aiokafka 0.5.2

Kafka integration with asyncio.

asyncio client for Kafka

AIOKafkaProducer

AIOKafkaProducer is a high-level, asynchronous message producer.

Example of AIOKafkaProducer usage:

from aiokafka import AIOKafkaProducer
import asyncio

loop = asyncio.get_event_loop()

async def send_one():
    producer = AIOKafkaProducer(
        loop=loop, bootstrap_servers='localhost:9092')
    # Get cluster layout and initial topic/partition leadership information
    await producer.start()
    try:
        # Produce message
        await producer.send_and_wait("my_topic", b"Super message")
    finally:
        # Wait for all pending messages to be delivered or expire.
        await producer.stop()

loop.run_until_complete(send_one())

AIOKafkaConsumer

AIOKafkaConsumer is a high-level, asynchronous message consumer. It interacts with the assigned Kafka Group Coordinator node to allow multiple consumers to load balance consumption of topics (requires kafka >= 0.9.0.0).

Example of AIOKafkaConsumer usage:

from aiokafka import AIOKafkaConsumer
import asyncio

loop = asyncio.get_event_loop()

async def consume():
    consumer = AIOKafkaConsumer(
        'my_topic', 'my_other_topic',
        loop=loop, bootstrap_servers='localhost:9092',
        group_id="my-group")
    # Get cluster layout and join group `my-group`
    await consumer.start()
    try:
        # Consume messages
        async for msg in consumer:
            print("consumed: ", msg.topic, msg.partition, msg.offset,
                  msg.key, msg.value, msg.timestamp)
    finally:
        # Will leave consumer group; perform autocommit if enabled.
        await consumer.stop()

loop.run_until_complete(consume())

Running tests

Docker is required to run tests. See https://docs.docker.com/engine/installation for installation notes. Also note, that lz4 compression libraries for python will require python-dev package, or python source header files for compilation on Linux. NOTE: You will also need a valid java installation. It’s required for the keytool utility, used to generate ssh keys for some tests.

Setting up tests requirements (assuming you’re within virtualenv on ubuntu 14.04+):

sudo apt-get install -y libsnappy-dev
make setup

Running tests with coverage:

make cov

To run tests with a specific version of Kafka (default one is 1.0.2) use KAFKA_VERSION variable:

make cov KAFKA_VERSION=0.10.2.1

Test running cheatsheat:

• make test FLAGS="-l -x --ff" - run until 1 failure, rerun failed tests fitst. Great for cleaning up a lot of errors, say after a big refactor.
• make test FLAGS="-k consumer" - run only the consumer tests.
• make test FLAGS="-m 'not ssl'" - run tests excluding ssl.
• make test FLAGS="--no-pull" - do not try to pull new docker image before test run.

CHANGES

0.5.2 (2019-03-10)

Bugfixes:

• Fix ConnectionError breaking metadata sync background task (issue #517 and #512)
• Fix event_waiter reference before assignment (pr #504 by @romantolkachyov)
• Bump version of kafka-python

0.5.1 (2019-03-10)

New features:

• Add SASL support with both SASL plain and SASL GGSAPI. Support also includes Broker v0.9.0, but you will need to explicitly pass api_version="0.9". (Big thanks to @cyrbil and @jsurloppe for working on this)
• Added support for max_poll_interval_ms and rebalance_timeout_ms settings ( issue #67)
• Added pause/resume API for AIOKafkaConsumer. (issue #304)
• Added header support to both AIOKafkaConsumer and AIOKafkaProducer for brokers v0.11 and above. (issue #462)

Bugfixes:

• Made sure to not request metadata for all topics if broker version is passed explicitly and is 0.10 and above. (issue #440, thanks to @ulrikjohansson)
• Make sure heartbeat task will close if group is reset. (issue #372)

0.5.0 (2018-12-28)

New features:

• Add full support for V2 format messages with a Cython extension. Those are used for Kafka >= 0.11.0.0
• Added support for transactional producing (issue #182)
• Added support for indempotent producing with enable_idempotence parameter
• Added support for fetch_max_bytes in AIOKafkaConsumer. This can help limit the amount of data transferred in a single roundtrip to broker, which is essential for consumers with large amount of partitions

Bugfixes:

• Fix issue with connections not propagating serialization errors
• Fix issue with group=None resetting offsets on every metadata update (issue #441)
• Fix issue with messages not delivered in order when Leader changes (issue #228)
• Fixed version parsing of api_version parameter. Before it ignored the parameter

0.4.3 (2018-11-01)

Bugfix:

• Fixed memory issue introduced as a result of a bug in asyncio.shield and not cancelling coroutine after usage. (see issue #444 and #436)

0.4.2 (2018-09-12)

Bugfix:

• Added error propagation from coordinator to main consumer. Before consumer just stopped with error logged. (issue #294)
• Fix manual partition assignment, broken in 0.4.0 (issue #394)
• Fixed RecursionError in MessageAccumulator.add_message (issue #409)
• Update kafka-python to latest 1.4.3 and added support for Python3.7
• Dropped support for Python3.3 and Python3.4

Infrastructure:

• Added Kafka 1.0.2 broker for CI test runner
• Refactored travis CI build pipeline

0.4.1 (2018-05-13)

• Fix issue when offset commit error reports wrong partition in log (issue #353)
• Add ResourceWarning when Producer, Consumer or Connections are not closed properly (issue #295)
• Fix Subscription None in GroupCoordinator._do_group_rejoin (issue #306)

0.4.0 (2018-01-30)

Major changes:

• Full refactor of the internals of AIOKafkaConsumer. Needed to avoid several race conditions in code (PR #286, fixes #258, #264 and #261)
• Rewrote Records parsing protocol to allow implementation of newer protocol versions later
• Added C extension for Records parsing protocol, boosting the speed of produce/consume routines significantly
• Added an experimental batch producer API for unique cases, where user want’s to control batching himself (by @shargan)

Minor changes:

• Add timestamp field to produced message’s metadata. This is needed to find LOG_APPEND_TIME configured timestamps.
• Consumer.seek() and similar API’s now raise proper ValueError’s on validation failure instead of AssertionError.

Bug fixes:

• Fix connections_max_idle_ms option, as earlier it was only applied to bootstrap socket. (PR #299)
• Fix consumer.stop() side effect of logging an exception ConsumerStoppedError (issue #263)
• Problem with Producer not able to recover from broker failure (issue #267)
• Traceback containing duplicate entries due to exception sharing (PR #247 by @Artimi)
• Concurrent record consumption rasing InvalidStateError(‘Exception is not set.’) (PR #249 by @aerkert)
• Don’t fail GroupCoordinator._on_join_prepare() if commit_offset() throws exception (PR #230 by @shargan)
• Send session_timeout_ms to GroupCoordinator constructor (PR #229 by @shargan)

Big thanks to:

• @shargan for Producer speed enhancements and the batch produce API proposal/implementation.
• @vineet-rh and other contributors for constant feedback on Consumer problems, leading to the refactor mentioned above.

0.3.1 (2017-09-19)

• Added AIOKafkaProducer.flush() method. (PR #209 by @vineet-rh)

• Fixed a bug with uvloop involving float(“inf”) for timeout. (PR #210 by

  dmitry-moroz)

• Changed test runner to allow running tests on OSX. (PR #213 by @shargan)

0.3.0 (2017-08-17)

• Moved all public structures and errors to aiokafka namespace. You will no longer need to import from kafka namespace.
• Changed ConsumerRebalanceListener to support either function or coroutine for on_partitions_assigned and on_partitions_revoked callbacks. (PR #190 by @ask)
• Added support for offsets_for_times, beginning_offsets, end_offsets API’s. (issue #164)
• Coordinator requests are now sent using a separate socket. Fixes slow commit issue. (issuer #137, issue #128)
• Added seek_to_end, seek_to_beginning API’s. (issue #154)
• Updated documentation to provide more useful usage guide on both Consumer and Producer interface.

0.2.3 (2017-07-23)

• Fixed retry problem in Producer, when buffer is not reset to 0 offset. Thanks to @ngavrysh for the fix in Tubular/aiokafka fork. (issue #184)
• Fixed how Producer handles retries on Leader node failure. It just did not work before… Thanks to @blugowski for the help in locating the problem. (issue #176, issue #173)
• Fixed degrade in v0.2.2 on Consumer with no group_id. (issue #166)

0.2.2 (2017-04-17)

• Reconnect after KafkaTimeoutException. (PR #149 by @Artimi)
• Fixed compacted topic handling. It could skip messages if those were compacted (issue #71)
• Fixed old issue with new topics not adding to subscription on pattern (issue #46)
• Another fix for Consumer race condition on JoinGroup. This forces Leader to wait for new metadata before assigning partitions. (issue #118)
• Changed metadata listener in Coordinator to avoid 2 rejoins in a rare condition (issue #108)
• getmany will not return 0 results until we hit timeout. (issue #117)

Big thanks to @Artimi for pointing out several of those issues.

0.2.1 (2017-02-19)

• Add a check to wait topic autocreation in Consumer, instead of raising UnknownTopicOrPartitionError (PR #92 by fabregas)
• Consumer now stops consumption after consumer.stop() call. Any new get* calls will result in ConsumerStoppedError (PR #81)
• Added exclude_internal_topics option for Consumer (PR #111)
• Better support for pattern subscription when used with group_id (part of PR #111)
• Fix for Consumer subscribe and JoinGroup race condition (issue #88). Coordinator will now notice subscription changes during rebalance and will join group again. (PR #106)
• Changed logging messages according to KAFKA-3318. Now INFO level should be less messy and more informative. (PR #110)
• Add support for connections_max_idle_ms config (PR #113)

0.2.0 (2016-12-18)

• Added SSL support. (PR #81 by Drizzt1991)
• Fixed UnknownTopicOrPartitionError error on first message for autocreated topic (PR #96 by fabregas)
• Fixed next_record recursion (PR #94 by fabregas)
• Fixed Heartbeat fail if no consumers (PR #92 by fabregas)
• Added docs addressing kafka-python and aiokafka differences (PR #70 by Drizzt1991)
• Added max_poll_records option for Consumer (PR #72 by Drizzt1991)
• Fix kafka-python typos in docs (PR #69 by jeffwidman)
• Topics and partitions are now randomized on each Fetch request (PR #66 by Drizzt1991)

0.1.4 (2016-11-07)

• Bumped kafka-python version to 1.3.1 and Kafka to 0.10.1.0.
• Fixed auto version detection, to correctly handle 0.10.0.0 version
• Updated Fetch and Produce requests to use v2 with v0.10.0 message format on brokers. This allows a timestamp to be associated with messages.
• Changed lz4 compression framing, as it was changed due to KIP-57 in new message format.
• Minor refactorings

Big thanks to @fabregas for the hard work on this release (PR #60)

0.1.3 (2016-10-18)

• Fixed bug with infinite loop on heartbeats with autocommit=True. #44
• Bumped kafka-python to version 1.1.1
• Fixed docker test runner with multiple interfaces
• Minor documentation fixes

0.1.2 (2016-04-30)

• Added Python3.5 usage example to docs
• Don’t raise retriable exceptions in 3.5’s async for iterator
• Fix Cancellation issue with producer’s send_and_wait method

0.1.1 (2016-04-15)

• Fix packaging issues. Removed unneded files from package.

0.1.0 (2016-04-15)

Initial release

Added full support for Kafka 9.0. Older Kafka versions are not tested.