aiokafka 0.4.0

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.

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

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

Running tests:

make cov

To run tests with a specific version of Kafka (default one is 0.10.1.0) use KAFKA_VERSION variable:

make cov KAFKA_VERSION=0.10.0.0

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

0.4.0 (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.