaced by revive() on connection drop.

    Contributed by Tzach Yarimi

  • Added optional support for Brotli compression.

    Contributed by Omer Katz

  • When using the SQS broker, FIFO queues with names that ended with the ‘f’ letter were incorrectly parsed. This is now fixed.

    Contributed by Alex Vishnya and Ilya Konstantinov

  • Added optional support for LZMA compression.

Contributed by Omer Katz

  • Added optional support for ZStandard compression.

    Contributed by Omer Katz

  • Require py-amqp 2.4.0 as the minimum version.

    Contributed by Asif Saif Uddin

  • The value of DISABLE_TRACEBACKS environment variable is now respected on debug, info and warning logger level.

    Contributed by Ludovic Rivallain

  • As documented in kombu/#741 and eventlet/eventlet#415 there is a mismatch between the monkey-patched eventlet queue and the interface Kombu is expecting. This causes Celery to crash when the broker_pool_limit configuration option is set eventlet/eventlet#415 suggests that the mutex can be a noop. This is now the case.

    Contributed by Josh Morrow

  • Codebase improvements and fixes by:

    • Omer Katz

    • Mads Jensen

    • Asif Saif Uddin

    • Lars Rinn

  • Documentation improvements by:

    • Jon Dufresne

    • Fay Cheng

    • Asif Saif Uddin

    • Kyle Verhoog

    • Noah Hall

    • :github_user:`brabiega`



2019-01-01 04:00 P.M IST


Omer Katz


The previous release contained code from master. It is now deleted from PyPi. Please use this release instead.

  • No changes since previous release.



2018-12-06 04:30 P.M IST


Omer Katz

  • Support both Redis client version 2.x and version 3.x.

    Contributed by Ash Berlin-Taylor and Jeppe Fihl-Pearson



2018-05-21 09:00 A.M IST


Omer Katz


The 4.2.0 release contained remains of the async module by accident. This is now fixed.

  • Handle librabbitmq fileno raising a ValueError when socket is not connected.

    Contributed by Bryan Shelton



2018-05-21 09:00 A.M IST


Omer Katz

  • Now passing max_retries, interval_start, interval_step, interval_max parameters from broker transport_options to ensure_connection() when returning default_connection() (Issue #765).

    Contributed by Anthony Lukach.

  • Qpid: messages are now durable by default

    Contributed by David Davis

  • Kombu now requires version 2.10.4 or greater of the redis library, in line with Celery

    Contributed by Colin Jeanne

  • Fixed ImportError in some environments with outdated simplejson

    Contributed by Aaron Morris

  • MongoDB: fixed failure on MongoDB versions with an “-rc” tag

    Contributed by dust8

  • Ensure periodic polling frequency does not exceed timeout in virtual transport

    Contributed by Arcadiy Ivanov

  • Fixed string handling when using python-future module

    Contributed by John Koehl

  • Replaced “async” with “asynchronous” in preparation for Python 3.7

    Contributed by Thomas Achtemichuk

  • Allow removing pool size limit when in use

    Contributed by Alex Hill

  • Codebase improvements and fixes by:

    • j2gg0s

    • Jon Dufresne

    • Jonas Lergell

    • Mads Jensen

    • Nicolas Delaby

    • Omer Katz

  • Documentation improvements by:

    • Felix Yan

    • Harry Moreno

    • Mads Jensen

    • Omer Katz

    • Radha Krishna. S.

    • Wojciech Matyśkiewicz



2017-07-17 04:45 P.M MST


Anthony Lukach

  • SQS: Added support for long-polling on all supported queries. Fixed bug causing error on parsing responses with no retrieved messages from SQS.

    Contributed by Anthony Lukach.

  • Async hub: Fixed potential infinite loop while performing todo tasks (Issue celery/celery#3712).

  • Qpid: Fixed bug where messages could have duplicate delivery_tag (Issue #563).

    Contributed by bmbouter.

  • MongoDB: Fixed problem with using readPreference option at pymongo 3.x.

    Contributed by Mikhail Elovskikh.

  • Re-added support for :pypi:SQLAlchemy

    Contributed by Amin Ghadersohi.

  • SQS: Fixed bug where hostname would default to localhost if not specified in settings.

    Contributed by Anthony Lukach.

  • Redis: Added support for reading password from transport URL (Issue #677).

    Contributed by George Psarakis.

  • RabbitMQ: Ensured safer encoding of queue arguments.

    Contributed by Robert Kopaczewski.

  • Added fallback to :func:uuid.uuid5 in :func:generate_oid if :func:uuid.uuid3 fails.

    Contributed by Bill Nottingham.

  • Fixed race condition and innacurrate timeouts for :class:kombu.simple.SimpleBase (Issue #720).

    Contributed by c-nichols.

  • Zookeeper: Fixed last chroot character trimming

    Contributed by Dima Kurguzov.

  • RabbitMQ: Fixed bug causing an exception when attempting to close an already-closed connection (Issue #690).

    Contributed by eavictor.

  • Removed deprecated use of StopIteration in generators and invalid regex escape sequence.

    Contributed by Jon Dufresne.

  • Added Python 3.6 to CI testing.

    Contributed by Jon Dufresne.

  • SQS: Allowed endpoint URL to be specified in the boto3 connection.

    Contributed by georgepsarakis.

  • SQS: Added support for Python 3.4.

    Contributed by Anthony Lukach.

  • SQS: kombu[sqs] now depends on (no longer using

    • Adds support for Python 3.4+

    • Adds support for FIFO queues (Issue #678) and (Issue celery/celery#3690)

    • Avoids issues around a broken endpoints file (Issue celery/celery#3672)

    Contributed by Mischa Spiegelmock and Jerry Seutter.

  • Zookeeper: Added support for delaying task with Python 3.

    Contributed by Dima Kurguzov.

  • SQS: Fixed bug where kombu.transport.SQS.drain_events() did not support callback argument (Issue #694).

    Contributed by Michael Montgomery.

  • Fixed bug around modifying dictionary size while iterating over it (Issue #675).

    Contributed by Felix Yan.

  • etcd: Added handling for EtcdException exception rather than EtcdError.

    Contributed by Stephen Milner.

  • Documentation improvements by:

    • Mads Jensen

    • Matias Insaurralde

    • Omer Katz

    • Dmitry Dygalo

    • Christopher Hoskin



2016-12-15 03:31 P.M PST


Ask Solem

  • Now depends on amqp 2.1.4

    This new version takes advantage of TCP Keepalive settings on Linux, making it better at detecting closed connections, also in failover conditions.

  • Redis: Priority was reversed so, e.g. priority 0 became priority 9.



2016-12-07 06:00 P.M PST


Ask Solem

  • Now depends on amqp 2.1.3

    This new version takes advantage of the new TCP_USER_TIMEOUT socket option on Linux.

  • Producer: Fixed performance degradation when default exchange specified (Issue #651).

  • QPid: Switch to using getattr in qpid.Transport.__del__ (Issue #658)

    Contributed by Patrick Creech.

  • QPid: Now uses monotonic time for timeouts.

  • MongoDB: Fixed compatibility with Python 3 (Issue #661).

  • Consumer: __exit__ now skips cancelling consumer if connection-related error raised (Issue #670).

  • MongoDB: Removes use of natural sort (Issue #638).

    Contributed by Anton Chaporgin.

  • Fixed wrong keyword argument channel error (Issue #652).

    Contributed by Toomore Chiang.

  • Safe argument to urllib.quote must be bytes on Python 2.x (Issue #645).

  • Documentation improvements by:

    • Carlos Edo

    • Cemre Mengu



2016-10-28 16:45 P.M UTC


Ask Solem

  • Now depends on amqp 2.0.

    The new py-amqp version have been refactored for better performance, using modern Python socket conventions, and API consistency.

  • No longer depends on anyjson.

    Kombu will now only choose between and the built-in json.

    Using the latest version of simplejson is recommended:

    $ pip install -U simplejson
  • Removed transports that are no longer supported in this version:

    • Django ORM transport

    • SQLAlchemy ORM transport

    • Beanstalk transport

    • ZeroMQ transport

    • amqplib transport (use pyamqp).

  • API Changes

    • Signature of kombu.Message now takes body as first argment.

      It used to be Message(channel, body=body, **kw), but now it’s Message(body, channel=channel, **kw).

      This is unlikey to affect you, as the Kombu API does not have users instantiate messages manually.

  • New SQS transport

    Donated by NextDoor, with additional contributions from mdk.


    kombu[sqs] now depends on

  • New Consul transport.

    Contributed by Wido den Hollander.

  • New etcd transport.

    Contributed by Stephen Milner.

  • New Qpid transport.

    It was introduced as an experimental transport in Kombu 3.0, but is now mature enough to be fully supported.

    Created and maintained by Brian Bouterse.

  • Redis: Priority 0 is now lowest, 9 is highest. (backward incompatible)

    This to match how priorities in AMQP works.

    Fix contributed by Alex Koshelev.

  • Redis: Support for Sentinel

    You can point the connection to a list of sentinel URLs like:


    where each sentinel is separated by a ;. Multiple sentinels are handled by kombu.Connection constructor, and placed in the alternative list of servers to connect to in case of connection failure.

    Contributed by Sergey Azovskov, and Lorenzo Mancini

  • RabbitMQ Queue Extensions

    New arguments have been added to kombu.Queue that lets you directly and conveniently configure the RabbitMQ queue extensions.

  • RabbitMQ: Message.ack now supports the multiple argument.

    If multiple is set to True, then all messages received before the message being acked will also be acknowledged.

  • amqps:// can now be specified to require SSL (Issue #610).

  • Consumer.cancel_by_queue is now constant time.

  • Connection.ensure* now raises kombu.exceptions.OperationalError.

    Things that can be retried are now reraised as kombu.exceptions.OperationalError.

  • Redis: Fixed SSL support.

    Contributed by Robert Kolba.

  • New Queue.consumer_arguments can be used for the ability to set consumer priority via x-priority.



        consumer_arguments={'x-priority': 3},
  • Queue/Exchange: no_declare option added (also enabled for internal amq. exchanges) (Issue #565).

  • JSON serializer now calls obj.__json__ for unsupported types.

    This means you can now define a __json__ method for custom types that can be reduced down to a built-in json type.


    class Person:
        first_name = None
        last_name = None
        address = None
        def __json__(self):
            return {
                'first_name': self.first_name,
                'last_name': self.last_name,
                'address': self.address,
  • JSON serializer now handles datetimes, Django promise, UUID and Decimal.

  • Beanstalk: Priority 0 is now lowest, 9 is highest. (backward incompatible)

    This to match how priorities in AMQP works.

    Fix contributed by Alex Koshelev.

  • Redis: now supports SSL using the ssl argument to Connection.

  • Redis: Fanout exchanges are no longer visible between vhosts, and fanout messages can be filtered by patterns. (backward incompatible)

    It was possible to enable this mode previously using the fanout_prefix, and fanout_patterns transport options, but now these are enabled by default.

    If you want to mix and match producers/consumers running different versions you need to configure your kombu 3.x clients to also enable these options:

    >>> Connection(transport_options={
        'fanout_prefix': True,
        'fanout_patterns': True,
  • Pidbox: Mailbox new arguments: TTL and expiry.

    Mailbox now supports new arguments for controlling message TTLs and queue expiry, both for the mailbox queue and for reply queues.

    • queue_expires (float/int seconds).

    • queue_ttl (float/int seconds).

    • reply_queue_expires (float/int seconds).

    • reply_queue_ttl (float/int seconds).

    All take seconds in int/float.

    Contributed by Alan Justino.

  • Exchange.delivery_mode now defaults to None, and the default is instead set by Producer.publish.

  • Consumer now supports a new prefetch_count argument, which if provided will force the consumer to set an initial prefetch count just before starting.

  • Virtual transports now stores priority as a property, not in delivery_info, to be compatible with AMQP.

  • reply_to argument to Producer.publish can now be Queue instance.

  • Connection: There’s now a new method Connection.supports_exchange_type(type) that can be used to check if the current transport supports a specific exchange type.

  • SQS: Consumers can now read json messages not sent by Kombu.

    Contributed by Juan Carlos Ferrer.

  • SQS: Will now log the access key used when authentication fails.

    Contributed by Hank John.

  • Added new kombu.mixins.ConsumerProducerMixin for consumers that will also publish messages on a separate connection.

  • Messages: Now have a more descriptive repr.

    Contributed by Joshua Harlow.

  • Async: HTTP client based on curl.

  • Async: Now uses poll instead of select where available.

  • MongoDB: Now supports priorities

    Contributed by Alex Koshelev.

  • Virtual transports now supports multiple queue bindings.

    Contributed by Federico Ficarelli.

  • Virtual transports now supports the anon exchange.

    If when publishing a message, the exchange argument is set to ‘’ (empty string), the routing_key will be regarded as the destination queue.

    This will bypass the routing table compeltely, and just deliver the message to the queue name specified in the routing key.

  • Zookeeper: Transport now uses the built-in suport in kazoo to handle failover when using a list of server names.

    Contributed by Joshua Harlow.

  • now passes keyword arguments to .consume.

Deprecations and removals

  • The deprecated method Consumer.add_queue_from_dict has been removed.

    Use instead:

    consumer.add_queue(Queue.from_dict(queue_name, **options))
  • The deprecated function kombu.serialization.encode has been removed.

  • The deprecated function kombu.serialization.decode has been removed.

  • Removed module kombu.syn

    detect_environment has been moved to kombu.utils.compat



2016-10-06 05:00 P.M PDT


Ask Solem

  • Connection: Return value of .info() was no longer JSON serializable, leading to “itertools.cycle object not JSON serializable” errors (Issue #635).



2016-09-30 03:06 P.M PDT


Ask Solem

  • Connection: Fixed bug when cloning connection with alternate urls.

    Fix contributed by Emmanuel Cazenave.

  • Redis: Fixed problem with unix socket connections.

    Fix contributed by Raphael Michel.

  • Redis: Fixed compatibility with older redis-py versions (Issue #576).

  • Broadcast now retains queue name when being copied/pickled (Issue #578).



2016-03-22 11:22 P.M PST


Ask Solem

  • msgpack: msgpack support now requires msgpack-python > 0.4.7.

  • Redis: TimeoutError was no longer handled as a recoverable error.

  • Redis: Adds the ability to set more Redis connection options using Connection(transport_options={...}).

    • socket_connect_timeout

    • socket_keepalive (requires redis-py > 2.10)

    • socket_keepalive_options (requires redis-py > 2.10)

  • msgpack: Fixes support for binary/unicode data



2016-03-03 05:30 P.M PST


Ask Solem

  • Qpid: Adds async error handling.

    Contributed by Brian Bouterse.

  • Qpid: Delivery tag is now a UUID4 (Issue #563).

    Fix contributed by Brian Bouterse.

  • Redis: Connection.as_uri() returned malformed URLs when the redis+socket scheme was ised (Issue celery/celery#2995).

  • msgpack: Use binary encoding instead of utf-8 (Issue #570).



2016-01-08 06:36 P.M PST


Ask Solem

  • Now depends on amqp 1.4.9.

  • Redis: Fixed problem with auxilliary connections causing the main consumer connection to be closed (Issue #550).

  • Qpid: No longer uses threads to operate, to ensure compatibility with all environments (Issue #531).



2015-12-16 02:29 P.M PST


Ask Solem

  • Redis: Fixed bug introduced in 3.0.31 where the redis transport always connects to localhost, regardless of host setting.



2015-12-16 12:00 P.M PST


Ask Solem

  • Redis: Fixed bug introduced in 3.0.30 where socket was prematurely disconnected.

  • Hub: Removed debug logging message: “Deregistered fd…” (Issue #549).



2015-12-07 12:28 A.M PST


Ask Solem

  • Fixes compatiblity with uuid in Python 2.7.11 and 3.5.1.

    Fix contributed by Kai Groner.

  • Redis transport: Attempt at fixing problem with hanging consumer after disconnected from server.

  • Event loop:

    Attempt at fixing issue with 100% CPU when using the Redis transport,

  • Database transport: Fixed oracle compatiblity.

    An “ORA-00907: missing right parenthesis” error could manifest when using an Oracle database with the database transport.

    Fix contributed by Deepak N.

  • Documentation fixes

    Contributed by Tommaso Barbugli.



2015-10-26 11:10 A.M PDT


Ask Solem

  • Fixed serialization issue for bindings.as_dict() (Issue #453).

    Fix contributed by Sergey Tikhonov.

  • Json serializer wrongly treated bytes as ascii, not utf-8 (Issue #532).

  • MongoDB: Now supports pymongo 3.x.

    Contributed by Len Buckens.

  • SQS: Tests passing on Python 3.

    Fix contributed by Felix Yan



2015-10-12 12:00 PM PDT


Ask Solem

Django transport migrations.

If you’re using Django 1.8 and have already created the kombu_transport_django tables, you have to run a fake initial migration:

$ python migrate kombu_transport_django --fake-initial
  • No longer compatible with South by default.

    To keep using kombu.transport.django with South migrations you now need to configure a new location for the kombu migrations:

  • Keep old South migrations in kombu.transport.django.south_migrations.

  • Now works with Redis < 2.10 again.



2015-10-09 3:10 PM PDT


Ask Solem

  • Now depends on amqp 1.4.7.

  • Fixed libSystem import error on some macOS 10.11 (El Capitan) installations.

    Fix contributed by Eric Wang.

  • Now compatible with Django 1.9.

  • Django: Adds migrations for the database transport.

  • Redis: Now depends on py-redis 2.10.0 or later (Issue #468).

  • QPid: Can now connect as localhost (Issue #519).

    Fix contributed by Brian Bouterse.

  • QPid: Adds support for login_method (Issue #502, Issue #499).

    Contributed by Brian Bouterse.

  • QPid: Now reads SASL mechanism from broker string (Issue #498).

    Fix contributed by Brian Bouterse.

  • QPid: Monitor thread now properly terminated on session close (Issue #485).

    Fix contributed by Brian Bouterse.

  • QPid: Fixed file descriptor leak (Issue #476).

    Fix contributed by Jeff Ortel

  • Docs: Fixed wrong order for entrypoint arguments (Issue #473).

  • ConsumerMixin: Connection error logs now include traceback (Issue #480).

  • BaseTransport now raises RecoverableConnectionError when disconnected (Issue #507).

  • Consumer: Adds tag_prefix option to modify how consumer tags are generated (Issue #509).



2015-04-22 06:00 P.M UTC


Ask Solem

  • Fixed compatibility with py-redis versions before 2.10.3 (Issue #470).



2015-04-21 02:00 P.M UTC


Ask Solem

  • pyamqp/librabbitmq now uses 5671 as default port when SSL is enabled (Issue #459).

  • Redis: Now supports passwords in redis+socket://:pass@host:port URLs (Issue #460).

  • Producer.publish now defines the expiration property in support of the RabbitMQ per-message TTL extension.

    Contributed by Anastasis Andronidis.

  • Connection transport attribute now set correctly for all transports.

    Contributed by Alex Koshelev.

  • qpid: Fixed bug where the connectionw as not being closed properly.

    Contributed by Brian Bouterse.

  • bindings is now JSON serializable (Issue #453).

    Contributed by Sergey Tikhonov.

  • Fixed typo in error when yaml is not installed (said msgpack).

    Contributed by Joshua Harlow.

  • Redis: Now properly handles redis.exceptions.TimeoutError raised by redis.

    Contributed by markow.

  • qpid: Adds additional string to check for when connecting to qpid.

    When we connect to qpid, we need to ensure that we skip to the next SASL mechanism if the current mechanism fails. Otherwise, we will keep retrying the connection with a non-working mech.

    Contributed by Chris Duryee.

  • qpid: Handle NotFound exceptions.

    Contributed by Brian Bouterse.

  • Queue.__repr__ now makes sure return value is not unicode (Issue #440).

  • qpid: Queue.purge incorrectly raised AttributeErrror if the does not exist (Issue #439).

    Contributed by Brian Bouterse.

  • Linux: Now ignores permission errors on epoll unregister.



2014-11-17 11:00 P.M UTC


Ask Solem

  • The Qpid broker is supported for Python 2.x environments. The Qpid transport includes full SSL support within Kombu. See the kombu.transport.qpid docs for more info.

    Contributed by Brian Bouterse and Chris Duryee through support from Red Hat.

  • Dependencies: extra[librabbitmq] now requires librabbitmq 1.6.0

  • Docstrings for TokenBucket did not match implementation.

    Fix contributed by Jesse Dhillon.

  • oid_from() accidentally called uuid.getnode() but did not use the return value.

    Fix contributed by Alexander Todorov.

  • Redis: Now ignores errors when cosing the underlying connection.

  • Redis: Restoring messages will now use a single connection.

  • kombu.five.monotonic: Can now be imported even if ctypes is not available for some reason (e.g. App Engine)

  • Documentation: Improved example to use the declare argument to Producer (Issue #423).

  • Django: Fixed app_label for older Django versions (< 1.7). (Issue #414).



2014-09-14 10:45 P.M UTC


Ask Solem

  • Django: Fixed bug in the Django 1.7 compatibility improvements related to autocommit handling.

    Contributed by Radek Czajka.

  • Django: The Django transport models would not be created on syncdb after app label rename (Issue #406).



2014-09-04 03:00 P.M UTC


Ask Solem

  • kombu.async: Min. delay between waiting for timer was always increased to one second.

  • Fixed bug in itermessages where message is received after the with statement exits the block.

    Fixed by Rumyana Neykova

  • Connection.autoretry: Now works with functions missing wrapped attributes

    (__module__, __name__, __doc__). Fixes #392.

    Contributed by johtso.

  • Django: Now sets custom app label for kombu.transport.django to work with recent changes in Django 1.7.

  • SimpleQueue removed messages from the wrong end of buffer (Issue #380).

  • Tests: Now using unittest.mock if available (Issue #381).



2014-07-07 02:00 P.M UTC


Ask Solem

  • Fixed remaining bug in maybe_declare for auto_delete exchanges.

    Fix contributed by Roger Hu.

  • MongoDB: Creating a channel now properly evaluates a connection (Issue #363).

    Fix contributed by Len Buckens.



2014-06-24 02:30 P.M UTC


Ask Solem

  • Reverts change in 3.0.17 where maybe_declare caches the declaration of auto_delete queues and exchanges.

    Fix contributed by Roger Hu.

  • Redis: Fixed race condition when using gevent and the channel is closed.

    Fix contributed by Andrew Rodionoff.



2014-06-09 03:10 P.M UTC


Ask Solem

  • The wheel distribution did not support Python 2.6 by failing to list the extra dependencies required.

  • Durable and auto_delete queues/exchanges can be be cached using maybe_declare.



2014-06-02 06:00 P.M UTC


Ask Solem

  • A typo introduced in 3.0.17 caused kombu.async.hub to crash (Issue #360).



2014-06-02 05:00 P.M UTC


Ask Solem

  • kombu[librabbitmq] now depends on librabbitmq 1.5.2.

  • Async: Event loop now selectively removes file descriptors for the mode it failed in, and keeps others (e.g read vs write).

    Fix contributed by Roger Hu.

  • CouchDB: Now works without userid set.

    Fix contributed by Latitia M. Haskins.

  • SQLAlchemy: Now supports recovery from connection errors.

    Contributed by Felix Schwarz.

  • Redis: Restore at shutdown now works when ack emulation is disabled.

  • kombu.common.eventloop() accidentally swallowed socket errors.

  • Adds kombu.utils.url.sanitize_url()



2014-05-06 01:00 P.M UTC


Ask Solem

  • kombu[librabbitmq] now depends on librabbitmq 1.5.1.

  • Redis: Fixes TypeError problem in unregister (Issue #342).

    Fix contributed by Tobias Schottdorf.

  • Tests: Some unit tests accidentally required the redis-py library.

    Fix contributed by Randy Barlow.

  • librabbitmq: Would crash when using an older version of librabbitmq, now emits warning instead.



2014-04-15 09:00 P.M UTC


Ask Solem

  • Now depends on amqp 1.4.5.

  • RabbitMQ 3.3 changes QoS semantics (Issue #339).

    See the RabbitMQ release notes here:

    A new connection property has been added that can be used to detect whether the remote server is using this new QoS behavior:

    >>> Connection('amqp://').qos_behavior_matches_spec

    so if your application depends on the old semantics you can use this to set the apply_global flag appropriately:

    def update_prefetch_count(channel, new_value):
            0, new_value,
            not channel.connection.client.qos_behavior_matches_spec,
  • Users of librabbitmq is encouraged to upgrade to librabbitmq 1.5.0.

    The kombu[librabbitmq] extra has been updated to depend on this version.

  • Pools: Now takes transport options into account when comparing connections (Issue #333).

  • MongoDB: Fixes Python 3 compatibility.

  • Async: select: Ignore socket errors when attempting to unregister handles from the loop.

  • Pidbox: Can now be configured to use a serializer other than json, but specifying a serializer argument to Mailbox.

    Contributed by Dmitry Malinovsky.

  • Message decompression now works with Python 3.

    Fix contributed by Adam Gaca.



2014-03-19 07:00 P.M UTC


Ask Solem

  • MongoDB: Now endures a connection failover (Issue #123).

    Fix contributed by Alex Koshelev.

  • MongoDB: Fixed KeyError when a replica set member is removed.

    Also fixes celery#971 and celery/#898.

    Fix contributed by Alex Koshelev.

  • MongoDB: Fixed MongoDB broadcast cursor re-initialization bug.

    Fix contributed by Alex Koshelev.

  • Async: Fixed bug in lax semaphore implementation where in some usage patterns the limit was not honored correctly.

    Fix contributed by Ionel Cristian Mărieș.

  • Redis: Fixed problem with fanout when using Python 3 (Issue #324).

  • Redis: Fixed AttributeError from attempting to close a non-existing connection (Issue #320).



2014-03-03 04:00 P.M UTC


Ask Solem

  • Redis: Fixed serious race condition that could lead to data loss.

    The delivery tags were accidentally set to be an incremental number local to the channel, but the delivery tags need to be globally unique so that a message can not overwrite an older message in the backup store.

    This change is not backwards incompatible and you are encouraged to update all your system using a previous version as soon as possible.

  • Now depends on amqp 1.4.4.

  • Pidbox: Now makes sure message encoding errors are handled by default, so that a custom error handler does not need to be specified.

  • Redis: The fanout exchange can now use AMQP patterns to route and filter messages.

    This change is backwards incompatible and must be enabled with the fanout_patterns transport option:

    >>> conn = kombu.Connection('redis://', transport_options={
    ...     'fanout_patterns': True,
    ... })

    When enabled the exchange will work like an amqp topic exchange if the binding key is a pattern.

    This is planned to be default behavior in the future.

  • Redis: Fixed cycle no such attribute error.



2014-02-09 03:50 P.M UTC


Ask Solem

  • Now depends on amqp 1.4.3.

  • Fixes Python 3.4 logging incompatibility (Issue #311).

  • Redis: Now properly handles unknown pub/sub messages.

    Fix contributed by Sam Stavinoha.

  • amqplib: Fixed bug where more bytes were requested from the socket than necessary.

    Fix contributed by Ionel Cristian Mărieș.



2014-02-03 05:00 P.M UTC


Ask Solem

  • Now depends on amqp 1.4.2.

  • Now always trusts messages of type application/data and application/text or which have an unspecified content type (Issue #306).

  • Compression errors are now handled as decode errors and will trigger the Consumer.on_decode_error callback if specified.

  • New kombu.Connection.get_heartbeat_interval() method that can be used to access the negotiated heartbeat value.

  • kombu.common.oid_for no longer uses the MAC address of the host, but

    instead uses a process-wide UUID4 as a node id.

    This avoids a call to uuid.getnode() at module scope.

  • Hub.add: Now normalizes registered fileno.

    Contributed by Ionel Cristian Mărieș.

  • SQS: Fixed bug where the prefetch count limit was not respected.



2014-01-17 05:40 P.M UTC


Ask Solem

  • Now depends on amqp 1.4.1.

  • maybe_declare now raises a “recoverable connection error” if the channel is disconnected instead of a ChannelError so that the operation can be retried.

  • Redis: Consumer.cancel() is now thread safe.

    This fixes an issue when using gevent/eventlet and a message is handled after the consumer is canceled resulting in a “message for queue without consumers” error.

  • Retry operations would not always respect the interval_start value when calculating the time to sleep for (Issue #303).

    Fix contributed by Antoine Legrand.

  • Timer: Fixed “unhashable type” error on Python 3.

  • Hub: Do not attempt to unregister operations on an already closed poller instance.



2014-01-13 05:30 P.M UTC


Ask Solem

  • Now depends on amqp 1.4.0.

  • Redis: Basic cancel for fanout based queues now sends a corresponding UNSUBSCRIBE command to the server.

    This fixes an issue with pidbox where reply messages could be received after the consumer was canceled, giving the "message to queue without consumers" error.

  • MongoDB: Improved connection string and options handling (Issue #266 + Issue #120).

    Contributed by Alex Koshelev.

  • SQS: Limit the number of messages when receiving in batch to 10.

    This is a hard limit enforced by Amazon so the sqs transport must not exceeed this value.

    Fix contributed by Eric Reynolds.

  • ConsumerMixin: consume now checks heartbeat every time the socket times out.

    Contributed by Dustin J. Mitchell.

  • Retry Policy: A max retries of 0 did not retry forever.

    Fix contributed by Antoine Legrand.

  • Simple: If passing a Queue object the simple utils will now take default routing key from that queue.

    Contributed by Fernando Jorge Mota.

  • repr(producer) no longer evaluates the underlying channnel.

  • Redis: The map of Redis error classes are now exposed at the module level using the kombu.transport.redis.get_redis_error_classes() function.

  • Async: Hub.close now sets .poller to None.



2013-12-16 05:00 P.M UTC


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  • Serializer: loads and dumps now wraps exceptions raised into DecodeError and kombu.exceptions.EncodeError respectively.

    Contributed by Ionel Cristian Maries

  • Redis: Would attempt to read from the wrong connection if a select/epoll/kqueue exception event happened.

    Fix contributed by Michael Nelson.

  • Redis: Disabling ack emulation now works properly.

    Fix contributed by Michael Nelson.

  • Redis: IOError and OSError are now treated as recoverable connection errors.

  • SQS: Improved performance by reading messages in bulk.

    Contributed by Matt Wise.

  • Connection Pool: Attempting to acquire from a closed pool will now raise RuntimeError.



2013-12-02 04:00 P.M UTC


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  • Fixes Python 2.6 compatibility.

  • Redis: Fixes ‘bad file descriptor’ issue.



2013-11-21 04:50 P.M UTC


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  • Timer: No longer attempts to hash keyword arguments (Issue #275).

  • Async: Did not account for the long type for file descriptors.

    Fix contributed by Fabrice Rabaute.

  • PyPy: kqueue support was broken.

  • Redis: Bad pub/sub payloads no longer crashes the consumer.

  • Redis: Unix socket URLs can now specify a virtual host by including it as a query parameter.

    Example URL specifying a virtual host using database number 3:

  • kombu.VERSION is now a named tuple.



2013-11-15 11:00 P.M UTC


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  • Now depends on amqp 1.3.3.

  • Redis: Fixed Python 3 compatibility problem (Issue #270).

  • MongoDB: Fixed problem with URL parsing when authentication used.

    Fix contributed by dongweiming.

  • pyamqp: Fixed small issue when publishing the message and the property dictionary was set to None.

    Fix contributed by Victor Garcia.

  • Fixed problem in repr(LaxBoundedSemaphore).

    Fix contributed by Antoine Legrand.

  • Tests now passing on Python 3.3.



2013-11-08 01:00 P.M UTC


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  • common.QoS: decrement_eventually now makes sure the value does not go below 1 if a prefetch count is enabled.



2013-11-04 03:00 P.M UTC


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  • SQS: Properly reverted patch that caused delays between messages.

    Contributed by James Saryerwinnie

  • select: Clear all registerd fds on poller.cloe

  • Eventloop: unregister if EBADF raised.



2013-10-29 02:00 P.M UTC


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  • Now depends on amqp version 1.3.2.

  • select: Fixed problem where unregister did not properly remove the fd.



2013-10-24 04:00 P.M UTC


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  • Now depends on amqp version 1.3.1.

  • Redis: New option fanout_keyprefix

    This transport option is recommended for all users as it ensures that broadcast (fanout) messages sent is only seen by the current virtual host:

    Connection('redis://', transport_options={'fanout_keyprefix': True})

    However, enabling this means that you cannot send or receive messages from older Kombu versions so make sure all of your participants are upgraded and have the transport option enabled.

    This will be the default behavior in Kombu 4.0.

  • Distribution: Removed file requirements/py25.txt.

  • MongoDB: Now disables auto_start_request.

  • MongoDB: Enables use_greenlets if eventlet/gevent used.

  • Pidbox: Fixes problem where expires header was None, which is a value not supported by the amq protocol.

  • ConsumerMixin: New consumer_context method for starting the consumer without draining events.



2013-10-14 04:00 P.M BST


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  • Now depends on amqp version 1.3.

  • No longer supports Python 2.5

    The minimum Python version supported is now Python 2.6.0 for Python 2, and Python 3.3 for Python 3.

  • Dual codebase supporting both Python 2 and 3.

    No longer using 2to3, making it easier to maintain support for both versions.

  • pickle, yaml and msgpack deserialization is now disabled by default.

    This means that Kombu will by default refuse to handle any content type other than json.

    Pickle is known to be a security concern as it will happily load any object that is embedded in a pickle payload, and payloads can be crafted to do almost anything you want. The default serializer in Kombu is json but it also supports a number of other serialization formats that it will evaluate if received: including pickle.

    It was always assumed that users were educated about the security implications of pickle, but in hindsight we don’t think users should be expected to secure their services if we have the ability to be secure by default.

    By disabling any content type that the user did not explicitly want enabled we ensure that the user must be conscious when they add pickle as a serialization format to support.

    The other built-in serializers (yaml and msgpack) are also disabled even though they aren’t considered insecure [1] at this point. Instead they’re disabled so that if a security flaw is found in one of these libraries in the future, you will only be affected if you have explicitly enabled them.

    To have your consumer accept formats other than json you have to explicitly add the wanted formats to a white-list of accepted content types:

    >>> c = Consumer(conn, accept=['json', 'pickle', 'msgpack'])

    or when using synchronous access:

    >>> msg = queue.get(accept=['json', 'pickle', 'msgpack'])

    The accept argument was first supported for consumers in version 2.5.10, and first supported by Queue.get in version 2.5.15 so to stay compatible with previous versions you can enable the previous behavior:

    >>> from kombu import enable_insecure_serializers
    >>> enable_insecure_serializers()

    But note that this has global effect, so be very careful should you use it.


  • kombu.async: Experimental event loop implementation.

    This code was previously in Celery but was moved here to make it easier for async transport implementations.

    The API is meant to match the Tulip API which will be included in Python 3.4 as the asyncio module. It’s not a complete implementation obviously, but the goal is that it will be easy to change to it once that is possible.

  • Utility function kombu.common.ipublish has been removed.

    Use Producer(..., retry=True) instead.

  • Utility function kombu.common.isend_reply has been removed

    Use send_reply(..., retry=True) instead.

  • kombu.common.entry_to_queue and kombu.messaging.entry_to_queue has been removed.

    Use Queue.from_dict(name, **options) instead.

  • Redis: Messages are now restored at the end of the list.

    Contributed by Mark Lavin.

  • StdConnectionError and StdChannelError is removed

    and amqp.ConnectionError and amqp.ChannelError is used instead.

  • Message object implementation has moved to kombu.message.Message.

  • Serailization: Renamed functions encode/decode to dumps() and loads().

    For backward compatibility the old names are still available as aliases.

  • The kombu.log.anon_logger function has been removed.

    Use get_logger() instead.

  • queue_declare now returns namedtuple with queue, message_count, and consumer_count fields.

  • LamportClock: Can now set lock class

  • kombu.utils.clock: Utilities for ordering events added.

  • SimpleQueue now allows you to override the exchange type used.

    Contributed by Vince Gonzales.

  • Zookeeper transport updated to support new changes in the kazoo library.

    Contributed by Mahendra M.

  • pyamqp/librabbitmq: Transport options are now forwarded as keyword arguments

    to the underlying connection (Issue #214).

  • Transports may now distinguish between recoverable and irrecoverable connection and channel errors.

  • kombu.utils.Finalize has been removed: Use multiprocessing.util.Finalize instead.

  • Memory transport now supports the fanout exchange type.

    Contributed by Davanum Srinivas.

  • Experimental new Pyro transport (kombu.transport.pyro).

    Contributed by Tommie McAfee.

  • Eventio: Kqueue breaks in subtle ways so select is now used instead.

  • SQLAlchemy transport: Can now specify table names using the queue_tablename and message_tablename transport options.

    Contributed by Ryan Petrello.

Redis transport: Now supports using local UNIX sockets to communicate with the

Redis server (Issue #1283)

To connect using a UNIX socket you have to use the redis+socket URL-prefix: redis+socket:///tmp/redis.sock.

This functionality was merged from the celery-redis-unixsocket project. Contributed by Maxime Rouyrre.

ZeroMQ transport: drain_events now supports timeout.

Contributed by Jesper Thomschütz.



2013-10-04 03:30 P.M BST


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  • Python 3: Fixed problem with dependencies not being installed.



2013-10-04 03:30 P.M BST


Ask Solem

  • Declaration cache: Now only keeps hash of declaration so that it does not keep a reference to the channel.

  • Declaration cache: Now respects entity.can_cache_declaration attribute.

  • Fixes Python 2.5 compatibility.

  • Fixes tests after python-msgpack changes.

  • Queue.get: Now supports accept argument.



2013-08-23 05:00 P.M BST


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2013-08-16 04:00 P.M BST


Ask Solem

  • Now depends on amqp 1.0.13

  • Fixed typo in Django functional tests.

  • safe_str now returns Unicode in Python 2.x

    Fix contributed by Germán M. Bravo.

  • amqp: Transport options are now merged with arguments supplied to the connection.

  • Tests no longer depends on distribute, which was deprecated and merged back into setuptools.

    Fix contributed by Sascha Peilicke.

  • ConsumerMixin now also restarts on channel related errors.

    Fix contributed by Corentin Ardeois.



2013-06-28 03:30 P.M BST


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  • Redis: Ignore errors about keys missing in the round-robin cycle.

  • Fixed test suite errors on Python 3.

  • Fixed msgpack test failures.



2013-06-25 02:30 P.M BST


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  • Now depends on amqp 1.0.12 (Py3 compatibility issues).

  • MongoDB: Removed cause of a “database name in URI is being ignored” warning.

    Fix by Flavio Percoco Premoli

  • Adds passive option to Exchange.

    Setting this flag means that the exchange will not be declared by kombu, but that it must exist already (or an exception will be raised).

    Contributed by Rafal Malinowski

  • now gives the current hostname and not the list of available hostnames.

    Fix contributed by John Shuping.

  • pyamqp: Transport options are now forwarded as kwargs to amqp.Connection.

  • librabbitmq: Transport options are now forwarded as kwargs to librabbitmq.Connection.

  • librabbitmq: Now raises NotImplementedError if SSL is enabled.

    The librabbitmq library does not support ssl, but you can use stunnel or change to the pyamqp:// transport instead.

    Fix contributed by Dan LaMotte.

  • librabbitmq: Fixed a cyclic reference at connection close.

  • eventio: select implementation now removes bad file descriptors.

  • eventio: Fixed Py3 compatibility problems.

  • Functional tests added for py-amqp and librabbitmq transports.

  • Resource.force_close_all no longer uses a mutex.

  • Pidbox: Now ignores IconsistencyError when sending replies, as this error simply means that the client may no longer be alive.

  • Adds new Connection.collect method, that can be used to clean up after connections without I/O.

  • queue_bind is no longer called for queues bound to the “default exchange” (Issue #209).

    Contributed by Jonathan Halcrow.

  • The max_retries setting for retries was not respected correctly (off by one).



2013-04-11 06:10 P.M BST


Ask Solem

Note about upcoming changes for Kombu 3.0

Kombu 3 consumers will no longer accept pickle/yaml or msgpack by default, and you will have to explicitly enable untrusted deserializers either globally using kombu.enable_insecure_serializers(), or using the accept argument to Consumer.


  • New utility function to disable/enable untrusted serializers.

  • Consumer: accept can now be used to specify a whitelist of content types to accept.

    If the accept whitelist is set and a message is received with a content type that is not in the whitelist then a ContentDisallowed exception is raised. Note that this error can be handled by the already existing on_decode_error callback


    Consumer(accept=['pickle', 'json'])
  • Now depends on amqp 1.0.11

  • pidbox: Mailbox now supports the accept argument.

  • Redis: More friendly error for when keys are missing.

  • Connection URLs: The parser did not work well when there were multiple ‘+’ tokens.



2013-04-08 05:07 P.M BST


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  • Pidbox: Now warns if there are multiple nodes consuming from the same pidbox.

  • Adds Queue.on_declared

    A callback to be called when the queue is declared, with signature (name, messages, consumers).

  • Now uses fuzzy matching to suggest alternatives to typos in transport names.

  • SQS: Adds new transport option queue_prefix.

    Contributed by j0hnsmith.

  • pyamqp: No longer overrides verify_connection.

  • SQS: Now specifies the driver_type and driver_name attributes.

    Fix contributed by Mher Movsisyan.

  • Fixed bug with kombu.utils.retry_over_time when no errback specified.



2013-03-21 04:00 P.M UTC


Ask Solem

  • Now depends on amqp 1.0.10 which fixes a Python 3 compatibility error.

  • Redis: Fixed a possible race condition (Issue #171).

  • Redis: Ack emulation/visibility_timeout can now be disabled using a transport option.

    Ack emulation adds quite a lot of overhead to ensure data is safe even in the event of an unclean shutdown. If data loss do not worry you there is now an ack_emulation transport option you can use to disable it:

    Connection('redis://', transport_options={'ack_emulation': False})
  • SQS: Fixed boto v2.7 compatibility (Issue #207).

  • Exchange: Should not try to re-declare default exchange ("") (Issue #209).

  • SQS: Long polling is now disabled by default as it was not implemented correctly, resulting in long delays between receiving messages (Issue #202).

  • Fixed Python 2.6 incompatibility depending on exc.errno being available.

    Fix contributed by Ephemera.



2013-03-08 01:00 P.M UTC


Ask Solem

  • Now depends on amqp 1.0.9

  • Redis: A regression in 2.5.6 caused the redis transport to ignore options set in transport_options.

  • Redis: New socket_timeout transport option.

  • Redis: InconsistencyError is now regarded as a recoverable error.

  • Resource pools: Will no longer attempt to release resource that was never acquired.

  • MongoDB: Now supports the ssl option.

    Contributed by Sebastian Pawlus.



2013-02-08 01:00 P.M UTC


Ask Solem

  • Now depends on amqp 1.0.8 which works around a bug found on some Python 2.5 installations where 2**32 overflows to 0.



2013-02-07 05:00 P.M UTC


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SQS: Now supports long polling (Issue #176).

The polling interval default has been changed to 0 and a new transport option (wait_time_seconds) has been added. This parameter specifies how long to wait for a message from SQS, and defaults to 20 seconds, which is the maximum value currently allowed by Amazon SQS.

Contributed by James Saryerwinnie.

  • SQS: Now removes unpickleable fields before restoring messages.

  • Consumer.__exit__ now ignores exceptions occurring while canceling the consumer.

  • Virtual: Routing keys can now consist of characters also used in regular expressions (e.g. parens) (Issue #194).

  • Virtual: Fixed compression header when restoring messages.

    Fix contributed by Alex Koshelev.

  • Virtual: ack/reject/requeue now works while using basic_get.

  • Virtual: Message.reject is now supported by virtual transports (requeue depends on individual transport support).

  • Fixed typo in hack used for static analyzers.

    Fix contributed by Basil Mironenko.



2012-12-10 12:35 P.M UTC


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  • Fixed problem with connection clone and multiple URLs (Issue #182).

    Fix contributed by Dane Guempel.

  • zeromq: Now compatible with libzmq 3.2.x.

    Fix contributed by Andrey Antukh.

  • Fixed Python 3 installation problem (Issue #187).



2012-11-29 12:35 P.M UTC


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  • Pidbox: Fixed compatibility with Python 2.6



2012-11-29 12:35 P.M UTC


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2012-11-29 12:35 P.M UTC


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  • [Redis] Fixed connection leak and added a new ‘max_connections’ transport option.



2012-11-28 12:45 P.M UTC


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  • Fixed bug where return value of Queue.as_dict could not be serialized with JSON (Issue #177).



2012-11-27 04:00 P.M UTC


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  • py-amqp is now the new default transport, replacing amqplib.

    The new py-amqp library is a fork of amqplib started with the following goals:

    • Uses AMQP 0.9.1 instead of 0.8

    • Support for heartbeats (Issue #79 + Issue #131)

    • Automatically revives channels on channel errors.

    • Support for all RabbitMQ extensions
      • Consumer Cancel Notifications (Issue #131)

      • Publisher Confirms (Issue #131).

      • Exchange-to-exchange bindings: exchange_bind / exchange_unbind.

    • API compatible with librabbitmq so that it can be used as a pure-python replacement in environments where rabbitmq-c cannot be compiled. librabbitmq will be updated to support all the same features as py-amqp.

  • Support for using multiple connection URL’s for failover.

    The first argument to Connection can now be a list of connection URLs:

    Connection(['amqp://foo', 'amqp://bar'])

    or it can be a single string argument with several URLs separated by semicolon:


    There is also a new keyword argument failover_strategy that defines how ensure_connection()/ ensure()/kombu.Connection.autoretry() will reconnect in the event of connection failures.

    The default reconnection strategy is round-robin, which will simply cycle through the list forever, and there’s also a shuffle strategy that will select random hosts from the list. Custom strategies can also be used, in that case the argument must be a generator yielding the URL to connect to.


  • Now supports PyDev, PyCharm, pylint and other static code analysis tools.

  • Queue now supports multiple bindings.

    You can now have multiple bindings in the same queue by having the second argument be a list:

    from kombu import binding, Queue
    Queue('name', [
        binding(Exchange('E1'), routing_key='foo'),
        binding(Exchange('E1'), routing_key='bar'),
        binding(Exchange('E2'), routing_key='baz'),

    To enable this, helper methods have been added:

    Contributed by Rumyana Neykova.

  • Custom serializers can now be registered using Setuptools entry-points.

  • New kombu.common.QoS class used as a thread-safe way to manage changes to a consumer or channels prefetch_count.

    This was previously an internal class used in Celery now moved to the kombu.common module.

  • Consumer now supports a on_message callback that can be used to process raw messages (not decoded).

    Other callbacks specified using the callbacks argument, and the receive method will be not be called when a on message callback is present.

  • New utility kombu.common.ignore_errors() ignores connection and channel errors.

    Must only be used for cleanup actions at shutdown or on connection loss.

  • Support for exchange-to-exchange bindings.

    The Exchange entity gained bind_to and unbind_from methods:

    e1 = Exchange('A')(connection)
    e2 = Exchange('B')(connection)
    e2.bind_to(e1, routing_key='rkey', arguments=None)
    e2.unbind_from(e1, routing_key='rkey', arguments=None)

    This is currently only supported by the pyamqp transport.

    Contributed by Rumyana Neykova.



2012-11-22 06:00 P.M UTC


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  • The previous versions connection pool changes broke Redis support so that it would always connect to localhost (default setting) no matter what connection parameters were provided (Issue #176).



2012-11-21 03:00 P.M UTC


Ask Solem

  • Redis: Fixed race condition that could occur while trying to restore messages (Issue #171).

    Fix contributed by Ollie Walsh.

  • Redis: Each channel is now using a specific connection pool instance, which is disconnected on connection failure.

  • ProducerPool: Fixed possible dead-lock in the acquire method.

  • ProducerPool: force_close_all no longer tries to call the non-existent Producer._close.

  • librabbitmq: Now implements transport.verify_connection so that connection pools will not give back connections that are no longer working.

  • New and better repr() for Queue and Exchange objects.

  • Python 3: Fixed problem with running the unit test suite.

  • Python 3: Fixed problem with JSON codec.



2012-11-02 05:00 P.M UTC


Ask Solem

  • Redis: Improved fair queue cycle implementation (Issue #166).

    Contributed by Kevin McCarthy.

  • Redis: Unacked message restore limit is now unlimited by default.

    Also, the limit can now be configured using the unacked_restore_limit transport option:

    Connection('redis://', transport_options={
        'unacked_restore_limit': 100,
    A limit of 100 means that the consumer will restore at most 100
    messages at each pass.
  • Redis: Now uses a mutex to ensure only one consumer restores messages at a time.

    The mutex expires after 5 minutes by default, but can be configured using the unacked_mutex_expire transport option.

  • LamportClock.adjust now returns the new clock value.

  • Heartbeats can now be specified in URLs.

    Fix contributed by Mher Movsisyan.

  • Kombu can now be used with PyDev, PyCharm and other static analysis tools.

  • Fixes problem with msgpack on Python 3 (Issue #162).

    Fix contributed by Jasper Bryant-Greene

  • amqplib: Fixed bug with timeouts when SSL is used in non-blocking mode.

    Fix contributed by Mher Movsisyan



2012-09-18 03:00 P.M BST


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  • Virtual: Unknown exchanges now default to ‘direct’ when sending a message.

  • MongoDB: Fixed memory leak when merging keys stored in the db (Issue #159)

    Fix contributed by Michael Korbakov.

  • MongoDB: Better index for MongoDB transport (Issue #158).

    This improvement will create a new compund index for queue and _id in order to be able to use both indexed fields for getting a new message (using queue field) and sorting by _id. It’ll be necessary to manually delete the old index from the collection.

    Improvement contributed by rmihael



2012-09-12 03:00 P.M BST


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  • Adds additional compatibility dependencies:

    • Python <= 2.6:

      • importlib

      • ordereddict

    • Python <= 2.5

      • simplejson



2012-08-30 03:36 P.M BST


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  • Last version broke installtion on PyPy and Jython due to test requirements clean-up.



2012-08-29 04:00 P.M BST


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  • amqplib: Fixed a bug with asynchronously reading large messages.

  • pyamqp: Now requires amqp 0.9.3

  • Cleaned up test requirements.



2012-08-25 10:30 P.M BST


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  • Fixed problem with amqp transport alias (Issue #154).



2012-08-24 05:00 P.M BST


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  • Having an empty transport name broke in 2.4.1.



2012-08-24 04:00 P.M BST


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  • Redis: Fixed race condition that could cause the consumer to crash (Issue #151)

    Often leading to the error message "could not convert string to float"

  • Connection retry could cause an inifite loop (Issue #145).

  • The amqp alias is now resolved at runtime, so that eventlet detection works even if patching was done later.



2012-08-17 08:00 P.M BST


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  • New experimental ZeroMQ <kombu.transport.zmq transport.

    Contributed by John Watson.

  • Redis: Ack timed-out messages were not restored when using the eventloop.

  • Now uses pickle protocol 2 by default to be cross-compatible with Python 3.

    The protocol can also now be changed using the PICKLE_PROTOCOL environment variable.

  • Adds Transport.supports_ev attribute.

  • Pika: Queue purge was not working properly.

    Fix contributed by Steeve Morin.

  • Pika backend was no longer working since Kombu 2.3

    Fix contributed by Steeve Morin.



2012-08-01 06:00 P.M BST


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  • Fixes problem with deserialization in Python 3.



2012-08-01 04:00 P.M BST


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  • librabbitmq: Can now handle messages that does not have a content_encoding/content_type set (Issue #149).

    Fix contributed by C Anthony Risinger.

  • Beanstalk: Now uses localhost by default if the URL does not contain a host.



2012-07-24 03:50 P.M BST


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  • New pyamqp:// transport!

    The new py-amqp library is a fork of amqplib started with the following goals:

    • Uses AMQP 0.9.1 instead of 0.8

    • Should support all RabbitMQ extensions

    • API compatible with librabbitmq so that it can be used as a pure-python replacement in environments where rabbitmq-c cannot be compiled.

    If you start using use py-amqp instead of amqplib you can enjoy many advantages including:

    • Heartbeat support (Issue #79 + Issue #131)

    • Consumer Cancel Notifications (Issue #131)

    • Publisher Confirms

    amqplib has not been updated in a long while, so maintaining our own fork ensures that we can quickly roll out new features and fixes without resorting to monkey patching.

    To use the py-amqp transport you must install the amqp library:

    $ pip install amqp

    and change the connection URL to use the correct transport:

    >>> conn = Connection('pyamqp://guest:guest@localhost//')

    The pyamqp:// transport will be the default fallback transport in Kombu version 3.0, when librabbitmq is not installed, and librabbitmq will also be updated to support the same features.

  • Connection now supports heartbeat argument.

    If enabled you must make sure to manually maintain heartbeats by calling the Connection.heartbeat_check at twice the rate of the specified heartbeat interval.

    E.g. if you have Connection(heartbeat=10), then you must call Connection.heartbeat_check() every 5 seconds.

    if the server has not sent heartbeats at a suitable rate then the heartbeat check method must raise an error that is listed in Connection.connection_errors.

    The attribute Connection.supports_heartbeats has been added for the ability to inspect if a transport supports heartbeats or not.

    Calling heartbeat_check on a transport that does not support heartbeats results in a noop operation.

  • SQS: Fixed bug with invalid characters in queue names.

    Fix contributed by Zach Smith.

  • utils.reprcall: Fixed typo where kwargs argument was an empty tuple by default, and not an empty dict.



2012-07-10 05:00 P.M BST


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  • Adds kombu.messaging.entry_to_queue for compat with previous versions.



2012-07-10 05:00 P.M BST


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  • Pidbox: Now sets queue expire at 10 seconds for reply queues.

  • EventIO: Now ignores ValueError raised by epoll unregister.

  • MongoDB: Fixes Issue #142

    Fix by Flavio Percoco Premoli



2012-07-05 04:00 P.M BST


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  • Support for msgpack-python 0.2.0 (Issue #143)

    The latest msgpack version no longer supports Python 2.5, so if you’re still using that you need to depend on an earlier msgpack-python version.

    Fix contributed by Sebastian Insua

  • maybe_declare() no longer caches entities with the auto_delete flag set.

  • New experimental filesystem transport.

    Contributed by Bobby Beever.

  • Virtual Transports: Now support anonymous queues and exchanges.



2012-06-24 05:00 P.M BST


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  • BrokerConnection now renamed to Connection.

    The name Connection has been an alias for a very long time, but now the rename is official in the documentation as well.

    The Connection alias has been available since version 1.1.3, and BrokerConnection will still work and is not deprecated.

  • Connection.clone() now works for the sqlalchemy transport.

  • kombu.common.eventloop(), kombu.utils.uuid(), and kombu.utils.url.parse_url() can now be imported from the kombu module directly.

  • Pidbox transport callback after_reply_message_received now happens in a finally block.

  • Trying to use the librabbitmq:// transport will now show the right name in the ImportError if librabbitmq is not installed.

    The librabbitmq falls back to the older pylibrabbitmq name for compatibility reasons and would therefore show No module named pylibrabbitmq instead of librabbitmq.



2012-06-22 02:30 P.M BST


Ask Solem

  • Now depends on anyjson 0.3.3

  • Json serializer: Now passes buffer objects directly, since this is supported in the latest anyjson version.

  • Fixes blocking epoll call if timeout was set to 0.

    Fix contributed by John Watson.

  • now takes requirements from the requirements/ directory.

  • The distribution directory contrib/ is now renamed to extra/



2012-06-21 01:00 P.M BST


Ask Solem

  • SQS: Default visibility timeout is now 30 minutes.

    Since we have ack emulation the visibility timeout is only in effect if the consumer is abrubtly terminated.

  • retry argument to Producer.publish now works properly, when the declare argument is specified.

  • Json serializer: didn’t handle buffer objects (Issue #135).

    Fix contributed by Jens Hoffrichter.

  • Virtual: Now supports passive argument to exchange_declare.

  • Exchange & Queue can now be bound to connections (which will use the default channel):

    >>> exchange = Exchange('name')
    >>> bound_exchange = exchange(connection)
    >>> bound_exchange.declare()
  • SimpleQueue & SimpleBuffer can now be bound to connections (which will use the default channel).

  • Connection.manager.get_bindings now works for librabbitmq and pika.

  • Adds new transport info attributes:

    • Transport.driver_type

      Type of underlying driver, e.g. “amqp”, “redis”, “sql”.

    • Transport.driver_name

      Name of library used e.g. “amqplib”, “redis”, “pymongo”.

    • Transport.driver_version()

      Version of underlying library.



2012-06-07 03:10 P.M BST


Ask Solem

Important Notes

  • The canonical source code repository has been moved to

  • Pidbox: Exchanges used by pidbox are no longer auto_delete.

    Auto delete has been described as a misfeature, and therefore we have disabled it.

    For RabbitMQ users old exchanges used by pidbox must be removed, these are named mailbox_name.pidbox, and reply.mailbox_name.pidbox.

    The following command can be used to clean up these exchanges:

    $ VHOST=/ URL=amqp:// python -c'import sys,kombu;[kombu.Connection(
            for x in sys.argv[1:-1]]' \
        $(sudo rabbitmqctl -q list_exchanges -p "$VHOST" \
        | grep \.pidbox | awk '{print $1}') "$URL"

    The VHOST variable must be set to the target RabbitMQ virtual host, and the URL must be the AMQP URL to the server.

  • The amqp transport alias will now use librabbitmq if installed.

    py-librabbitmq is a fast AMQP client for Python using the librabbitmq C library.

    It can be installed by:

    $ pip install librabbitmq

    It will not be used if the process is monkey patched by eventlet/gevent.


  • Redis: Ack emulation improvements.

    Reducing the possibility of data loss.

    Acks are now implemented by storing a copy of the message when the message is consumed. The copy is not removed until the consumer acknowledges or rejects it.

    This means that unacknowledged messages will be redelivered either when the connection is closed, or when the visibility timeout is exceeded.

    • Visibility timeout

      This is a timeout for acks, so that if the consumer does not ack the message within this time limit, the message is redelivered to another consumer.

      The timeout is set to one hour by default, but can be changed by configuring a transport option:

      >>> Connection('redis://', transport_options={
      ...     'visibility_timeout': 1800,  # 30 minutes
      ... })

    NOTE: Messages that have not been acked will be redelivered if the visibility timeout is exceeded, for Celery users this means that ETA/countdown tasks that are scheduled to execute with a time that exceeds the visibility timeout will be executed twice (or more). If you plan on using long ETA/countdowns you should tweak the visibility timeout accordingly:

    BROKER_TRANSPORT_OPTIONS = {'visibility_timeout': 18000}  # 5 hours

    Setting a long timeout means that it will take a long time for messages to be redelivered in the event of a power failure, but if so happens you could temporarily set the visibility timeout lower to flush out messages when you start up the systems again.

  • Experimental Apache ZooKeeper transport

    More information is in the module reference: kombu.transport.zookeeper.

    Contributed by Mahendra M.

  • Redis: Priority support.

    The message’s priority field is now respected by the Redis transport by having multiple lists for each named queue. The queues are then consumed by in order of priority.

    The priority field is a number in the range of 0 - 9, where 0 is the default and highest priority.

    The priority range is collapsed into four steps by default, since it is unlikely that nine steps will yield more benefit than using four steps. The number of steps can be configured by setting the priority_steps transport option, which must be a list of numbers in sorted order:

    >>> x = Connection('redis://', transport_options={
    ...     'priority_steps': [0, 2, 4, 6, 8, 9],
    ... })

    Priorities implemented in this way is not as reliable as priorities on the server side, which is why nickname the feature “quasi-priorities”; Using routing is still the suggested way of ensuring quality of service, as client implemented priorities fall short in a number of ways, e.g. if the worker is busy with long running tasks, has prefetched many messages, or the queues are congested.

    Still, it is possible that using priorities in combination with routing can be more beneficial than using routing or priorities alone. Experimentation and monitoring should be used to prove this.

    Contributed by Germán M. Bravo.

  • Redis: Now cycles queues so that consuming is fair.

    This ensures that a very busy queue won’t block messages from other queues, and ensures that all queues have an equal chance of being consumed from.

    This used to be the case before, but the behavior was accidentally changed while switching to using blocking pop.

  • Redis: Auto delete queues that are bound to fanout exchanges is now deleted at channel.close.

  • amqplib: Refactored the drain_events implementation.

  • Pidbox: Now uses connection.default_channel.

  • Pickle serialization: Can now decode buffer objects.

  • Exchange/Queue declarations can now be cached even if the entity is non-durable.

    This is possible because the list of cached declarations are now kept with the connection, so that the entities will be redeclared if the connection is lost.

  • Kombu source code now only uses one-level of explicit relative imports.


  • eventio: Now ignores ENOENT raised by epoll.register, and EEXIST from epoll.unregister.

  • eventio: kqueue now ignores KeyError on unregister.

  • Redis: Message.reject now supports the requeue argument.

  • Redis: Remove superfluous pipeline call.

    Fix contributed by Thomas Johansson.

  • Redis: Now sets redelivered header for redelivered messages.

  • Now always makes sure references to sys.exc_info() is removed.

  • Virtual: The compression header is now removed before restoring messages.

  • More tests for the SQLAlchemy backend.

    Contributed by Franck Cuny.

  • Url parsing did not handle MongoDB URLs properly.

    Fix contributed by Flavio Percoco Premoli.

  • Beanstalk: Ignore default tube when reserving.

    Fix contributed by Zhao Xiaohong.

Nonblocking consume support

librabbitmq, amqplib and redis transports can now be used non-blocking.

The interface is very manual, and only consuming messages is non-blocking so far.

The API should not be regarded as stable or final in any way. It is used by Celery which has very limited needs at this point. Hopefully we can introduce a proper callback-based API later.

  • Transport.eventmap

    Is a map of fd -> callback(fileno, event) to register in an eventloop.

  • Transport.on_poll_start()

    Is called before every call to poll. The poller must support register(fd, callback) and unregister(fd) methods.

  • Transport.on_poll_start(poller)

    Called when the hub is initialized. The poller argument must support the same interface as kombu.utils.eventio.poll.

  • Connection.ensure_connection now takes a callback argument which is called for every loop while the connection is down.

  • Adds connection.drain_nowait

    This is a non-blocking alternative to drain_events, but only supported by amqplib/librabbitmq.

  • drain_events now sets connection.more_to_read if there is more data to read.

    This is to support eventloops where other things must be handled between draining events.



2012-05-06 03:06 P.M BST


Ask Solem

  • Bound Exchange/Queue’s are now pickleable.

  • Consumer/Producer can now be instantiated without a channel, and only later bound using .revive(channel).

  • ProducerPool now takes Producer argument.

  • fxrange() now counts forever if the stop argument is set to None. (fxrange is like xrange but for decimals).

  • Auto delete support for virtual transports were incomplete and could lead to problems so it was removed.

  • Cached declarations (maybe_declare()) are now bound to the underlying connection, so that entities are redeclared if the connection is lost.

    This also means that previously uncacheable entities (e.g. non-durable) can now be cached.

  • compat ConsumerSet: can now specify channel.



2012-04-27 06:00 P.M BST


Ask Solem

  • compat consumerset now accepts optional channel argument.



2012-04-23 01:30 P.M BST


Ask Solem

  • SQLAlchemy transport was not working correctly after URL parser change.

  • maybe_declare now stores cached declarations per underlying connection instead of globally, in the rare case that data disappears from the broker after connection loss.

  • Django: Added South migrations.

    Contributed by Joseph Crosland.



2012-04-13 03:30 P.M BST


Ask Solem

  • The url parser removed more than the first leading slash (Issue #121).

  • SQLAlchemy: Can now specify url using + separator


  • Better support for anonymous queues (Issue #116).

    Contributed by Michael Barrett.

  • Connection.as_uri now quotes url parts (Issue #117).

  • Beanstalk: Can now set message TTR as a message property.

    Contributed by Andrii Kostenko



2012-04-03 04:00 P.M GMT


Ask Solem

  • MongoDB: URL parsing are now delegated to the pymongo library (Fixes Issue #103 and Issue #87).

    Fix contributed by Flavio Percoco Premoli and James Sullivan

  • SQS: A bug caused SimpleDB to be used even if sdb persistence was not enabled (Issue #108).

    Fix contributed by Anand Kumria.

  • Django: Transaction was committed in the wrong place, causing data cleanup to fail (Issue #115).

    Fix contributed by Daisuke Fujiwara.

  • MongoDB: Now supports replica set URLs.

    Contributed by Flavio Percoco Premoli.

  • Redis: Now raises a channel error if a queue key that is currently being consumed from disappears.

    Fix contributed by Stephan Jaekel.

  • All transport ‘channel_errors’ lists now includes kombu.exception.StdChannelError.

  • All kombu exceptions now inherit from a common KombuError.



2012-03-20 03:00 P.M GMT


Ask Solem

  • Fixes Jython compatibility issues.

  • Fixes Python 2.5 compatibility issues.



2012-03-01 01:00 P.M GMT


Ask Solem

  • amqplib: Last version broke SSL support.



2012-02-24 02:00 P.M GMT


Ask Solem

  • Connection URLs now supports encoded characters.

  • Fixed a case where connection pool could not recover from connection loss.

    Fix contributed by Florian Munz.

  • We now patch amqplib’s __del__ method to skip trying to close the socket if it is not connected, as this resulted in an annoying warning.

  • Compression can now be used with binary message payloads.

    Fix contributed by Steeve Morin.



2012-02-04 10:38 P.M GMT


Ask Solem

  • MongoDB: Now supports fanout (broadcast) (Issue #98).

    Contributed by Scott Lyons.

  • amqplib: Now detects broken connections by using MSG_PEEK.

  • pylibrabbitmq: Now supports basic_get (Issue #97).

  • gevent: Now always uses the select polling backend.

  • pika transport: Now works with pika 0.9.5 and 0.9.6dev.

    The old pika transport (supporting 0.5.x) is now available as alias oldpika.

    (Note terribly latency has been experienced with the new pika versions, so this is still an experimental transport).

  • Virtual transports: can now set polling interval via the transport options (Issue #96).


    >>> Connection('sqs://', transport_options={
    ...     'polling_interval': 5.0})

    The default interval is transport specific, but usually 1.0s (or 5.0s for the Django database transport, which can also be set using the KOMBU_POLLING_INTERVAL setting).

  • Adds convenience function: kombu.common.eventloop().



2012-01-15 06:34 P.M GMT


Ask Solem

Important Notes

Python Compatibility

  • No longer supports Python 2.4.

    Users of Python 2.4 can still use the 1.x series.

    The 1.x series has entered bugfix-only maintenance mode, and will stay that way as long as there is demand, and a willingness to maintain it.

New Transports

  • django-kombu is now part of Kombu core.

    The Django message transport uses the Django ORM to store messages.

    It uses polling, with a default polling interval of 5 seconds. The polling interval can be increased or decreased by configuring the KOMBU_POLLING_INTERVAL Django setting, which is the polling interval in seconds as an int or a float. Note that shorter polling intervals can cause extreme strain on the database: if responsiveness is needed you shall consider switching to a non-polling transport.

    To use it you must use transport alias "django", or as a URL:


    and then add kombu.transport.django to INSTALLED_APPS, and run syncdb to create the necessary database tables.


    If you have previously used django-kombu, then the entry in INSTALLED_APPS must be changed from djkombu to kombu.transport.django:

        # …,

    If you have previously used django-kombu, then there is no need to recreate the tables, as the old tables will be fully compatible with the new version.

  • kombu-sqlalchemy is now part of Kombu core.

    This change requires no code changes given that the sqlalchemy transport alias is used.


  • kombu.mixins.ConsumerMixin is a mixin class that lets you easily write consumer programs and threads.

    See Examples and Consumers.

  • SQS Transport: Added support for SQS queue prefixes (Issue #84).

    The queue prefix can be set using the transport option queue_name_prefix:

    BrokerTransport('SQS://', transport_options={
        'queue_name_prefix': 'myapp'})

    Contributed by Nitzan Miron.

  • Producer.publish now supports automatic retry.

    Retry is enabled by the reply argument, and retry options set by the retry_policy argument:

    exchange = Exchange('foo')
    producer.publish(message, exchange=exchange, retry=True,
                     declare=[exchange], retry_policy={
                        'interval_start': 1.0})

    See ensure() for a list of supported retry policy options.

  • Producer.publish now supports a declare keyword argument.

    This is a list of entities (Exchange, or Queue) that should be declared before the message is published.


  • Redis transport: Timeout was multiplied by 1000 seconds when using select for event I/O (Issue #86).



2011-11-30 01:00 P.M GMT


Ask Solem

  • Fixes issue with kombu.compat introduced in 1.5.0 (Issue #83).

  • Adds the ability to disable content_types in the serializer registry.

    Any message with a content type that is disabled will be refused. One example would be to disable the Pickle serializer:

    >>> from kombu.serialization import registry
    # by name
    >>> registry.disable('pickle')
    # or by mime-type.
    >>> registry.disable('application/x-python-serialize')



2011-11-27 06:00 P.M GMT


Ask Solem

  • kombu.pools: Fixed a bug resulting in resources not being properly released.

    This was caused by the use of __hash__ to distinguish them.

  • Virtual transports: Dead-letter queue is now disabled by default.

    The dead-letter queue was enabled by default to help application authors, but now that Kombu is stable it should be removed. There are after all many cases where messages should just be dropped when there are no queues to buffer them, and keeping them without supporting automatic cleanup is rather considered a resource leak than a feature.

    If wanted the dead-letter queue can still be enabled, by using the deadletter_queue transport option:

    >>> x = Connection('redis://',
    ...       transport_options={'deadletter_queue': 'ae.undeliver'})

    In addition, an UndeliverableWarning is now emitted when the dead-letter queue is enabled and a message ends up there.

    Contributed by Ionel Maries Cristian.

  • MongoDB transport now supports Replicasets (Issue #81).

    Contributed by Ivan Metzlar.

  • The Connection.ensure methods now accepts a max_retries value of 0.

    A value of 0 now means do not retry, which is distinct from None which means retry indefinitely.

    Contributed by Dan McGee.

  • SQS Transport: Now has a lowercase sqs alias, so that it can be used with broker URLs (Issue #82).

    Fix contributed by Hong Minhee

  • SQS Transport: Fixes KeyError on message acknowledgments (Issue #73).

    The SQS transport now uses UUID’s for delivery tags, rather than a counter.

    Fix contributed by Brian Bernstein.

  • SQS Transport: Unicode related fixes (Issue #82).

    Fix contributed by Hong Minhee.

  • Redis version check could crash because of improper handling of types (Issue #63).

  • Fixed error with Resource.force_close_all when resources were not yet properly initialized (Issue #78).



2011-10-27 10:00 P.M BST


Ask Solem

  • Fixes bug in ProducerPool where too many resources would be acquired.



2011-10-26 05:00 P.M BST


Ask Solem

  • Eventio: Polling should ignore errno.EINTR

  • SQS: str.encode did only start accepting kwargs after Py2.7.

  • simple_task_queue example didn’t run correctly (Issue #72).

    Fix contributed by Stefan Eletzhofer.

  • Empty messages would not raise an exception not able to be handled by on_decode_error (Issue #72)

    Fix contributed by Christophe Chauvet.

  • CouchDB: Properly authenticate if user/password set (Issue #70)

    Fix contributed by Rafael Duran Castaneda

  • Connection.Consumer had the wrong signature.

    Fix contributed by Pavel Skvazh



2011-09-26 04:00 P.M BST


Ask Solem

  • 1.4.0 broke the producer pool, resulting in new connections being established for every acquire.



2011-09-22 05:00 P.M BST


Ask Solem

  • Adds module kombu.mixins.

    This module contains a ConsumerMixin class that can be used to easily implement a message consumer thread that consumes messages from one or more kombu.Consumer instances.

  • New example: Task Queue Example

    Using the ConsumerMixin, default channels and the global connection pool to demonstrate new Kombu features.

  • MongoDB transport did not work with MongoDB >= 2.0 (Issue #66)

    Fix contributed by James Turk.

  • Redis-py version check did not account for beta identifiers in version string.

    Fix contributed by David Ziegler.

  • Producer and Consumer now accepts a connection instance as the first argument.

    The connections default channel will then be used.

    In addition shortcut methods has been added to Connection:

    >>> connection.Producer(exchange)
    >>> connection.Consumer(queues=..., callbacks=...)
  • Connection has aquired a connected attribute that can be used to check if the connection instance has established a connection.

  • ConnectionPool.acquire_channel now returns the connections default channel rather than establising a new channel that must be manually handled.

  • Added kombu.common.maybe_declare

    maybe_declare(entity) declares an entity if it has not previously been declared in the same process.

  • kombu.compat.entry_to_queue() has been moved to kombu.common

  • New module kombu.clocks now contains an implementation of Lamports logical clock.



2011-09-16 06:00 P.M BST


Ask Solem

  • Python 3: AMQP_PROTOCOL_HEADER must be bytes, not str.



2011-09-16 06:00 P.M BST


Ask Solem

  • Fixes syntax error in pools.reset



2011-09-15 02:00 P.M BST


Ask Solem

  • pools.reset did not support after forker arguments.



2011-09-10 01:00 P.M BST


Mher Movsisyan

  • Broke Python 2.5 compatibility by importing parse_qsl from urlparse

  • Connection.default_channel is now closed when connection is revived after connection failures.

  • Pika: Channel now supports the connection.client attribute as required by the simple interface.

  • pools.set_limit now raises an exception if the limit is lower than the previous limit.

  • pools.set_limit no longer resets the pools.



2011-10-07 03:00 P.M BST


Ask Solem

  • Last release broke after fork for pool reinitialization.

  • Producer/Consumer now has a connection attribute, giving access to the Connection of the instance.

  • Pika: Channels now have access to the underlying Connection instance using channel.connection.client.

    This was previously required by the Simple classes and is now also required by Consumer and Producer.

  • Connection.default_channel is now closed at object revival.

  • Adds kombu.clocks.LamportClock.

  • compat.entry_to_queue has been moved to new module kombu.common.



2011-10-05 01:00 P.M BST


Ask Solem

  • Broker connection info can be now be specified using URLs

    The broker hostname can now be given as a URL instead, of the format:


    for example the default broker is expressed as:

    >>> Connection('amqp://guest:guest@localhost:5672//')

    Transport defaults to amqp, and is not required. user, password, port and virtual_host is also not mandatory and will default to the corresponding transports default.


    Note that the path component (virtual_host) always starts with a forward-slash. This is necessary to distinguish between the virtual host ‘’ (empty) and ‘/’, which are both acceptable virtual host names.

    A virtual host of ‘/’ becomes:

    .. code-block:: text


    and a virtual host of ‘’ (empty) becomes:


    So the leading slash in the path component is always required.

  • Now comes with default global connection and producer pools.

    The acquire a connection using the connection parameters from a Connection:

    >>> from kombu import Connection, connections
    >>> connection = Connection('amqp://guest:guest@localhost//')
    >>> with connections[connection].acquire(block=True):
    ...     # do something with connection

    To acquire a producer using the connection parameters from a Connection:

    >>> from kombu import Connection, producers
    >>> connection = Connection('amqp://guest:guest@localhost//')
    >>> with producers[connection].acquire(block=True):
    ...     producer.publish({'hello': 'world'}, exchange='hello')

    Acquiring a producer will in turn also acquire a connection from the associated pool in connections, so you the number of producers is bound the same limit as number of connections.

    The default limit of 100 connections per connection instance can be changed by doing:

    >>> from kombu import pools
    >>> pools.set_limit(10)

    The pool can also be forcefully closed by doing:

    >>> from kombu import pools
    >>> pool.reset()
  • SQS Transport: Persistence using SimpleDB is now disabled by default, after reports of unstable SimpleDB connections leading to errors.

  • Producer can now be used as a context manager.

  • Producer.__exit__ now properly calls release instead of close.

    The previous behavior would lead to a memory leak when using the kombu.pools.ProducerPool

  • Now silences all exceptions from import ctypes to match behaviour of the standard Python uuid module, and avoid passing on MemoryError exceptions on SELinux-enabled systems (Issue #52 + Issue #53)

  • amqp is now an alias to the amqplib transport.

  • kombu.syn.detect_environment now returns ‘default’, ‘eventlet’, or ‘gevent’ depending on what monkey patches have been installed.

  • Serialization registry has new attribute type_to_name so it is possible to lookup serializater name by content type.

  • Exchange argument to Producer.publish can now be an Exchange instance.

  • compat.Publisher now supports the channel keyword argument.

  • Acking a message on some transports could lead to KeyError being raised (Issue #57).

  • Connection pool: Connections are no long instantiated when the pool is created, but instantiated as needed instead.

  • Tests now pass on PyPy.

  • Connection.as_uri now includes the password if the keyword argument include_password is set.

  • Virtual transports now comes with a default default_connection_params attribute.



2011-07-29 12:52 P.M BST


Ask Solem

  • Now depends on amqplib >= 1.0.0.

  • Redis: Now automatically deletes auto_delete queues at basic_cancel.

  • serialization.unregister added so it is possible to remove unwanted seralizers.

  • Fixes MemoryError while importing ctypes on SELinux (Issue #52).

  • Connection.autoretry is a version of ensure that works with arbitrary functions (i.e. it does not need an associated object that implements the revive method.

    Example usage:

    channel =
        ret, channel = connection.autoretry(send_messages, channel=channel)
  • ConnectionPool.acquire no longer force establishes the connection.

    The connection will be established as needed.

  • Connection.ensure now supports an on_revive callback that is applied whenever the connection is re-established.

  • Consumer.consuming_from(queue) returns True if the Consumer is consuming from queue.

  • Consumer.cancel_by_queue did not remove the queue from queues.

  • compat.ConsumerSet.add_queue_from_dict now automatically declared the queue if auto_declare set.



2011-07-15 12:00 P.M BST


Ask Solem

  • Virtual: Fixes cyclic reference in Channel.close (Issue #49).

  • Producer.publish: Can now set additional properties using keyword arguments (Issue #48).

  • Adds Queue.no_ack option to control the no_ack option for individual queues.

  • Recent versions broke pylibrabbitmq support.

  • SimpleQueue and SimpleBuffer can now be used as contexts.

  • Test requirements specifies PyYAML==3.09 as 3.10 dropped Python 2.4 support

  • Now properly reports default values in



2011-06-13 04:00 P.M BST


Ask Solem

  • Redis: Fixes issue introduced in 1.1.4, where a redis connection failure could leave consumer hanging forever.

  • SQS: Now supports fanout messaging by using SimpleDB to store routing tables.

    This can be disabled by setting the supports_fanout transport option:

    >>> Connection(transport='SQS',
    ...            transport_options={'supports_fanout': False})
  • SQS: Now properly deletes a message when a message is acked.

  • SQS: Can now set the Amazon AWS region, by using the region transport option.

  • amqplib: Now uses localhost as default hostname instead of raising an error.



2011-06-07 06:00 P.M BST


Ask Solem

  • Fixes compatibility with redis-py 2.4.4.



2011-06-07 04:00 P.M BST


Ask Solem

  • Redis transport: Now requires redis-py version 2.4.4 or later.

  • New Amazon SQS transport added.


    >>> conn = Connection(transport='SQS',
    ...                   userid=aws_access_key_id,
    ...                   password=aws_secret_access_key)

    The environment variables AWS_ACCESS_KEY_ID and AWS_SECRET_ACCESS_KEY are also supported.

  • librabbitmq transport: Fixes default credentials support.

  • amqplib transport: Now supports login_method for SSL auth.

    Connection now supports the login_method keyword argument.

    Default login_method is AMQPLAIN.



2011-04-21 04:00 P.M CEST


Ask Solem

  • Redis: Consuming from multiple connections now works with Eventlet.

  • Redis: Can now perform channel operations while the channel is in BRPOP/LISTEN mode (Issue #35).

    Also the async BRPOP now times out after 1 second, this means that canceling consuming from a queue/starting consuming from additional queues has a latency of up to one second (BRPOP does not support subsecond timeouts).

  • Virtual: Allow channel objects to be closed multiple times without error.

  • amqplib: AttributeError has been added to the list of known connection related errors (Connection.connection_errors).

  • amqplib: Now converts SSLError timeout errors to socket.timeout (

  • Ensures cyclic references are destroyed when the connection is closed.



2011-04-06 04:00 P.M CEST


Ask Solem

  • Redis: Fixes serious issue where messages could be lost.

    The issue could happen if the message exceeded a certain number of kilobytes in size.

    It is recommended that all users of the Redis transport should upgrade to this version, even if not currently experiencing any issues.



2011-04-05 03:51 P.M CEST


Ask Solem

  • 1.1.0 started using Queue.LifoQueue which is only available in Python 2.6+ (Issue #33). We now ship with our own LifoQueue.



2011-04-05 01:05 P.M CEST


Ask Solem

Important Notes

  • Virtual transports: Message body is now base64 encoded by default (Issue #27).

    This should solve problems sending binary data with virtual transports.

    Message compatibility is handled by adding a body_encoding property, so messages sent by older versions is compatible with this release. However – If you are accessing the messages directly not using Kombu, then you have to respect the body_encoding property.

    If you need to disable base64 encoding then you can do so via the transport options:

               transport_options={'body_encoding': None})

    For transport authors:

    You don’t have to change anything in your custom transports, as this is handled automatically by the base class.

    If you want to use a different encoder you can do so by adding a key to Channel.codecs. Default encoding is specified by the Channel.body_encoding attribute.

    A new codec must provide two methods: encode(data) and decode(data).

  • ConnectionPool/ChannelPool/Resource: Setting limit=None (or 0) now disables pool semantics, and will establish and close the resource whenever acquired or released.

  • ConnectionPool/ChannelPool/Resource: Is now using a LIFO queue instead of the previous FIFO behavior.

    This means that the last resource released will be the one acquired next. I.e. if only a single thread is using the pool this means only a single connection will ever be used.

  • Connection: Cloned connections did not inherit transport_options (__copy__).

  • contrib/requirements is now located in the top directory of the distribution.

  • MongoDB: Now supports authentication using the userid and password arguments to Connection (Issue #30).

  • Connection: Default autentication credentials are now delegated to the individual transports.

    This means that the userid and password arguments to Connection is no longer guest/guest by default.

    The amqplib and pika transports will still have the default credentials.

  • Consumer.__exit__() did not have the correct signature (Issue #32).

  • Channel objects now have a channel_id attribute.

  • MongoDB: Version sniffing broke with development versions of

    mongod (Issue #29).

  • New environment variable KOMBU_LOG_CONNECTION will now emit debug

    log messages for connection related actions.




2011-03-28 05:45 P.M CEST


Ask Solem

  • Now depends on anyjson 0.3.1

    cjson is no longer a recommended json implementation, and anyjson will now emit a deprecation warning if used.

  • Please note that the Pika backend only works with version 0.5.2.

    The latest version (0.9.x) drastically changed API, and it is not compatible yet.

  • on_decode_error is now called for exceptions in message_to_python (Issue #24).

  • Redis: did not respect QoS settings.

  • Redis: Creating a connection now ensures the connection is established.

    This means Connection.ensure_connection works properly with Redis.

  • consumer_tag argument to Queue.consume can’t be None (Issue #21).

    A None value is now automatically converted to empty string. An empty string will make the server generate a unique tag.

  • Connection now supports a transport_options argument.

    This can be used to pass additional arguments to transports.

  • Pika: drain_events raised socket.timeout even if no timeout set (Issue #8).



2011-03-22 04:00 P.M CET


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  • The delivery_mode aliases (persistent/transient) were not automatically converted to integer, and would cause a crash if using the amqplib transport.

  • Redis: The redis-py InvalidData exception suddenly changed name to DataError.

  • The KOMBU_LOG_DEBUG environment variable can now be set to log all channel method calls.

    Support for the following environment variables have been added:

    • KOMBU_LOG_CHANNEL will wrap channels in an object that logs every method call.

    • KOMBU_LOG_DEBUG both enables channel logging and configures the root logger to emit messages to standard error.

    Example Usage:

    $ KOMBU_LOG_DEBUG=1 python
    >>> from kombu import Connection
    >>> conn = Connection()
    >>> channel =
    Start from server, version: 8.0, properties:
        {u'product': 'RabbitMQ',..............  }
    Open OK! known_hosts []
    using channel_id: 1
    Channel open
    >>> channel.queue_declare('myq', passive=True)
    [Kombu channel:1] queue_declare('myq', passive=True)
    (u'myq', 0, 1)



2011-03-17 04:00 P.M CET


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  • Fixed memory leak when creating virtual channels. All virtual transports affected (redis, mongodb, memory, django, sqlalchemy, couchdb, beanstalk).

  • Virtual Transports: Fixed potential race condition when acking messages.

    If you have been affected by this, the error would show itself as an exception raised by the OrderedDict implementation. (object no longer exists).

  • MongoDB transport requires the findandmodify command only available in MongoDB 1.3+, so now raises an exception if connected to an incompatible server version.

  • Virtual Transports: basic.cancel should not try to remove unknown consumer tag.



2011-02-28 04:00 P.M CET


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  • Added Transport.polling_interval

    Used by django-kombu to increase the time to sleep between SELECTs when there are no messages in the queue.

    Users of django-kombu should upgrade to django-kombu v0.9.2.



2011-02-12 04:00 P.M CET


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  • ConnectionPool: Re-connect if amqplib connection closed

  • Adds Queue.as_dict + Exchange.as_dict.

  • Copyright headers updated to include 2011.



2011-01-31 10:45 P.M CET


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  • amqplib: Message properties were not set properly.

  • Ghettoq backend names are now automatically translated to the new names.



2011-01-28 12:00 P.M CET


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  • Redis: Now works with Linux (epoll)



2011-01-27 12:00 P.M CET


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  • Initial release



2010-07-22 04:20 P.M CET


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  • Initial fork of carrot