import asyncio
import logging
import sys
import traceback
import warnings
from kafka.partitioner.default import DefaultPartitioner
from kafka.codec import has_gzip, has_snappy, has_lz4, has_zstd
from aiokafka.client import AIOKafkaClient
from aiokafka.errors import (
MessageSizeTooLargeError, UnsupportedVersionError, IllegalOperation)
from aiokafka.record.default_records import DefaultRecordBatch
from aiokafka.record.legacy_records import LegacyRecordBatchBuilder
from aiokafka.structs import TopicPartition
from aiokafka.util import (
INTEGER_MAX_VALUE, commit_structure_validate, create_task, get_running_loop
)
from .message_accumulator import MessageAccumulator
from .sender import Sender
from .transaction_manager import TransactionManager
log = logging.getLogger(__name__)
_missing = object()
[docs]class AIOKafkaProducer:
"""A Kafka client that publishes records to the Kafka cluster.
The producer consists of a pool of buffer space that holds records that
haven't yet been transmitted to the server as well as a background task
that is responsible for turning these records into requests and
transmitting them to the cluster.
The :meth:`send` method is asynchronous. When called it adds the record to a
buffer of pending record sends and immediately returns. This allows the
producer to batch together individual records for efficiency.
The `acks` config controls the criteria under which requests are considered
complete. The ``all`` setting will result in waiting for all replicas to
respond, the slowest but most durable setting.
The `key_serializer` and `value_serializer` instruct how to turn the key and
value objects the user provides into :class:`bytes`.
Arguments:
bootstrap_servers (str, list(str)): a ``host[:port]`` string or list of
``host[:port]`` strings that the producer should contact to
bootstrap initial cluster metadata. This does not have to be the
full node list. It just needs to have at least one broker that will
respond to a Metadata API Request. Default port is 9092. If no
servers are specified, will default to ``localhost:9092``.
client_id (str): a name for this client. This string is passed in
each request to servers and can be used to identify specific
server-side log entries that correspond to this client.
Default: ``aiokafka-producer-#`` (appended with a unique number
per instance)
key_serializer (Callable): used to convert user-supplied keys to bytes
If not :data:`None`, called as ``f(key),`` should return
:class:`bytes`.
Default: :data:`None`.
value_serializer (Callable): used to convert user-supplied message
values to :class:`bytes`. If not :data:`None`, called as
``f(value)``, should return :class:`bytes`.
Default: :data:`None`.
acks (Any): one of ``0``, ``1``, ``all``. The number of acknowledgments
the producer requires the leader to have received before considering a
request complete. This controls the durability of records that are
sent. The following settings are common:
* ``0``: Producer will not wait for any acknowledgment from the server
at all. The message will immediately be added to the socket
buffer and considered sent. No guarantee can be made that the
server has received the record in this case, and the retries
configuration will not take effect (as the client won't
generally know of any failures). The offset given back for each
record will always be set to -1.
* ``1``: The broker leader will write the record to its local log but
will respond without awaiting full acknowledgement from all
followers. In this case should the leader fail immediately
after acknowledging the record but before the followers have
replicated it then the record will be lost.
* ``all``: The broker leader will wait for the full set of in-sync
replicas to acknowledge the record. This guarantees that the
record will not be lost as long as at least one in-sync replica
remains alive. This is the strongest available guarantee.
If unset, defaults to ``acks=1``. If `enable_idempotence` is
:data:`True` defaults to ``acks=all``
compression_type (str): The compression type for all data generated by
the producer. Valid values are ``gzip``, ``snappy``, ``lz4``, ``zstd``
or :data:`None`.
Compression is of full batches of data, so the efficacy of batching
will also impact the compression ratio (more batching means better
compression). Default: :data:`None`.
max_batch_size (int): Maximum size of buffered data per partition.
After this amount :meth:`send` coroutine will block until batch is
drained.
Default: 16384
linger_ms (int): The producer groups together any records that arrive
in between request transmissions into a single batched request.
Normally this occurs only under load when records arrive faster
than they can be sent out. However in some circumstances the client
may want to reduce the number of requests even under moderate load.
This setting accomplishes this by adding a small amount of
artificial delay; that is, if first request is processed faster,
than `linger_ms`, producer will wait ``linger_ms - process_time``.
Default: 0 (i.e. no delay).
partitioner (Callable): Callable used to determine which partition
each message is assigned to. Called (after key serialization):
``partitioner(key_bytes, all_partitions, available_partitions)``.
The default partitioner implementation hashes each non-None key
using the same murmur2 algorithm as the Java client so that
messages with the same key are assigned to the same partition.
When a key is :data:`None`, the message is delivered to a random partition
(filtered to partitions with available leaders only, if possible).
max_request_size (int): The maximum size of a request. This is also
effectively a cap on the maximum record size. Note that the server
has its own cap on record size which may be different from this.
This setting will limit the number of record batches the producer
will send in a single request to avoid sending huge requests.
Default: 1048576.
metadata_max_age_ms (int): The period of time in milliseconds after
which we force a refresh of metadata even if we haven't seen any
partition leadership changes to proactively discover any new
brokers or partitions. Default: 300000
request_timeout_ms (int): Produce request timeout in milliseconds.
As it's sent as part of
:class:`~kafka.protocol.produce.ProduceRequest` (it's a blocking
call), maximum waiting time can be up to ``2 *
request_timeout_ms``.
Default: 40000.
retry_backoff_ms (int): Milliseconds to backoff when retrying on
errors. Default: 100.
api_version (str): specify which kafka API version to use.
If set to ``auto``, will attempt to infer the broker version by
probing various APIs. Default: ``auto``
security_protocol (str): Protocol used to communicate with brokers.
Valid values are: ``PLAINTEXT``, ``SSL``. Default: ``PLAINTEXT``.
Default: ``PLAINTEXT``.
ssl_context (ssl.SSLContext): pre-configured :class:`~ssl.SSLContext`
for wrapping socket connections. Directly passed into asyncio's
:meth:`~asyncio.loop.create_connection`. For more
information see :ref:`ssl_auth`.
Default: :data:`None`
connections_max_idle_ms (int): Close idle connections after the number
of milliseconds specified by this config. Specifying :data:`None` will
disable idle checks. Default: 540000 (9 minutes).
enable_idempotence (bool): When set to :data:`True`, the producer will
ensure that exactly one copy of each message is written in the
stream. If :data:`False`, producer retries due to broker failures,
etc., may write duplicates of the retried message in the stream.
Note that enabling idempotence acks to set to ``all``. If it is not
explicitly set by the user it will be chosen. If incompatible
values are set, a :exc:`ValueError` will be thrown.
New in version 0.5.0.
sasl_mechanism (str): Authentication mechanism when security_protocol
is configured for ``SASL_PLAINTEXT`` or ``SASL_SSL``. Valid values
are: ``PLAIN``, ``GSSAPI``, ``SCRAM-SHA-256``, ``SCRAM-SHA-512``,
``OAUTHBEARER``.
Default: ``PLAIN``
sasl_plain_username (str): username for SASL ``PLAIN`` authentication.
Default: :data:`None`
sasl_plain_password (str): password for SASL ``PLAIN`` authentication.
Default: :data:`None`
sasl_oauth_token_provider (:class:`~aiokafka.abc.AbstractTokenProvider`):
OAuthBearer token provider instance. (See
:mod:`kafka.oauth.abstract`).
Default: :data:`None`
Note:
Many configuration parameters are taken from the Java client:
https://kafka.apache.org/documentation.html#producerconfigs
"""
_PRODUCER_CLIENT_ID_SEQUENCE = 0
_COMPRESSORS = {
'gzip': (has_gzip, DefaultRecordBatch.CODEC_GZIP),
'snappy': (has_snappy, DefaultRecordBatch.CODEC_SNAPPY),
'lz4': (has_lz4, DefaultRecordBatch.CODEC_LZ4),
'zstd': (has_zstd, DefaultRecordBatch.CODEC_ZSTD),
}
_closed = None # Serves as an uninitialized flag for __del__
_source_traceback = None
def __init__(self, *, loop=None, bootstrap_servers='localhost',
client_id=None,
metadata_max_age_ms=300000, request_timeout_ms=40000,
api_version='auto', acks=_missing,
key_serializer=None, value_serializer=None,
compression_type=None, max_batch_size=16384,
partitioner=DefaultPartitioner(), max_request_size=1048576,
linger_ms=0, send_backoff_ms=100,
retry_backoff_ms=100, security_protocol="PLAINTEXT",
ssl_context=None, connections_max_idle_ms=540000,
enable_idempotence=False, transactional_id=None,
transaction_timeout_ms=60000, sasl_mechanism="PLAIN",
sasl_plain_password=None, sasl_plain_username=None,
sasl_kerberos_service_name='kafka',
sasl_kerberos_domain_name=None,
sasl_oauth_token_provider=None):
if loop is None:
loop = get_running_loop()
else:
warnings.warn("The loop argument is deprecated since 0.7.1, "
"and scheduled for removal in 0.8.0",
DeprecationWarning, stacklevel=2)
if loop.get_debug():
self._source_traceback = traceback.extract_stack(sys._getframe(1))
self._loop = loop
if acks not in (0, 1, -1, 'all', _missing):
raise ValueError("Invalid ACKS parameter")
if compression_type not in ('gzip', 'snappy', 'lz4', 'zstd', None):
raise ValueError("Invalid compression type!")
if compression_type:
checker, compression_attrs = self._COMPRESSORS[compression_type]
if not checker():
raise RuntimeError("Compression library for {} not found"
.format(compression_type))
else:
compression_attrs = 0
if transactional_id is not None:
enable_idempotence = True
else:
transaction_timeout_ms = INTEGER_MAX_VALUE
if enable_idempotence:
if acks is _missing:
acks = -1
elif acks not in ('all', -1):
raise ValueError(
"acks={} not supported if enable_idempotence=True"
.format(acks))
self._txn_manager = TransactionManager(
transactional_id, transaction_timeout_ms)
else:
self._txn_manager = None
if acks is _missing:
acks = 1
elif acks == 'all':
acks = -1
AIOKafkaProducer._PRODUCER_CLIENT_ID_SEQUENCE += 1
if client_id is None:
client_id = 'aiokafka-producer-%s' % \
AIOKafkaProducer._PRODUCER_CLIENT_ID_SEQUENCE
self._key_serializer = key_serializer
self._value_serializer = value_serializer
self._compression_type = compression_type
self._partitioner = partitioner
self._max_request_size = max_request_size
self._request_timeout_ms = request_timeout_ms
self.client = AIOKafkaClient(
loop=loop, bootstrap_servers=bootstrap_servers,
client_id=client_id, metadata_max_age_ms=metadata_max_age_ms,
request_timeout_ms=request_timeout_ms,
retry_backoff_ms=retry_backoff_ms,
api_version=api_version, security_protocol=security_protocol,
ssl_context=ssl_context,
connections_max_idle_ms=connections_max_idle_ms,
sasl_mechanism=sasl_mechanism,
sasl_plain_username=sasl_plain_username,
sasl_plain_password=sasl_plain_password,
sasl_kerberos_service_name=sasl_kerberos_service_name,
sasl_kerberos_domain_name=sasl_kerberos_domain_name,
sasl_oauth_token_provider=sasl_oauth_token_provider)
self._metadata = self.client.cluster
self._message_accumulator = MessageAccumulator(
self._metadata, max_batch_size, compression_attrs,
self._request_timeout_ms / 1000, txn_manager=self._txn_manager,
loop=loop)
self._sender = Sender(
self.client, acks=acks, txn_manager=self._txn_manager,
retry_backoff_ms=retry_backoff_ms, linger_ms=linger_ms,
message_accumulator=self._message_accumulator,
request_timeout_ms=request_timeout_ms)
self._closed = False
# Warn if producer was not closed properly
# We don't attempt to close the Consumer, as __del__ is synchronous
def __del__(self, _warnings=warnings):
if self._closed is False:
_warnings.warn(f"Unclosed AIOKafkaProducer {self!r}",
ResourceWarning,
source=self)
context = {'producer': self,
'message': 'Unclosed AIOKafkaProducer'}
if self._source_traceback is not None:
context['source_traceback'] = self._source_traceback
self._loop.call_exception_handler(context)
[docs] async def start(self):
"""Connect to Kafka cluster and check server version"""
assert self._loop is get_running_loop(), (
"Please create objects with the same loop as running with"
)
log.debug("Starting the Kafka producer") # trace
await self.client.bootstrap()
if self._compression_type == 'lz4':
assert self.client.api_version >= (0, 8, 2), \
'LZ4 Requires >= Kafka 0.8.2 Brokers'
elif self._compression_type == 'zstd':
assert self.client.api_version >= (2, 1, 0), \
'Zstd Requires >= Kafka 2.1.0 Brokers'
if self._txn_manager is not None and self.client.api_version < (0, 11):
raise UnsupportedVersionError(
"Idempotent producer available only for Broker version 0.11"
" and above")
await self._sender.start()
self._message_accumulator.set_api_version(self.client.api_version)
self._producer_magic = 0 if self.client.api_version < (0, 10) else 1
log.debug("Kafka producer started")
[docs] async def flush(self):
"""Wait until all batches are Delivered and futures resolved"""
await self._message_accumulator.flush()
[docs] async def stop(self):
"""Flush all pending data and close all connections to kafka cluster"""
if self._closed:
return
self._closed = True
# If the sender task is down there is no way for accumulator to flush
if self._sender is not None and self._sender.sender_task is not None:
await asyncio.wait([
create_task(self._message_accumulator.close()),
self._sender.sender_task],
return_when=asyncio.FIRST_COMPLETED)
await self._sender.close()
await self.client.close()
log.debug("The Kafka producer has closed.")
[docs] async def partitions_for(self, topic):
"""Returns set of all known partitions for the topic."""
return (await self.client._wait_on_metadata(topic))
def _serialize(self, topic, key, value):
if self._key_serializer:
serialized_key = self._key_serializer(key)
else:
serialized_key = key
if self._value_serializer:
serialized_value = self._value_serializer(value)
else:
serialized_value = value
message_size = LegacyRecordBatchBuilder.record_overhead(
self._producer_magic)
if serialized_key is not None:
message_size += len(serialized_key)
if serialized_value is not None:
message_size += len(serialized_value)
if message_size > self._max_request_size:
raise MessageSizeTooLargeError(
"The message is %d bytes when serialized which is larger than"
" the maximum request size you have configured with the"
" max_request_size configuration" % message_size)
return serialized_key, serialized_value
def _partition(self, topic, partition, key, value,
serialized_key, serialized_value):
if partition is not None:
assert partition >= 0
assert partition in self._metadata.partitions_for_topic(topic), \
'Unrecognized partition'
return partition
all_partitions = list(self._metadata.partitions_for_topic(topic))
available = list(self._metadata.available_partitions_for_topic(topic))
return self._partitioner(
serialized_key, all_partitions, available)
[docs] async def send(
self, topic, value=None, key=None, partition=None,
timestamp_ms=None, headers=None
):
"""Publish a message to a topic.
Arguments:
topic (str): topic where the message will be published
value (Optional): message value. Must be type :class:`bytes`, or be
serializable to :class:`bytes` via configured `value_serializer`. If
value is :data:`None`, key is required and message acts as a
``delete``.
See `Kafka compaction documentation
<https://kafka.apache.org/documentation.html#compaction>`__ for
more details. (compaction requires kafka >= 0.8.1)
partition (int, Optional): optionally specify a partition. If not
set, the partition will be selected using the configured
`partitioner`.
key (Optional): a key to associate with the message. Can be used to
determine which partition to send the message to. If partition
is :data:`None` (and producer's partitioner config is left as default),
then messages with the same key will be delivered to the same
partition (but if key is :data:`None`, partition is chosen randomly).
Must be type :class:`bytes`, or be serializable to bytes via configured
`key_serializer`.
timestamp_ms (int, Optional): epoch milliseconds (from Jan 1 1970
UTC) to use as the message timestamp. Defaults to current time.
headers (Optional): Kafka headers to be included in the message using
the format ``[("key", b"value")]``. Iterable of tuples where key
is a normal string and value is a byte string.
Returns:
asyncio.Future: object that will be set when message is
processed
Raises:
~aiokafka.errors.KafkaTimeoutError: if we can't schedule this record
(pending buffer is full) in up to `request_timeout_ms`
milliseconds.
Note:
The returned future will wait based on `request_timeout_ms`
setting. Cancelling the returned future **will not** stop event
from being sent, but cancelling the :meth:`send` coroutine itself
**will**.
"""
assert value is not None or self.client.api_version >= (0, 8, 1), (
'Null messages require kafka >= 0.8.1')
assert not (value is None and key is None), \
'Need at least one: key or value'
# first make sure the metadata for the topic is available
await self.client._wait_on_metadata(topic)
# Ensure transaction is started and not committing
if self._txn_manager is not None:
txn_manager = self._txn_manager
if txn_manager.transactional_id is not None and \
not self._txn_manager.is_in_transaction():
raise IllegalOperation(
"Can't send messages while not in transaction")
if headers is not None:
if self.client.api_version < (0, 11):
raise UnsupportedVersionError(
"Headers not supported before Kafka 0.11")
else:
# Record parser/builder support only list type, no explicit None
headers = []
key_bytes, value_bytes = self._serialize(topic, key, value)
partition = self._partition(topic, partition, key, value,
key_bytes, value_bytes)
tp = TopicPartition(topic, partition)
log.debug("Sending (key=%s value=%s) to %s", key, value, tp)
fut = await self._message_accumulator.add_message(
tp, key_bytes, value_bytes, self._request_timeout_ms / 1000,
timestamp_ms=timestamp_ms, headers=headers)
return fut
[docs] async def send_and_wait(
self, topic, value=None, key=None, partition=None,
timestamp_ms=None, headers=None
):
"""Publish a message to a topic and wait the result"""
future = await self.send(
topic, value, key, partition, timestamp_ms, headers)
return (await future)
[docs] def create_batch(self):
"""Create and return an empty :class:`.BatchBuilder`.
The batch is not queued for send until submission to :meth:`send_batch`.
Returns:
BatchBuilder: empty batch to be filled and submitted by the caller.
"""
return self._message_accumulator.create_builder()
[docs] async def send_batch(self, batch, topic, *, partition):
"""Submit a BatchBuilder for publication.
Arguments:
batch (BatchBuilder): batch object to be published.
topic (str): topic where the batch will be published.
partition (int): partition where this batch will be published.
Returns:
asyncio.Future: object that will be set when the batch is
delivered.
"""
# first make sure the metadata for the topic is available
await self.client._wait_on_metadata(topic)
# We only validate we have the partition in the metadata here
partition = self._partition(topic, partition, None, None, None, None)
# Ensure transaction is started and not committing
if self._txn_manager is not None:
txn_manager = self._txn_manager
if txn_manager.transactional_id is not None and \
not self._txn_manager.is_in_transaction():
raise IllegalOperation(
"Can't send messages while not in transaction")
tp = TopicPartition(topic, partition)
log.debug("Sending batch to %s", tp)
future = await self._message_accumulator.add_batch(
batch, tp, self._request_timeout_ms / 1000)
return future
def _ensure_transactional(self):
if self._txn_manager is None or \
self._txn_manager.transactional_id is None:
raise IllegalOperation(
"You need to configure transaction_id to use transactions")
async def begin_transaction(self):
self._ensure_transactional()
log.debug(
"Beginning a new transaction for id %s",
self._txn_manager.transactional_id)
await asyncio.shield(
self._txn_manager.wait_for_pid()
)
self._txn_manager.begin_transaction()
async def commit_transaction(self):
self._ensure_transactional()
log.debug(
"Committing transaction for id %s",
self._txn_manager.transactional_id)
self._txn_manager.committing_transaction()
await asyncio.shield(
self._txn_manager.wait_for_transaction_end(),
)
async def abort_transaction(self):
self._ensure_transactional()
log.debug(
"Aborting transaction for id %s",
self._txn_manager.transactional_id)
self._txn_manager.aborting_transaction()
await asyncio.shield(
self._txn_manager.wait_for_transaction_end(),
)
[docs] def transaction(self):
"""Start a transaction context"""
return TransactionContext(self)
async def send_offsets_to_transaction(self, offsets, group_id):
self._ensure_transactional()
if not self._txn_manager.is_in_transaction():
raise IllegalOperation("Not in the middle of a transaction")
if not group_id or not isinstance(group_id, str):
raise ValueError(group_id)
# validate `offsets` structure
formatted_offsets = commit_structure_validate(offsets)
log.debug(
"Begin adding offsets %s for consumer group %s to transaction",
formatted_offsets, group_id)
fut = self._txn_manager.add_offsets_to_txn(formatted_offsets, group_id)
await asyncio.shield(fut)
async def __aenter__(self):
await self.start()
return self
async def __aexit__(self, exc_type, exc, tb):
await self.stop()
class TransactionContext:
def __init__(self, producer):
self._producer = producer
async def __aenter__(self):
await self._producer.begin_transaction()
return self
async def __aexit__(self, exc_type, exc_value, traceback):
if exc_type is not None:
# If called directly we want the API to raise a InvalidState error,
# but when exiting a context manager we should just let it out
if self._producer._txn_manager.is_fatal_error():
return
await self._producer.abort_transaction()
else:
await self._producer.commit_transaction()
