Module pulsar
The Pulsar Python client library is based on the existing C++ client library. All the same features are exposed through the Python interface.
Currently, the only supported Python version is 2.7.
Install from PyPI
Download Python wheel binary files for MacOS and Linux directly from the PyPI archive.
#!shell
$ sudo pip install pulsar-client
Install from sources
Follow the instructions to compile the Pulsar C++ client library. This method will also build the Python binding for the library.
To install the Python bindings:
#!shell
$ cd pulsar-client-cpp/python
$ sudo python setup.py install
Examples
Producer example
#!python
import pulsar
client = pulsar.Client('pulsar://localhost:6650')
producer = client.create_producer('my-topic')
for i in range(10):
producer.send(('Hello-%d' % i).encode('utf-8'))
client.close()
Consumer Example
#!python
import pulsar
client = pulsar.Client('pulsar://localhost:6650')
consumer = client.subscribe('my-topic', 'my-subscription')
while True:
msg = consumer.receive()
print("Received message '%s' id='%s'", msg.data().decode('utf-8'), msg.message_id())
consumer.acknowledge(msg)
client.close()
Async producer example
#!python
import pulsar
client = pulsar.Client('pulsar://localhost:6650')
producer = client.create_producer(
'my-topic',
block_if_queue_full=True,
batching_enabled=True,
batching_max_publish_delay_ms=10
)
def send_callback(res, msg):
print('Message published res=%s', res)
while True:
producer.send_async(('Hello-%d' % i).encode('utf-8'), send_callback)
client.close()
Expand source code
#
# Licensed to the Apache Software Foundation (ASF) under one
# or more contributor license agreements. See the NOTICE file
# distributed with this work for additional information
# regarding copyright ownership. The ASF licenses this file
# to you under the Apache License, Version 2.0 (the
# "License"); you may not use this file except in compliance
# with the License. You may obtain a copy of the License at
#
# http://www.apache.org/licenses/LICENSE-2.0
#
# Unless required by applicable law or agreed to in writing,
# software distributed under the License is distributed on an
# "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY
# KIND, either express or implied. See the License for the
# specific language governing permissions and limitations
# under the License.
#
"""
The Pulsar Python client library is based on the existing C++ client library.
All the same features are exposed through the Python interface.
Currently, the only supported Python version is 2.7.
## Install from PyPI
Download Python wheel binary files for MacOS and Linux
directly from the PyPI archive.
#!shell
$ sudo pip install pulsar-client
## Install from sources
Follow the instructions to compile the Pulsar C++ client library. This method
will also build the Python binding for the library.
To install the Python bindings:
#!shell
$ cd pulsar-client-cpp/python
$ sudo python setup.py install
## Examples
### [Producer](#pulsar.Producer) example
#!python
import pulsar
client = pulsar.Client('pulsar://localhost:6650')
producer = client.create_producer('my-topic')
for i in range(10):
producer.send(('Hello-%d' % i).encode('utf-8'))
client.close()
#### [Consumer](#pulsar.Consumer) Example
#!python
import pulsar
client = pulsar.Client('pulsar://localhost:6650')
consumer = client.subscribe('my-topic', 'my-subscription')
while True:
msg = consumer.receive()
print("Received message '%s' id='%s'", msg.data().decode('utf-8'), msg.message_id())
consumer.acknowledge(msg)
client.close()
### [Async producer](#pulsar.Producer.send_async) example
#!python
import pulsar
client = pulsar.Client('pulsar://localhost:6650')
producer = client.create_producer(
'my-topic',
block_if_queue_full=True,
batching_enabled=True,
batching_max_publish_delay_ms=10
)
def send_callback(res, msg):
print('Message published res=%s', res)
while True:
producer.send_async(('Hello-%d' % i).encode('utf-8'), send_callback)
client.close()
"""
import _pulsar
from _pulsar import Result, CompressionType, ConsumerType, PartitionsRoutingMode # noqa: F401
from pulsar.functions.function import Function
from pulsar.functions.context import Context
from pulsar.functions.serde import SerDe, IdentitySerDe, PickleSerDe
import re
_retype = type(re.compile('x'))
class MessageId:
"""
Represents a message id
"""
'Represents the earliest message stored in a topic'
earliest = _pulsar.MessageId.earliest
'Represents the latest message published on a topic'
latest = _pulsar.MessageId.latest
def serialize(self):
"""
Returns a bytes representation of the message id.
This bytes sequence can be stored and later deserialized.
"""
return self._msg_id.serialize()
@staticmethod
def deserialize(message_id_bytes):
"""
Deserialize a message id object from a previously
serialized bytes sequence.
"""
return _pulsar.MessageId.deserialize(message_id_bytes)
class Message:
"""
Message objects are returned by a consumer, either by calling `receive` or
through a listener.
"""
def data(self):
"""
Returns object typed bytes with the content of the message.
"""
return self._message.data()
def properties(self):
"""
Return the properties attached to the message. Properties are
application-defined key/value pairs that will be attached to the
message.
"""
return self._message.properties()
def partition_key(self):
"""
Get the partitioning key for the message.
"""
return self._message.partition_key()
def publish_timestamp(self):
"""
Get the timestamp in milliseconds with the message publish time.
"""
return self._message.publish_timestamp()
def message_id(self):
"""
The message ID that can be used to refere to this particular message.
"""
return self._message.message_id()
class Authentication:
"""
Authentication provider object. Used to load authentication from an external
shared library.
"""
def __init__(self, dynamicLibPath, authParamsString):
"""
Create the authentication provider instance.
**Args**
* `dynamicLibPath`: Path to the authentication provider shared library
(such as `tls.so`)
* `authParamsString`: Comma-separated list of provider-specific
configuration params
"""
_check_type(str, dynamicLibPath, 'dynamicLibPath')
_check_type(str, authParamsString, 'authParamsString')
self.auth = _pulsar.Authentication(dynamicLibPath, authParamsString)
class AuthenticationTLS(Authentication):
"""
TLS Authentication implementation
"""
def __init__(self, certificate_path, private_key_path):
"""
Create the TLS authentication provider instance.
**Args**
* `certificatePath`: Path to the public certificate
* `privateKeyPath`: Path to private TLS key
"""
_check_type(str, certificate_path, 'certificate_path')
_check_type(str, private_key_path, 'private_key_path')
self.auth = _pulsar.AuthenticationTLS(certificate_path, private_key_path)
class AuthenticationAthenz(Authentication):
"""
Athenz Authentication implementation
"""
def __init__(self, auth_params_string):
"""
Create the Athenz authentication provider instance.
**Args**
* `auth_params_string`: JSON encoded configuration for Athenz client
"""
_check_type(str, auth_params_string, 'auth_params_string')
self.auth = _pulsar.AuthenticationAthenz(auth_params_string)
class Client:
"""
The Pulsar client. A single client instance can be used to create producers
and consumers on multiple topics.
The client will share the same connection pool and threads across all
producers and consumers.
"""
def __init__(self, service_url,
authentication=None,
operation_timeout_seconds=30,
io_threads=1,
message_listener_threads=1,
concurrent_lookup_requests=50000,
log_conf_file_path=None,
use_tls=False,
tls_trust_certs_file_path=None,
tls_allow_insecure_connection=False
):
"""
Create a new Pulsar client instance.
**Args**
* `service_url`: The Pulsar service url eg: pulsar://my-broker.com:6650/
**Options**
* `authentication`:
Set the authentication provider to be used with the broker. For example:
`AuthenticationTls` or `AuthenticationAthenz`
* `operation_timeout_seconds`:
Set timeout on client operations (subscribe, create producer, close,
unsubscribe).
* `io_threads`:
Set the number of IO threads to be used by the Pulsar client.
* `message_listener_threads`:
Set the number of threads to be used by the Pulsar client when
delivering messages through message listener. The default is 1 thread
per Pulsar client. If using more than 1 thread, messages for distinct
`message_listener`s will be delivered in different threads, however a
single `MessageListener` will always be assigned to the same thread.
* `concurrent_lookup_requests`:
Number of concurrent lookup-requests allowed on each broker connection
to prevent overload on the broker.
* `log_conf_file_path`:
Initialize log4cxx from a configuration file.
* `use_tls`:
Configure whether to use TLS encryption on the connection. This setting
is deprecated. TLS will be automatically enabled if the `serviceUrl` is
set to `pulsar+ssl://` or `https://`
* `tls_trust_certs_file_path`:
Set the path to the trusted TLS certificate file.
* `tls_allow_insecure_connection`:
Configure whether the Pulsar client accepts untrusted TLS certificates
from the broker.
"""
_check_type(str, service_url, 'service_url')
_check_type_or_none(Authentication, authentication, 'authentication')
_check_type(int, operation_timeout_seconds, 'operation_timeout_seconds')
_check_type(int, io_threads, 'io_threads')
_check_type(int, message_listener_threads, 'message_listener_threads')
_check_type(int, concurrent_lookup_requests, 'concurrent_lookup_requests')
_check_type_or_none(str, log_conf_file_path, 'log_conf_file_path')
_check_type(bool, use_tls, 'use_tls')
_check_type_or_none(str, tls_trust_certs_file_path, 'tls_trust_certs_file_path')
_check_type(bool, tls_allow_insecure_connection, 'tls_allow_insecure_connection')
conf = _pulsar.ClientConfiguration()
if authentication:
conf.authentication(authentication.auth)
conf.operation_timeout_seconds(operation_timeout_seconds)
conf.io_threads(io_threads)
conf.message_listener_threads(message_listener_threads)
conf.concurrent_lookup_requests(concurrent_lookup_requests)
if log_conf_file_path:
conf.log_conf_file_path(log_conf_file_path)
if use_tls or service_url.startswith('pulsar+ssl://') or service_url.startswith('https://'):
conf.use_tls(True)
if tls_trust_certs_file_path:
conf.tls_trust_certs_file_path(tls_trust_certs_file_path)
conf.tls_allow_insecure_connection(tls_allow_insecure_connection)
self._client = _pulsar.Client(service_url, conf)
self._consumers = []
def create_producer(self, topic,
producer_name=None,
initial_sequence_id=None,
send_timeout_millis=30000,
compression_type=CompressionType.NONE,
max_pending_messages=1000,
max_pending_messages_across_partitions=50000,
block_if_queue_full=False,
batching_enabled=False,
batching_max_messages=1000,
batching_max_allowed_size_in_bytes=128*1024,
batching_max_publish_delay_ms=10,
message_routing_mode=PartitionsRoutingMode.RoundRobinDistribution,
properties=None,
):
"""
Create a new producer on a given topic.
**Args**
* `topic`:
The topic name
**Options**
* `producer_name`:
Specify a name for the producer. If not assigned,
the system will generate a globally unique name which can be accessed
with `Producer.producer_name()`. When specifying a name, it is app to
the user to ensure that, for a given topic, the producer name is unique
across all Pulsar's clusters.
* `initial_sequence_id`:
Set the baseline for the sequence ids for messages
published by the producer. First message will be using
`(initialSequenceId + 1)`` as its sequence id and subsequent messages will
be assigned incremental sequence ids, if not otherwise specified.
* `send_timeout_seconds`:
If a message is not acknowledged by the server before the
`send_timeout` expires, an error will be reported.
* `compression_type`:
Set the compression type for the producer. By default, message
payloads are not compressed. Supported compression types are
`CompressionType.LZ4` and `CompressionType.ZLib`.
* `max_pending_messages`:
Set the max size of the queue holding the messages pending to receive
an acknowledgment from the broker.
* `max_pending_messages_across_partitions`:
Set the max size of the queue holding the messages pending to receive
an acknowledgment across partitions from the broker.
* `block_if_queue_full`: Set whether `send_async` operations should
block when the outgoing message queue is full.
* `message_routing_mode`:
Set the message routing mode for the partitioned producer. Default is `PartitionsRoutingMode.RoundRobinDistribution`,
other option is `PartitionsRoutingMode.UseSinglePartition`
* `properties`:
Sets the properties for the producer. The properties associated with a producer
can be used for identify a producer at broker side.
"""
_check_type(str, topic, 'topic')
_check_type_or_none(str, producer_name, 'producer_name')
_check_type_or_none(int, initial_sequence_id, 'initial_sequence_id')
_check_type(int, send_timeout_millis, 'send_timeout_millis')
_check_type(CompressionType, compression_type, 'compression_type')
_check_type(int, max_pending_messages, 'max_pending_messages')
_check_type(int, max_pending_messages_across_partitions, 'max_pending_messages_across_partitions')
_check_type(bool, block_if_queue_full, 'block_if_queue_full')
_check_type(bool, batching_enabled, 'batching_enabled')
_check_type(int, batching_max_messages, 'batching_max_messages')
_check_type(int, batching_max_allowed_size_in_bytes, 'batching_max_allowed_size_in_bytes')
_check_type(int, batching_max_publish_delay_ms, 'batching_max_publish_delay_ms')
_check_type_or_none(dict, properties, 'properties')
conf = _pulsar.ProducerConfiguration()
conf.send_timeout_millis(send_timeout_millis)
conf.compression_type(compression_type)
conf.max_pending_messages(max_pending_messages)
conf.max_pending_messages_across_partitions(max_pending_messages_across_partitions)
conf.block_if_queue_full(block_if_queue_full)
conf.batching_enabled(batching_enabled)
conf.batching_max_messages(batching_max_messages)
conf.batching_max_allowed_size_in_bytes(batching_max_allowed_size_in_bytes)
conf.batching_max_publish_delay_ms(batching_max_publish_delay_ms)
conf.partitions_routing_mode(message_routing_mode)
if producer_name:
conf.producer_name(producer_name)
if initial_sequence_id:
conf.initial_sequence_id(initial_sequence_id)
if properties:
for k, v in properties.items():
conf.property(k, v)
p = Producer()
p._producer = self._client.create_producer(topic, conf)
return p
def subscribe(self, topic, subscription_name,
consumer_type=ConsumerType.Exclusive,
message_listener=None,
receiver_queue_size=1000,
max_total_receiver_queue_size_across_partitions=50000,
consumer_name=None,
unacked_messages_timeout_ms=None,
broker_consumer_stats_cache_time_ms=30000,
is_read_compacted=False,
properties=None,
pattern_auto_discovery_period=60
):
"""
Subscribe to the given topic and subscription combination.
**Args**
* `topic`: The name of the topic, list of topics or regex pattern.
This method will accept these forms:
- `topic='my-topic'`
- `topic=['topic-1', 'topic-2', 'topic-3']`
- `topic=re.compile('topic-.*')`
* `subscription`: The name of the subscription.
**Options**
* `consumer_type`:
Select the subscription type to be used when subscribing to the topic.
* `message_listener`:
Sets a message listener for the consumer. When the listener is set,
the application will receive messages through it. Calls to
`consumer.receive()` will not be allowed. The listener function needs
to accept (consumer, message), for example:
#!python
def my_listener(consumer, message):
# process message
consumer.acknowledge(message)
* `receiver_queue_size`:
Sets the size of the consumer receive queue. The consumer receive
queue controls how many messages can be accumulated by the consumer
before the application calls `receive()`. Using a higher value could
potentially increase the consumer throughput at the expense of higher
memory utilization. Setting the consumer queue size to zero decreases
the throughput of the consumer by disabling pre-fetching of messages.
This approach improves the message distribution on shared subscription
by pushing messages only to those consumers that are ready to process
them. Neither receive with timeout nor partitioned topics can be used
if the consumer queue size is zero. The `receive()` function call
should not be interrupted when the consumer queue size is zero. The
default value is 1000 messages and should work well for most use
cases.
* `max_total_receiver_queue_size_across_partitions`
Set the max total receiver queue size across partitions.
This setting will be used to reduce the receiver queue size for individual partitions
* `consumer_name`:
Sets the consumer name.
* `unacked_messages_timeout_ms`:
Sets the timeout in milliseconds for unacknowledged messages. The
timeout needs to be greater than 10 seconds. An exception is thrown if
the given value is less than 10 seconds. If a successful
acknowledgement is not sent within the timeout, all the unacknowledged
messages are redelivered.
* `broker_consumer_stats_cache_time_ms`:
Sets the time duration for which the broker-side consumer stats will
be cached in the client.
* `properties`:
Sets the properties for the consumer. The properties associated with a consumer
can be used for identify a consumer at broker side.
* `pattern_auto_discovery_period`:
Periods of seconds for consumer to auto discover match topics.
"""
_check_type(str, subscription_name, 'subscription_name')
_check_type(ConsumerType, consumer_type, 'consumer_type')
_check_type(int, receiver_queue_size, 'receiver_queue_size')
_check_type(int, max_total_receiver_queue_size_across_partitions,
'max_total_receiver_queue_size_across_partitions')
_check_type_or_none(str, consumer_name, 'consumer_name')
_check_type_or_none(int, unacked_messages_timeout_ms, 'unacked_messages_timeout_ms')
_check_type(int, broker_consumer_stats_cache_time_ms, 'broker_consumer_stats_cache_time_ms')
_check_type(bool, is_read_compacted, 'is_read_compacted')
_check_type_or_none(dict, properties, 'properties')
conf = _pulsar.ConsumerConfiguration()
conf.consumer_type(consumer_type)
conf.read_compacted(is_read_compacted)
if message_listener:
conf.message_listener(message_listener)
conf.receiver_queue_size(receiver_queue_size)
conf.max_total_receiver_queue_size_across_partitions(max_total_receiver_queue_size_across_partitions)
if consumer_name:
conf.consumer_name(consumer_name)
if unacked_messages_timeout_ms:
conf.unacked_messages_timeout_ms(unacked_messages_timeout_ms)
conf.broker_consumer_stats_cache_time_ms(broker_consumer_stats_cache_time_ms)
if properties:
for k, v in properties.items():
conf.property(k, v)
c = Consumer()
if isinstance(topic, str):
# Single topic
c._consumer = self._client.subscribe(topic, subscription_name, conf)
elif isinstance(topic, list):
# List of topics
c._consumer = self._client.subscribe_topics(topic, subscription_name, conf)
elif isinstance(topic, _retype):
# Regex pattern
c._consumer = self._client.subscribe_pattern(topic.pattern, subscription_name, conf)
else:
raise ValueError("Argument 'topic' is expected to be of a type between (str, list, re.pattern)")
c._client = self
self._consumers.append(c)
return c
def create_reader(self, topic, start_message_id,
reader_listener=None,
receiver_queue_size=1000,
reader_name=None,
subscription_role_prefix=None
):
"""
Create a reader on a particular topic
**Args**
* `topic`: The name of the topic.
* `start_message_id`: The initial reader positioning is done by specifying a message id.
The options are:
* `MessageId.earliest`: Start reading from the earliest message available in the topic
* `MessageId.latest`: Start reading from the end topic, only getting messages published
after the reader was created
* `MessageId`: When passing a particular message id, the reader will position itself on
that specific position. The first message to be read will be the message next to the
specified messageId. Message id can be serialized into a string and deserialized
back into a `MessageId` object:
# Serialize to string
s = msg.message_id().serialize()
# Deserialize from string
msg_id = MessageId.deserialize(s)
**Options**
* `reader_listener`:
Sets a message listener for the reader. When the listener is set,
the application will receive messages through it. Calls to
`reader.read_next()` will not be allowed. The listener function needs
to accept (reader, message), for example:
def my_listener(reader, message):
# process message
pass
* `receiver_queue_size`:
Sets the size of the reader receive queue. The reader receive
queue controls how many messages can be accumulated by the reader
before the application calls `read_next()`. Using a higher value could
potentially increase the reader throughput at the expense of higher
memory utilization.
* `reader_name`:
Sets the reader name.
* `subscription_role_prefix`:
Sets the subscription role prefix.
"""
_check_type(str, topic, 'topic')
_check_type(_pulsar.MessageId, start_message_id, 'start_message_id')
_check_type(int, receiver_queue_size, 'receiver_queue_size')
_check_type_or_none(str, reader_name, 'reader_name')
_check_type_or_none(str, subscription_role_prefix, 'subscription_role_prefix')
conf = _pulsar.ReaderConfiguration()
if reader_listener:
conf.reader_listener(reader_listener)
conf.receiver_queue_size(receiver_queue_size)
if reader_name:
conf.reader_name(reader_name)
if subscription_role_prefix:
conf.subscription_role_prefix(subscription_role_prefix)
c = Reader()
c._reader = self._client.create_reader(topic, start_message_id, conf)
c._client = self
self._consumers.append(c)
return c
def close(self):
"""
Close the client and all the associated producers and consumers
"""
self._client.close()
class Producer:
"""
The Pulsar message producer, used to publish messages on a topic.
"""
def topic(self):
"""
Return the topic which producer is publishing to
"""
return self._producer.topic()
def producer_name(self):
"""
Return the producer name which could have been assigned by the
system or specified by the client
"""
return self._producer.producer_name()
def last_sequence_id(self):
"""
Get the last sequence id that was published by this producer.
This represent either the automatically assigned or custom sequence id
(set on the `MessageBuilder`) that was published and acknowledged by the broker.
After recreating a producer with the same producer name, this will return the
last message that was published in the previous producer session, or -1 if
there no message was ever published.
"""
return self._producer.last_sequence_id()
def send(self, content,
properties=None,
partition_key=None,
sequence_id=None,
replication_clusters=None,
disable_replication=False
):
"""
Publish a message on the topic. Blocks until the message is acknowledged
**Args**
* `content`:
A `bytes` object with the message payload.
**Options**
* `properties`:
A dict of application-defined string properties.
* `partition_key`:
Sets the partition key for message routing. A hash of this key is used
to determine the message's topic partition.
* `sequence_id`:
Specify a custom sequence id for the message being published.
* `replication_clusters`:
Override namespace replication clusters. Note that it is the caller's
responsibility to provide valid cluster names and that all clusters
have been previously configured as topics. Given an empty list,
the message will replicate according to the namespace configuration.
* `disable_replication`:
Do not replicate this message.
"""
msg = self._build_msg(content, properties, partition_key, sequence_id,
replication_clusters, disable_replication)
return self._producer.send(msg)
def send_async(self, content, callback,
properties=None,
partition_key=None,
sequence_id=None,
replication_clusters=None,
disable_replication=False
):
"""
Send a message asynchronously.
The `callback` will be invoked once the message has been acknowledged
by the broker.
Example:
#!python
def callback(res, msg):
print('Message published: %s' % res)
producer.send_async(msg, callback)
When the producer queue is full, by default the message will be rejected
and the callback invoked with an error code.
**Args**
* `content`:
A `bytes` object with the message payload.
**Options**
* `properties`:
A dict of application0-defined string properties.
* `partition_key`:
Sets the partition key for the message routing. A hash of this key is
used to determine the message's topic partition.
* `sequence_id`:
Specify a custom sequence id for the message being published.
* `replication_clusters`: Override namespace replication clusters. Note
that it is the caller's responsibility to provide valid cluster names
and that all clusters have been previously configured as topics.
Given an empty list, the message will replicate per the namespace
configuration.
* `disable_replication`:
Do not replicate this message.
"""
msg = self._build_msg(content, properties, partition_key, sequence_id,
replication_clusters, disable_replication)
self._producer.send_async(msg, callback)
def close(self):
"""
Close the producer.
"""
self._producer.close()
def _build_msg(self, content, properties, partition_key, sequence_id,
replication_clusters, disable_replication):
_check_type(bytes, content, 'content')
_check_type_or_none(dict, properties, 'properties')
_check_type_or_none(str, partition_key, 'partition_key')
_check_type_or_none(int, sequence_id, 'sequence_id')
_check_type_or_none(list, replication_clusters, 'replication_clusters')
_check_type(bool, disable_replication, 'disable_replication')
mb = _pulsar.MessageBuilder()
mb.content(content)
if properties:
for k, v in properties.items():
mb.property(k, v)
if partition_key:
mb.partition_key(partition_key)
if sequence_id:
mb.sequence_id(sequence_id)
if replication_clusters:
mb.replication_clusters(replication_clusters)
if disable_replication:
mb.disable_replication(disable_replication)
return mb.build()
class Consumer:
"""
Pulsar consumer.
"""
def topic(self):
"""
Return the topic this consumer is subscribed to.
"""
return self._consumer.topic()
def subscription_name(self):
"""
Return the subscription name.
"""
return self._consumer.subscription_name()
def unsubscribe(self):
"""
Unsubscribe the current consumer from the topic.
This method will block until the operation is completed. Once the
consumer is unsubscribed, no more messages will be received and
subsequent new messages will not be retained for this consumer.
This consumer object cannot be reused.
"""
return self._consumer.unsubscribe()
def receive(self, timeout_millis=None):
"""
Receive a single message.
If a message is not immediately available, this method will block until
a new message is available.
**Options**
* `timeout_millis`:
If specified, the receive will raise an exception if a message is not
availble within the timeout.
"""
if timeout_millis is None:
return self._consumer.receive()
else:
_check_type(int, timeout_millis, 'timeout_millis')
return self._consumer.receive(timeout_millis)
def acknowledge(self, message):
"""
Acknowledge the reception of a single message.
This method will block until an acknowledgement is sent to the broker.
After that, the message will not be re-delivered to this consumer.
**Args**
* `message`:
The received message or message id.
"""
self._consumer.acknowledge(message)
def acknowledge_cumulative(self, message):
"""
Acknowledge the reception of all the messages in the stream up to (and
including) the provided message.
This method will block until an acknowledgement is sent to the broker.
After that, the messages will not be re-delivered to this consumer.
**Args**
* `message`:
The received message or message id.
"""
self._consumer.acknowledge_cumulative(message)
def pause_message_listener(self):
"""
Pause receiving messages via the `message_listener` until
`resume_message_listener()` is called.
"""
self._consumer.pause_message_listener()
def resume_message_listener(self):
"""
Resume receiving the messages via the message listener.
Asynchronously receive all the messages enqueued from the time
`pause_message_listener()` was called.
"""
self._consumer.resume_message_listener()
def redeliver_unacknowledged_messages(self):
"""
Redelivers all the unacknowledged messages. In failover mode, the
request is ignored if the consumer is not active for the given topic. In
shared mode, the consumer's messages to be redelivered are distributed
across all the connected consumers. This is a non-blocking call and
doesn't throw an exception. In case the connection breaks, the messages
are redelivered after reconnect.
"""
self._consumer.redeliver_unacknowledged_messages()
def seek(self, messageid):
"""
Reset the subscription associated with this consumer to a specific message id.
The message id can either be a specific message or represent the first or last messages in the topic.
Note: this operation can only be done on non-partitioned topics. For these, one can rather perform the
seek() on the individual partitions.
**Args**
* `message`:
The message id for seek.
"""
self._consumer.seek(messageid)
def close(self):
"""
Close the consumer.
"""
self._consumer.close()
self._client._consumers.remove(self)
class Reader:
"""
Pulsar topic reader.
"""
def topic(self):
"""
Return the topic this reader is reading from.
"""
return self._reader.topic()
def read_next(self, timeout_millis=None):
"""
Read a single message.
If a message is not immediately available, this method will block until
a new message is available.
**Options**
* `timeout_millis`:
If specified, the receive will raise an exception if a message is not
available within the timeout.
"""
if timeout_millis is None:
return self._reader.read_next()
else:
_check_type(int, timeout_millis, 'timeout_millis')
return self._reader.read_next(timeout_millis)
def has_message_available(self):
"""
Check if there is any message available to read from the current position.
"""
return self._reader.has_message_available();
def close(self):
"""
Close the reader.
"""
self._reader.close()
self._client._consumers.remove(self)
def _check_type(var_type, var, name):
if not isinstance(var, var_type):
raise ValueError("Argument %s is expected to be of type '%s'" % (name, var_type.__name__))
def _check_type_or_none(var_type, var, name):
if var is not None and not isinstance(var, var_type):
raise ValueError("Argument %s is expected to be either None or of type '%s'"
% (name, var_type.__name__))
Sub-modules
pulsar.functions
Classes
class Authentication (dynamicLibPath, authParamsString)
-
Authentication provider object. Used to load authentication from an external shared library.
Create the authentication provider instance.
Args
dynamicLibPath
: Path to the authentication provider shared library (such astls.so
)authParamsString
: Comma-separated list of provider-specific configuration params
Expand source code
class Authentication: """ Authentication provider object. Used to load authentication from an external shared library. """ def __init__(self, dynamicLibPath, authParamsString): """ Create the authentication provider instance. **Args** * `dynamicLibPath`: Path to the authentication provider shared library (such as `tls.so`) * `authParamsString`: Comma-separated list of provider-specific configuration params """ _check_type(str, dynamicLibPath, 'dynamicLibPath') _check_type(str, authParamsString, 'authParamsString') self.auth = _pulsar.Authentication(dynamicLibPath, authParamsString)
Subclasses
class AuthenticationAthenz (auth_params_string)
-
Athenz Authentication implementation
Create the Athenz authentication provider instance.
Args
auth_params_string
: JSON encoded configuration for Athenz client
Expand source code
class AuthenticationAthenz(Authentication): """ Athenz Authentication implementation """ def __init__(self, auth_params_string): """ Create the Athenz authentication provider instance. **Args** * `auth_params_string`: JSON encoded configuration for Athenz client """ _check_type(str, auth_params_string, 'auth_params_string') self.auth = _pulsar.AuthenticationAthenz(auth_params_string)
Ancestors
class AuthenticationTLS (certificate_path, private_key_path)
-
TLS Authentication implementation
Create the TLS authentication provider instance.
Args
certificatePath
: Path to the public certificateprivateKeyPath
: Path to private TLS key
Expand source code
class AuthenticationTLS(Authentication): """ TLS Authentication implementation """ def __init__(self, certificate_path, private_key_path): """ Create the TLS authentication provider instance. **Args** * `certificatePath`: Path to the public certificate * `privateKeyPath`: Path to private TLS key """ _check_type(str, certificate_path, 'certificate_path') _check_type(str, private_key_path, 'private_key_path') self.auth = _pulsar.AuthenticationTLS(certificate_path, private_key_path)
Ancestors
class Client (service_url, authentication=None, operation_timeout_seconds=30, io_threads=1, message_listener_threads=1, concurrent_lookup_requests=50000, log_conf_file_path=None, use_tls=False, tls_trust_certs_file_path=None, tls_allow_insecure_connection=False)
-
The Pulsar client. A single client instance can be used to create producers and consumers on multiple topics.
The client will share the same connection pool and threads across all producers and consumers.
Create a new Pulsar client instance.
Args
service_url
: The Pulsar service url eg: pulsar://my-broker.com:6650/
Options
authentication
: Set the authentication provider to be used with the broker. For example:AuthenticationTls
orAuthenticationAthenz
operation_timeout_seconds
: Set timeout on client operations (subscribe, create producer, close, unsubscribe).io_threads
: Set the number of IO threads to be used by the Pulsar client.message_listener_threads
: Set the number of threads to be used by the Pulsar client when delivering messages through message listener. The default is 1 thread per Pulsar client. If using more than 1 thread, messages for distinctmessage_listener
s will be delivered in different threads, however a singleMessageListener
will always be assigned to the same thread.concurrent_lookup_requests
: Number of concurrent lookup-requests allowed on each broker connection to prevent overload on the broker.log_conf_file_path
: Initialize log4cxx from a configuration file.use_tls
: Configure whether to use TLS encryption on the connection. This setting is deprecated. TLS will be automatically enabled if theserviceUrl
is set topulsar+ssl://
or<https://
>tls_trust_certs_file_path
: Set the path to the trusted TLS certificate file.tls_allow_insecure_connection
: Configure whether the Pulsar client accepts untrusted TLS certificates from the broker.
Expand source code
class Client: """ The Pulsar client. A single client instance can be used to create producers and consumers on multiple topics. The client will share the same connection pool and threads across all producers and consumers. """ def __init__(self, service_url, authentication=None, operation_timeout_seconds=30, io_threads=1, message_listener_threads=1, concurrent_lookup_requests=50000, log_conf_file_path=None, use_tls=False, tls_trust_certs_file_path=None, tls_allow_insecure_connection=False ): """ Create a new Pulsar client instance. **Args** * `service_url`: The Pulsar service url eg: pulsar://my-broker.com:6650/ **Options** * `authentication`: Set the authentication provider to be used with the broker. For example: `AuthenticationTls` or `AuthenticationAthenz` * `operation_timeout_seconds`: Set timeout on client operations (subscribe, create producer, close, unsubscribe). * `io_threads`: Set the number of IO threads to be used by the Pulsar client. * `message_listener_threads`: Set the number of threads to be used by the Pulsar client when delivering messages through message listener. The default is 1 thread per Pulsar client. If using more than 1 thread, messages for distinct `message_listener`s will be delivered in different threads, however a single `MessageListener` will always be assigned to the same thread. * `concurrent_lookup_requests`: Number of concurrent lookup-requests allowed on each broker connection to prevent overload on the broker. * `log_conf_file_path`: Initialize log4cxx from a configuration file. * `use_tls`: Configure whether to use TLS encryption on the connection. This setting is deprecated. TLS will be automatically enabled if the `serviceUrl` is set to `pulsar+ssl://` or `https://` * `tls_trust_certs_file_path`: Set the path to the trusted TLS certificate file. * `tls_allow_insecure_connection`: Configure whether the Pulsar client accepts untrusted TLS certificates from the broker. """ _check_type(str, service_url, 'service_url') _check_type_or_none(Authentication, authentication, 'authentication') _check_type(int, operation_timeout_seconds, 'operation_timeout_seconds') _check_type(int, io_threads, 'io_threads') _check_type(int, message_listener_threads, 'message_listener_threads') _check_type(int, concurrent_lookup_requests, 'concurrent_lookup_requests') _check_type_or_none(str, log_conf_file_path, 'log_conf_file_path') _check_type(bool, use_tls, 'use_tls') _check_type_or_none(str, tls_trust_certs_file_path, 'tls_trust_certs_file_path') _check_type(bool, tls_allow_insecure_connection, 'tls_allow_insecure_connection') conf = _pulsar.ClientConfiguration() if authentication: conf.authentication(authentication.auth) conf.operation_timeout_seconds(operation_timeout_seconds) conf.io_threads(io_threads) conf.message_listener_threads(message_listener_threads) conf.concurrent_lookup_requests(concurrent_lookup_requests) if log_conf_file_path: conf.log_conf_file_path(log_conf_file_path) if use_tls or service_url.startswith('pulsar+ssl://') or service_url.startswith('https://'): conf.use_tls(True) if tls_trust_certs_file_path: conf.tls_trust_certs_file_path(tls_trust_certs_file_path) conf.tls_allow_insecure_connection(tls_allow_insecure_connection) self._client = _pulsar.Client(service_url, conf) self._consumers = [] def create_producer(self, topic, producer_name=None, initial_sequence_id=None, send_timeout_millis=30000, compression_type=CompressionType.NONE, max_pending_messages=1000, max_pending_messages_across_partitions=50000, block_if_queue_full=False, batching_enabled=False, batching_max_messages=1000, batching_max_allowed_size_in_bytes=128*1024, batching_max_publish_delay_ms=10, message_routing_mode=PartitionsRoutingMode.RoundRobinDistribution, properties=None, ): """ Create a new producer on a given topic. **Args** * `topic`: The topic name **Options** * `producer_name`: Specify a name for the producer. If not assigned, the system will generate a globally unique name which can be accessed with `Producer.producer_name()`. When specifying a name, it is app to the user to ensure that, for a given topic, the producer name is unique across all Pulsar's clusters. * `initial_sequence_id`: Set the baseline for the sequence ids for messages published by the producer. First message will be using `(initialSequenceId + 1)`` as its sequence id and subsequent messages will be assigned incremental sequence ids, if not otherwise specified. * `send_timeout_seconds`: If a message is not acknowledged by the server before the `send_timeout` expires, an error will be reported. * `compression_type`: Set the compression type for the producer. By default, message payloads are not compressed. Supported compression types are `CompressionType.LZ4` and `CompressionType.ZLib`. * `max_pending_messages`: Set the max size of the queue holding the messages pending to receive an acknowledgment from the broker. * `max_pending_messages_across_partitions`: Set the max size of the queue holding the messages pending to receive an acknowledgment across partitions from the broker. * `block_if_queue_full`: Set whether `send_async` operations should block when the outgoing message queue is full. * `message_routing_mode`: Set the message routing mode for the partitioned producer. Default is `PartitionsRoutingMode.RoundRobinDistribution`, other option is `PartitionsRoutingMode.UseSinglePartition` * `properties`: Sets the properties for the producer. The properties associated with a producer can be used for identify a producer at broker side. """ _check_type(str, topic, 'topic') _check_type_or_none(str, producer_name, 'producer_name') _check_type_or_none(int, initial_sequence_id, 'initial_sequence_id') _check_type(int, send_timeout_millis, 'send_timeout_millis') _check_type(CompressionType, compression_type, 'compression_type') _check_type(int, max_pending_messages, 'max_pending_messages') _check_type(int, max_pending_messages_across_partitions, 'max_pending_messages_across_partitions') _check_type(bool, block_if_queue_full, 'block_if_queue_full') _check_type(bool, batching_enabled, 'batching_enabled') _check_type(int, batching_max_messages, 'batching_max_messages') _check_type(int, batching_max_allowed_size_in_bytes, 'batching_max_allowed_size_in_bytes') _check_type(int, batching_max_publish_delay_ms, 'batching_max_publish_delay_ms') _check_type_or_none(dict, properties, 'properties') conf = _pulsar.ProducerConfiguration() conf.send_timeout_millis(send_timeout_millis) conf.compression_type(compression_type) conf.max_pending_messages(max_pending_messages) conf.max_pending_messages_across_partitions(max_pending_messages_across_partitions) conf.block_if_queue_full(block_if_queue_full) conf.batching_enabled(batching_enabled) conf.batching_max_messages(batching_max_messages) conf.batching_max_allowed_size_in_bytes(batching_max_allowed_size_in_bytes) conf.batching_max_publish_delay_ms(batching_max_publish_delay_ms) conf.partitions_routing_mode(message_routing_mode) if producer_name: conf.producer_name(producer_name) if initial_sequence_id: conf.initial_sequence_id(initial_sequence_id) if properties: for k, v in properties.items(): conf.property(k, v) p = Producer() p._producer = self._client.create_producer(topic, conf) return p def subscribe(self, topic, subscription_name, consumer_type=ConsumerType.Exclusive, message_listener=None, receiver_queue_size=1000, max_total_receiver_queue_size_across_partitions=50000, consumer_name=None, unacked_messages_timeout_ms=None, broker_consumer_stats_cache_time_ms=30000, is_read_compacted=False, properties=None, pattern_auto_discovery_period=60 ): """ Subscribe to the given topic and subscription combination. **Args** * `topic`: The name of the topic, list of topics or regex pattern. This method will accept these forms: - `topic='my-topic'` - `topic=['topic-1', 'topic-2', 'topic-3']` - `topic=re.compile('topic-.*')` * `subscription`: The name of the subscription. **Options** * `consumer_type`: Select the subscription type to be used when subscribing to the topic. * `message_listener`: Sets a message listener for the consumer. When the listener is set, the application will receive messages through it. Calls to `consumer.receive()` will not be allowed. The listener function needs to accept (consumer, message), for example: #!python def my_listener(consumer, message): # process message consumer.acknowledge(message) * `receiver_queue_size`: Sets the size of the consumer receive queue. The consumer receive queue controls how many messages can be accumulated by the consumer before the application calls `receive()`. Using a higher value could potentially increase the consumer throughput at the expense of higher memory utilization. Setting the consumer queue size to zero decreases the throughput of the consumer by disabling pre-fetching of messages. This approach improves the message distribution on shared subscription by pushing messages only to those consumers that are ready to process them. Neither receive with timeout nor partitioned topics can be used if the consumer queue size is zero. The `receive()` function call should not be interrupted when the consumer queue size is zero. The default value is 1000 messages and should work well for most use cases. * `max_total_receiver_queue_size_across_partitions` Set the max total receiver queue size across partitions. This setting will be used to reduce the receiver queue size for individual partitions * `consumer_name`: Sets the consumer name. * `unacked_messages_timeout_ms`: Sets the timeout in milliseconds for unacknowledged messages. The timeout needs to be greater than 10 seconds. An exception is thrown if the given value is less than 10 seconds. If a successful acknowledgement is not sent within the timeout, all the unacknowledged messages are redelivered. * `broker_consumer_stats_cache_time_ms`: Sets the time duration for which the broker-side consumer stats will be cached in the client. * `properties`: Sets the properties for the consumer. The properties associated with a consumer can be used for identify a consumer at broker side. * `pattern_auto_discovery_period`: Periods of seconds for consumer to auto discover match topics. """ _check_type(str, subscription_name, 'subscription_name') _check_type(ConsumerType, consumer_type, 'consumer_type') _check_type(int, receiver_queue_size, 'receiver_queue_size') _check_type(int, max_total_receiver_queue_size_across_partitions, 'max_total_receiver_queue_size_across_partitions') _check_type_or_none(str, consumer_name, 'consumer_name') _check_type_or_none(int, unacked_messages_timeout_ms, 'unacked_messages_timeout_ms') _check_type(int, broker_consumer_stats_cache_time_ms, 'broker_consumer_stats_cache_time_ms') _check_type(bool, is_read_compacted, 'is_read_compacted') _check_type_or_none(dict, properties, 'properties') conf = _pulsar.ConsumerConfiguration() conf.consumer_type(consumer_type) conf.read_compacted(is_read_compacted) if message_listener: conf.message_listener(message_listener) conf.receiver_queue_size(receiver_queue_size) conf.max_total_receiver_queue_size_across_partitions(max_total_receiver_queue_size_across_partitions) if consumer_name: conf.consumer_name(consumer_name) if unacked_messages_timeout_ms: conf.unacked_messages_timeout_ms(unacked_messages_timeout_ms) conf.broker_consumer_stats_cache_time_ms(broker_consumer_stats_cache_time_ms) if properties: for k, v in properties.items(): conf.property(k, v) c = Consumer() if isinstance(topic, str): # Single topic c._consumer = self._client.subscribe(topic, subscription_name, conf) elif isinstance(topic, list): # List of topics c._consumer = self._client.subscribe_topics(topic, subscription_name, conf) elif isinstance(topic, _retype): # Regex pattern c._consumer = self._client.subscribe_pattern(topic.pattern, subscription_name, conf) else: raise ValueError("Argument 'topic' is expected to be of a type between (str, list, re.pattern)") c._client = self self._consumers.append(c) return c def create_reader(self, topic, start_message_id, reader_listener=None, receiver_queue_size=1000, reader_name=None, subscription_role_prefix=None ): """ Create a reader on a particular topic **Args** * `topic`: The name of the topic. * `start_message_id`: The initial reader positioning is done by specifying a message id. The options are: * `MessageId.earliest`: Start reading from the earliest message available in the topic * `MessageId.latest`: Start reading from the end topic, only getting messages published after the reader was created * `MessageId`: When passing a particular message id, the reader will position itself on that specific position. The first message to be read will be the message next to the specified messageId. Message id can be serialized into a string and deserialized back into a `MessageId` object: # Serialize to string s = msg.message_id().serialize() # Deserialize from string msg_id = MessageId.deserialize(s) **Options** * `reader_listener`: Sets a message listener for the reader. When the listener is set, the application will receive messages through it. Calls to `reader.read_next()` will not be allowed. The listener function needs to accept (reader, message), for example: def my_listener(reader, message): # process message pass * `receiver_queue_size`: Sets the size of the reader receive queue. The reader receive queue controls how many messages can be accumulated by the reader before the application calls `read_next()`. Using a higher value could potentially increase the reader throughput at the expense of higher memory utilization. * `reader_name`: Sets the reader name. * `subscription_role_prefix`: Sets the subscription role prefix. """ _check_type(str, topic, 'topic') _check_type(_pulsar.MessageId, start_message_id, 'start_message_id') _check_type(int, receiver_queue_size, 'receiver_queue_size') _check_type_or_none(str, reader_name, 'reader_name') _check_type_or_none(str, subscription_role_prefix, 'subscription_role_prefix') conf = _pulsar.ReaderConfiguration() if reader_listener: conf.reader_listener(reader_listener) conf.receiver_queue_size(receiver_queue_size) if reader_name: conf.reader_name(reader_name) if subscription_role_prefix: conf.subscription_role_prefix(subscription_role_prefix) c = Reader() c._reader = self._client.create_reader(topic, start_message_id, conf) c._client = self self._consumers.append(c) return c def close(self): """ Close the client and all the associated producers and consumers """ self._client.close()
Methods
def close(self)
-
Close the client and all the associated producers and consumers
Expand source code
def close(self): """ Close the client and all the associated producers and consumers """ self._client.close()
def create_producer(self, topic, producer_name=None, initial_sequence_id=None, send_timeout_millis=30000, compression_type=_pulsar.CompressionType.NONE, max_pending_messages=1000, max_pending_messages_across_partitions=50000, block_if_queue_full=False, batching_enabled=False, batching_max_messages=1000, batching_max_allowed_size_in_bytes=131072, batching_max_publish_delay_ms=10, message_routing_mode=_pulsar.PartitionsRoutingMode.RoundRobinDistribution, properties=None)
-
Create a new producer on a given topic.
Args
topic
: The topic name
Options
producer_name
: Specify a name for the producer. If not assigned, the system will generate a globally unique name which can be accessed withProducer.producer_name()
. When specifying a name, it is app to the user to ensure that, for a given topic, the producer name is unique across all Pulsar's clusters.initial_sequence_id
: Set the baseline for the sequence ids for messages published by the producer. First message will be using `(initialSequenceId + 1)`` as its sequence id and subsequent messages will be assigned incremental sequence ids, if not otherwise specified.send_timeout_seconds
: If a message is not acknowledged by the server before thesend_timeout
expires, an error will be reported.compression_type
: Set the compression type for the producer. By default, message payloads are not compressed. Supported compression types areCompressionType.LZ4
andCompressionType.ZLib
.max_pending_messages
: Set the max size of the queue holding the messages pending to receive an acknowledgment from the broker.max_pending_messages_across_partitions
: Set the max size of the queue holding the messages pending to receive an acknowledgment across partitions from the broker.block_if_queue_full
: Set whethersend_async
operations should block when the outgoing message queue is full.message_routing_mode
: Set the message routing mode for the partitioned producer. Default isPartitionsRoutingMode.RoundRobinDistribution
, other option isPartitionsRoutingMode.UseSinglePartition
properties
: Sets the properties for the producer. The properties associated with a producer can be used for identify a producer at broker side.
Expand source code
def create_producer(self, topic, producer_name=None, initial_sequence_id=None, send_timeout_millis=30000, compression_type=CompressionType.NONE, max_pending_messages=1000, max_pending_messages_across_partitions=50000, block_if_queue_full=False, batching_enabled=False, batching_max_messages=1000, batching_max_allowed_size_in_bytes=128*1024, batching_max_publish_delay_ms=10, message_routing_mode=PartitionsRoutingMode.RoundRobinDistribution, properties=None, ): """ Create a new producer on a given topic. **Args** * `topic`: The topic name **Options** * `producer_name`: Specify a name for the producer. If not assigned, the system will generate a globally unique name which can be accessed with `Producer.producer_name()`. When specifying a name, it is app to the user to ensure that, for a given topic, the producer name is unique across all Pulsar's clusters. * `initial_sequence_id`: Set the baseline for the sequence ids for messages published by the producer. First message will be using `(initialSequenceId + 1)`` as its sequence id and subsequent messages will be assigned incremental sequence ids, if not otherwise specified. * `send_timeout_seconds`: If a message is not acknowledged by the server before the `send_timeout` expires, an error will be reported. * `compression_type`: Set the compression type for the producer. By default, message payloads are not compressed. Supported compression types are `CompressionType.LZ4` and `CompressionType.ZLib`. * `max_pending_messages`: Set the max size of the queue holding the messages pending to receive an acknowledgment from the broker. * `max_pending_messages_across_partitions`: Set the max size of the queue holding the messages pending to receive an acknowledgment across partitions from the broker. * `block_if_queue_full`: Set whether `send_async` operations should block when the outgoing message queue is full. * `message_routing_mode`: Set the message routing mode for the partitioned producer. Default is `PartitionsRoutingMode.RoundRobinDistribution`, other option is `PartitionsRoutingMode.UseSinglePartition` * `properties`: Sets the properties for the producer. The properties associated with a producer can be used for identify a producer at broker side. """ _check_type(str, topic, 'topic') _check_type_or_none(str, producer_name, 'producer_name') _check_type_or_none(int, initial_sequence_id, 'initial_sequence_id') _check_type(int, send_timeout_millis, 'send_timeout_millis') _check_type(CompressionType, compression_type, 'compression_type') _check_type(int, max_pending_messages, 'max_pending_messages') _check_type(int, max_pending_messages_across_partitions, 'max_pending_messages_across_partitions') _check_type(bool, block_if_queue_full, 'block_if_queue_full') _check_type(bool, batching_enabled, 'batching_enabled') _check_type(int, batching_max_messages, 'batching_max_messages') _check_type(int, batching_max_allowed_size_in_bytes, 'batching_max_allowed_size_in_bytes') _check_type(int, batching_max_publish_delay_ms, 'batching_max_publish_delay_ms') _check_type_or_none(dict, properties, 'properties') conf = _pulsar.ProducerConfiguration() conf.send_timeout_millis(send_timeout_millis) conf.compression_type(compression_type) conf.max_pending_messages(max_pending_messages) conf.max_pending_messages_across_partitions(max_pending_messages_across_partitions) conf.block_if_queue_full(block_if_queue_full) conf.batching_enabled(batching_enabled) conf.batching_max_messages(batching_max_messages) conf.batching_max_allowed_size_in_bytes(batching_max_allowed_size_in_bytes) conf.batching_max_publish_delay_ms(batching_max_publish_delay_ms) conf.partitions_routing_mode(message_routing_mode) if producer_name: conf.producer_name(producer_name) if initial_sequence_id: conf.initial_sequence_id(initial_sequence_id) if properties: for k, v in properties.items(): conf.property(k, v) p = Producer() p._producer = self._client.create_producer(topic, conf) return p
def create_reader(self, topic, start_message_id, reader_listener=None, receiver_queue_size=1000, reader_name=None, subscription_role_prefix=None)
-
Create a reader on a particular topic
Args
topic
: The name of the topic.start_message_id
: The initial reader positioning is done by specifying a message id. The options are:MessageId.earliest
: Start reading from the earliest message available in the topicMessageId.latest
: Start reading from the end topic, only getting messages published after the reader was created-
MessageId
: When passing a particular message id, the reader will position itself on that specific position. The first message to be read will be the message next to the specified messageId. Message id can be serialized into a string and deserialized back into aMessageId
object:# Serialize to string s = msg.message_id().serialize()
# Deserialize from string msg_id = MessageId.deserialize(s)
Options
-
reader_listener
: Sets a message listener for the reader. When the listener is set, the application will receive messages through it. Calls toreader.read_next()
will not be allowed. The listener function needs to accept (reader, message), for example:def my_listener(reader, message): # process message pass
-
receiver_queue_size
: Sets the size of the reader receive queue. The reader receive queue controls how many messages can be accumulated by the reader before the application callsread_next()
. Using a higher value could potentially increase the reader throughput at the expense of higher memory utilization. reader_name
: Sets the reader name.subscription_role_prefix
: Sets the subscription role prefix.
Expand source code
def create_reader(self, topic, start_message_id, reader_listener=None, receiver_queue_size=1000, reader_name=None, subscription_role_prefix=None ): """ Create a reader on a particular topic **Args** * `topic`: The name of the topic. * `start_message_id`: The initial reader positioning is done by specifying a message id. The options are: * `MessageId.earliest`: Start reading from the earliest message available in the topic * `MessageId.latest`: Start reading from the end topic, only getting messages published after the reader was created * `MessageId`: When passing a particular message id, the reader will position itself on that specific position. The first message to be read will be the message next to the specified messageId. Message id can be serialized into a string and deserialized back into a `MessageId` object: # Serialize to string s = msg.message_id().serialize() # Deserialize from string msg_id = MessageId.deserialize(s) **Options** * `reader_listener`: Sets a message listener for the reader. When the listener is set, the application will receive messages through it. Calls to `reader.read_next()` will not be allowed. The listener function needs to accept (reader, message), for example: def my_listener(reader, message): # process message pass * `receiver_queue_size`: Sets the size of the reader receive queue. The reader receive queue controls how many messages can be accumulated by the reader before the application calls `read_next()`. Using a higher value could potentially increase the reader throughput at the expense of higher memory utilization. * `reader_name`: Sets the reader name. * `subscription_role_prefix`: Sets the subscription role prefix. """ _check_type(str, topic, 'topic') _check_type(_pulsar.MessageId, start_message_id, 'start_message_id') _check_type(int, receiver_queue_size, 'receiver_queue_size') _check_type_or_none(str, reader_name, 'reader_name') _check_type_or_none(str, subscription_role_prefix, 'subscription_role_prefix') conf = _pulsar.ReaderConfiguration() if reader_listener: conf.reader_listener(reader_listener) conf.receiver_queue_size(receiver_queue_size) if reader_name: conf.reader_name(reader_name) if subscription_role_prefix: conf.subscription_role_prefix(subscription_role_prefix) c = Reader() c._reader = self._client.create_reader(topic, start_message_id, conf) c._client = self self._consumers.append(c) return c
def subscribe(self, topic, subscription_name, consumer_type=_pulsar.ConsumerType.Exclusive, message_listener=None, receiver_queue_size=1000, max_total_receiver_queue_size_across_partitions=50000, consumer_name=None, unacked_messages_timeout_ms=None, broker_consumer_stats_cache_time_ms=30000, is_read_compacted=False, properties=None, pattern_auto_discovery_period=60)
-
Subscribe to the given topic and subscription combination.
Args
topic
: The name of the topic, list of topics or regex pattern. This method will accept these forms: -topic='my-topic'
-topic=['topic-1', 'topic-2', 'topic-3']
-topic=re.compile('topic-.*')
subscription
: The name of the subscription.
Options
consumer_type
: Select the subscription type to be used when subscribing to the topic.-
message_listener
: Sets a message listener for the consumer. When the listener is set, the application will receive messages through it. Calls toconsumer.receive()
will not be allowed. The listener function needs to accept (consumer, message), for example:#!python def my_listener(consumer, message): # process message consumer.acknowledge(message)
-
receiver_queue_size
: Sets the size of the consumer receive queue. The consumer receive queue controls how many messages can be accumulated by the consumer before the application callsreceive()
. Using a higher value could potentially increase the consumer throughput at the expense of higher memory utilization. Setting the consumer queue size to zero decreases the throughput of the consumer by disabling pre-fetching of messages. This approach improves the message distribution on shared subscription by pushing messages only to those consumers that are ready to process them. Neither receive with timeout nor partitioned topics can be used if the consumer queue size is zero. Thereceive()
function call should not be interrupted when the consumer queue size is zero. The default value is 1000 messages and should work well for most use cases. max_total_receiver_queue_size_across_partitions
Set the max total receiver queue size across partitions. This setting will be used to reduce the receiver queue size for individual partitionsconsumer_name
: Sets the consumer name.unacked_messages_timeout_ms
: Sets the timeout in milliseconds for unacknowledged messages. The timeout needs to be greater than 10 seconds. An exception is thrown if the given value is less than 10 seconds. If a successful acknowledgement is not sent within the timeout, all the unacknowledged messages are redelivered.broker_consumer_stats_cache_time_ms
: Sets the time duration for which the broker-side consumer stats will be cached in the client.properties
: Sets the properties for the consumer. The properties associated with a consumer can be used for identify a consumer at broker side.pattern_auto_discovery_period
: Periods of seconds for consumer to auto discover match topics.
Expand source code
def subscribe(self, topic, subscription_name, consumer_type=ConsumerType.Exclusive, message_listener=None, receiver_queue_size=1000, max_total_receiver_queue_size_across_partitions=50000, consumer_name=None, unacked_messages_timeout_ms=None, broker_consumer_stats_cache_time_ms=30000, is_read_compacted=False, properties=None, pattern_auto_discovery_period=60 ): """ Subscribe to the given topic and subscription combination. **Args** * `topic`: The name of the topic, list of topics or regex pattern. This method will accept these forms: - `topic='my-topic'` - `topic=['topic-1', 'topic-2', 'topic-3']` - `topic=re.compile('topic-.*')` * `subscription`: The name of the subscription. **Options** * `consumer_type`: Select the subscription type to be used when subscribing to the topic. * `message_listener`: Sets a message listener for the consumer. When the listener is set, the application will receive messages through it. Calls to `consumer.receive()` will not be allowed. The listener function needs to accept (consumer, message), for example: #!python def my_listener(consumer, message): # process message consumer.acknowledge(message) * `receiver_queue_size`: Sets the size of the consumer receive queue. The consumer receive queue controls how many messages can be accumulated by the consumer before the application calls `receive()`. Using a higher value could potentially increase the consumer throughput at the expense of higher memory utilization. Setting the consumer queue size to zero decreases the throughput of the consumer by disabling pre-fetching of messages. This approach improves the message distribution on shared subscription by pushing messages only to those consumers that are ready to process them. Neither receive with timeout nor partitioned topics can be used if the consumer queue size is zero. The `receive()` function call should not be interrupted when the consumer queue size is zero. The default value is 1000 messages and should work well for most use cases. * `max_total_receiver_queue_size_across_partitions` Set the max total receiver queue size across partitions. This setting will be used to reduce the receiver queue size for individual partitions * `consumer_name`: Sets the consumer name. * `unacked_messages_timeout_ms`: Sets the timeout in milliseconds for unacknowledged messages. The timeout needs to be greater than 10 seconds. An exception is thrown if the given value is less than 10 seconds. If a successful acknowledgement is not sent within the timeout, all the unacknowledged messages are redelivered. * `broker_consumer_stats_cache_time_ms`: Sets the time duration for which the broker-side consumer stats will be cached in the client. * `properties`: Sets the properties for the consumer. The properties associated with a consumer can be used for identify a consumer at broker side. * `pattern_auto_discovery_period`: Periods of seconds for consumer to auto discover match topics. """ _check_type(str, subscription_name, 'subscription_name') _check_type(ConsumerType, consumer_type, 'consumer_type') _check_type(int, receiver_queue_size, 'receiver_queue_size') _check_type(int, max_total_receiver_queue_size_across_partitions, 'max_total_receiver_queue_size_across_partitions') _check_type_or_none(str, consumer_name, 'consumer_name') _check_type_or_none(int, unacked_messages_timeout_ms, 'unacked_messages_timeout_ms') _check_type(int, broker_consumer_stats_cache_time_ms, 'broker_consumer_stats_cache_time_ms') _check_type(bool, is_read_compacted, 'is_read_compacted') _check_type_or_none(dict, properties, 'properties') conf = _pulsar.ConsumerConfiguration() conf.consumer_type(consumer_type) conf.read_compacted(is_read_compacted) if message_listener: conf.message_listener(message_listener) conf.receiver_queue_size(receiver_queue_size) conf.max_total_receiver_queue_size_across_partitions(max_total_receiver_queue_size_across_partitions) if consumer_name: conf.consumer_name(consumer_name) if unacked_messages_timeout_ms: conf.unacked_messages_timeout_ms(unacked_messages_timeout_ms) conf.broker_consumer_stats_cache_time_ms(broker_consumer_stats_cache_time_ms) if properties: for k, v in properties.items(): conf.property(k, v) c = Consumer() if isinstance(topic, str): # Single topic c._consumer = self._client.subscribe(topic, subscription_name, conf) elif isinstance(topic, list): # List of topics c._consumer = self._client.subscribe_topics(topic, subscription_name, conf) elif isinstance(topic, _retype): # Regex pattern c._consumer = self._client.subscribe_pattern(topic.pattern, subscription_name, conf) else: raise ValueError("Argument 'topic' is expected to be of a type between (str, list, re.pattern)") c._client = self self._consumers.append(c) return c
class Consumer (*args, **kwargs)
-
Pulsar consumer.
Expand source code
class Consumer: """ Pulsar consumer. """ def topic(self): """ Return the topic this consumer is subscribed to. """ return self._consumer.topic() def subscription_name(self): """ Return the subscription name. """ return self._consumer.subscription_name() def unsubscribe(self): """ Unsubscribe the current consumer from the topic. This method will block until the operation is completed. Once the consumer is unsubscribed, no more messages will be received and subsequent new messages will not be retained for this consumer. This consumer object cannot be reused. """ return self._consumer.unsubscribe() def receive(self, timeout_millis=None): """ Receive a single message. If a message is not immediately available, this method will block until a new message is available. **Options** * `timeout_millis`: If specified, the receive will raise an exception if a message is not availble within the timeout. """ if timeout_millis is None: return self._consumer.receive() else: _check_type(int, timeout_millis, 'timeout_millis') return self._consumer.receive(timeout_millis) def acknowledge(self, message): """ Acknowledge the reception of a single message. This method will block until an acknowledgement is sent to the broker. After that, the message will not be re-delivered to this consumer. **Args** * `message`: The received message or message id. """ self._consumer.acknowledge(message) def acknowledge_cumulative(self, message): """ Acknowledge the reception of all the messages in the stream up to (and including) the provided message. This method will block until an acknowledgement is sent to the broker. After that, the messages will not be re-delivered to this consumer. **Args** * `message`: The received message or message id. """ self._consumer.acknowledge_cumulative(message) def pause_message_listener(self): """ Pause receiving messages via the `message_listener` until `resume_message_listener()` is called. """ self._consumer.pause_message_listener() def resume_message_listener(self): """ Resume receiving the messages via the message listener. Asynchronously receive all the messages enqueued from the time `pause_message_listener()` was called. """ self._consumer.resume_message_listener() def redeliver_unacknowledged_messages(self): """ Redelivers all the unacknowledged messages. In failover mode, the request is ignored if the consumer is not active for the given topic. In shared mode, the consumer's messages to be redelivered are distributed across all the connected consumers. This is a non-blocking call and doesn't throw an exception. In case the connection breaks, the messages are redelivered after reconnect. """ self._consumer.redeliver_unacknowledged_messages() def seek(self, messageid): """ Reset the subscription associated with this consumer to a specific message id. The message id can either be a specific message or represent the first or last messages in the topic. Note: this operation can only be done on non-partitioned topics. For these, one can rather perform the seek() on the individual partitions. **Args** * `message`: The message id for seek. """ self._consumer.seek(messageid) def close(self): """ Close the consumer. """ self._consumer.close() self._client._consumers.remove(self)
Methods
def acknowledge(self, message)
-
Acknowledge the reception of a single message.
This method will block until an acknowledgement is sent to the broker. After that, the message will not be re-delivered to this consumer.
Args
message
: The received message or message id.
Expand source code
def acknowledge(self, message): """ Acknowledge the reception of a single message. This method will block until an acknowledgement is sent to the broker. After that, the message will not be re-delivered to this consumer. **Args** * `message`: The received message or message id. """ self._consumer.acknowledge(message)
def acknowledge_cumulative(self, message)
-
Acknowledge the reception of all the messages in the stream up to (and including) the provided message.
This method will block until an acknowledgement is sent to the broker. After that, the messages will not be re-delivered to this consumer.
Args
message
: The received message or message id.
Expand source code
def acknowledge_cumulative(self, message): """ Acknowledge the reception of all the messages in the stream up to (and including) the provided message. This method will block until an acknowledgement is sent to the broker. After that, the messages will not be re-delivered to this consumer. **Args** * `message`: The received message or message id. """ self._consumer.acknowledge_cumulative(message)
def close(self)
-
Close the consumer.
Expand source code
def close(self): """ Close the consumer. """ self._consumer.close() self._client._consumers.remove(self)
def pause_message_listener(self)
-
Pause receiving messages via the
message_listener
untilresume_message_listener()
is called.Expand source code
def pause_message_listener(self): """ Pause receiving messages via the `message_listener` until `resume_message_listener()` is called. """ self._consumer.pause_message_listener()
def receive(self, timeout_millis=None)
-
Receive a single message.
If a message is not immediately available, this method will block until a new message is available.
Options
timeout_millis
: If specified, the receive will raise an exception if a message is not availble within the timeout.
Expand source code
def receive(self, timeout_millis=None): """ Receive a single message. If a message is not immediately available, this method will block until a new message is available. **Options** * `timeout_millis`: If specified, the receive will raise an exception if a message is not availble within the timeout. """ if timeout_millis is None: return self._consumer.receive() else: _check_type(int, timeout_millis, 'timeout_millis') return self._consumer.receive(timeout_millis)
def redeliver_unacknowledged_messages(self)
-
Redelivers all the unacknowledged messages. In failover mode, the request is ignored if the consumer is not active for the given topic. In shared mode, the consumer's messages to be redelivered are distributed across all the connected consumers. This is a non-blocking call and doesn't throw an exception. In case the connection breaks, the messages are redelivered after reconnect.
Expand source code
def redeliver_unacknowledged_messages(self): """ Redelivers all the unacknowledged messages. In failover mode, the request is ignored if the consumer is not active for the given topic. In shared mode, the consumer's messages to be redelivered are distributed across all the connected consumers. This is a non-blocking call and doesn't throw an exception. In case the connection breaks, the messages are redelivered after reconnect. """ self._consumer.redeliver_unacknowledged_messages()
def resume_message_listener(self)
-
Resume receiving the messages via the message listener. Asynchronously receive all the messages enqueued from the time
pause_message_listener()
was called.Expand source code
def resume_message_listener(self): """ Resume receiving the messages via the message listener. Asynchronously receive all the messages enqueued from the time `pause_message_listener()` was called. """ self._consumer.resume_message_listener()
def seek(self, messageid)
-
Reset the subscription associated with this consumer to a specific message id. The message id can either be a specific message or represent the first or last messages in the topic. Note: this operation can only be done on non-partitioned topics. For these, one can rather perform the seek() on the individual partitions.
Args
message
: The message id for seek.
Expand source code
def seek(self, messageid): """ Reset the subscription associated with this consumer to a specific message id. The message id can either be a specific message or represent the first or last messages in the topic. Note: this operation can only be done on non-partitioned topics. For these, one can rather perform the seek() on the individual partitions. **Args** * `message`: The message id for seek. """ self._consumer.seek(messageid)
def subscription_name(self)
-
Return the subscription name.
Expand source code
def subscription_name(self): """ Return the subscription name. """ return self._consumer.subscription_name()
def topic(self)
-
Return the topic this consumer is subscribed to.
Expand source code
def topic(self): """ Return the topic this consumer is subscribed to. """ return self._consumer.topic()
def unsubscribe(self)
-
Unsubscribe the current consumer from the topic.
This method will block until the operation is completed. Once the consumer is unsubscribed, no more messages will be received and subsequent new messages will not be retained for this consumer.
This consumer object cannot be reused.
Expand source code
def unsubscribe(self): """ Unsubscribe the current consumer from the topic. This method will block until the operation is completed. Once the consumer is unsubscribed, no more messages will be received and subsequent new messages will not be retained for this consumer. This consumer object cannot be reused. """ return self._consumer.unsubscribe()
class Message (*args, **kwargs)
-
Message objects are returned by a consumer, either by calling
receive
or through a listener.Expand source code
class Message: """ Message objects are returned by a consumer, either by calling `receive` or through a listener. """ def data(self): """ Returns object typed bytes with the content of the message. """ return self._message.data() def properties(self): """ Return the properties attached to the message. Properties are application-defined key/value pairs that will be attached to the message. """ return self._message.properties() def partition_key(self): """ Get the partitioning key for the message. """ return self._message.partition_key() def publish_timestamp(self): """ Get the timestamp in milliseconds with the message publish time. """ return self._message.publish_timestamp() def message_id(self): """ The message ID that can be used to refere to this particular message. """ return self._message.message_id()
Methods
def data(self)
-
Returns object typed bytes with the content of the message.
Expand source code
def data(self): """ Returns object typed bytes with the content of the message. """ return self._message.data()
def message_id(self)
-
The message ID that can be used to refere to this particular message.
Expand source code
def message_id(self): """ The message ID that can be used to refere to this particular message. """ return self._message.message_id()
def partition_key(self)
-
Get the partitioning key for the message.
Expand source code
def partition_key(self): """ Get the partitioning key for the message. """ return self._message.partition_key()
def properties(self)
-
Return the properties attached to the message. Properties are application-defined key/value pairs that will be attached to the message.
Expand source code
def properties(self): """ Return the properties attached to the message. Properties are application-defined key/value pairs that will be attached to the message. """ return self._message.properties()
def publish_timestamp(self)
-
Get the timestamp in milliseconds with the message publish time.
Expand source code
def publish_timestamp(self): """ Get the timestamp in milliseconds with the message publish time. """ return self._message.publish_timestamp()
class MessageId (*args, **kwargs)
-
Represents a message id
Expand source code
class MessageId: """ Represents a message id """ 'Represents the earliest message stored in a topic' earliest = _pulsar.MessageId.earliest 'Represents the latest message published on a topic' latest = _pulsar.MessageId.latest def serialize(self): """ Returns a bytes representation of the message id. This bytes sequence can be stored and later deserialized. """ return self._msg_id.serialize() @staticmethod def deserialize(message_id_bytes): """ Deserialize a message id object from a previously serialized bytes sequence. """ return _pulsar.MessageId.deserialize(message_id_bytes)
Class variables
var earliest
-
Represents the latest message published on a topic
var latest
Static methods
def deserialize(message_id_bytes)
-
Deserialize a message id object from a previously serialized bytes sequence.
Expand source code
@staticmethod def deserialize(message_id_bytes): """ Deserialize a message id object from a previously serialized bytes sequence. """ return _pulsar.MessageId.deserialize(message_id_bytes)
Methods
def serialize(self)
-
Returns a bytes representation of the message id. This bytes sequence can be stored and later deserialized.
Expand source code
def serialize(self): """ Returns a bytes representation of the message id. This bytes sequence can be stored and later deserialized. """ return self._msg_id.serialize()
class Producer (*args, **kwargs)
-
The Pulsar message producer, used to publish messages on a topic.
Expand source code
class Producer: """ The Pulsar message producer, used to publish messages on a topic. """ def topic(self): """ Return the topic which producer is publishing to """ return self._producer.topic() def producer_name(self): """ Return the producer name which could have been assigned by the system or specified by the client """ return self._producer.producer_name() def last_sequence_id(self): """ Get the last sequence id that was published by this producer. This represent either the automatically assigned or custom sequence id (set on the `MessageBuilder`) that was published and acknowledged by the broker. After recreating a producer with the same producer name, this will return the last message that was published in the previous producer session, or -1 if there no message was ever published. """ return self._producer.last_sequence_id() def send(self, content, properties=None, partition_key=None, sequence_id=None, replication_clusters=None, disable_replication=False ): """ Publish a message on the topic. Blocks until the message is acknowledged **Args** * `content`: A `bytes` object with the message payload. **Options** * `properties`: A dict of application-defined string properties. * `partition_key`: Sets the partition key for message routing. A hash of this key is used to determine the message's topic partition. * `sequence_id`: Specify a custom sequence id for the message being published. * `replication_clusters`: Override namespace replication clusters. Note that it is the caller's responsibility to provide valid cluster names and that all clusters have been previously configured as topics. Given an empty list, the message will replicate according to the namespace configuration. * `disable_replication`: Do not replicate this message. """ msg = self._build_msg(content, properties, partition_key, sequence_id, replication_clusters, disable_replication) return self._producer.send(msg) def send_async(self, content, callback, properties=None, partition_key=None, sequence_id=None, replication_clusters=None, disable_replication=False ): """ Send a message asynchronously. The `callback` will be invoked once the message has been acknowledged by the broker. Example: #!python def callback(res, msg): print('Message published: %s' % res) producer.send_async(msg, callback) When the producer queue is full, by default the message will be rejected and the callback invoked with an error code. **Args** * `content`: A `bytes` object with the message payload. **Options** * `properties`: A dict of application0-defined string properties. * `partition_key`: Sets the partition key for the message routing. A hash of this key is used to determine the message's topic partition. * `sequence_id`: Specify a custom sequence id for the message being published. * `replication_clusters`: Override namespace replication clusters. Note that it is the caller's responsibility to provide valid cluster names and that all clusters have been previously configured as topics. Given an empty list, the message will replicate per the namespace configuration. * `disable_replication`: Do not replicate this message. """ msg = self._build_msg(content, properties, partition_key, sequence_id, replication_clusters, disable_replication) self._producer.send_async(msg, callback) def close(self): """ Close the producer. """ self._producer.close() def _build_msg(self, content, properties, partition_key, sequence_id, replication_clusters, disable_replication): _check_type(bytes, content, 'content') _check_type_or_none(dict, properties, 'properties') _check_type_or_none(str, partition_key, 'partition_key') _check_type_or_none(int, sequence_id, 'sequence_id') _check_type_or_none(list, replication_clusters, 'replication_clusters') _check_type(bool, disable_replication, 'disable_replication') mb = _pulsar.MessageBuilder() mb.content(content) if properties: for k, v in properties.items(): mb.property(k, v) if partition_key: mb.partition_key(partition_key) if sequence_id: mb.sequence_id(sequence_id) if replication_clusters: mb.replication_clusters(replication_clusters) if disable_replication: mb.disable_replication(disable_replication) return mb.build()
Methods
def close(self)
-
Close the producer.
Expand source code
def close(self): """ Close the producer. """ self._producer.close()
def last_sequence_id(self)
-
Get the last sequence id that was published by this producer.
This represent either the automatically assigned or custom sequence id (set on the
MessageBuilder
) that was published and acknowledged by the broker.After recreating a producer with the same producer name, this will return the last message that was published in the previous producer session, or -1 if there no message was ever published.
Expand source code
def last_sequence_id(self): """ Get the last sequence id that was published by this producer. This represent either the automatically assigned or custom sequence id (set on the `MessageBuilder`) that was published and acknowledged by the broker. After recreating a producer with the same producer name, this will return the last message that was published in the previous producer session, or -1 if there no message was ever published. """ return self._producer.last_sequence_id()
def producer_name(self)
-
Return the producer name which could have been assigned by the system or specified by the client
Expand source code
def producer_name(self): """ Return the producer name which could have been assigned by the system or specified by the client """ return self._producer.producer_name()
def send(self, content, properties=None, partition_key=None, sequence_id=None, replication_clusters=None, disable_replication=False)
-
Publish a message on the topic. Blocks until the message is acknowledged
Args
content
: Abytes
object with the message payload.
Options
properties
: A dict of application-defined string properties.partition_key
: Sets the partition key for message routing. A hash of this key is used to determine the message's topic partition.sequence_id
: Specify a custom sequence id for the message being published.replication_clusters
: Override namespace replication clusters. Note that it is the caller's responsibility to provide valid cluster names and that all clusters have been previously configured as topics. Given an empty list, the message will replicate according to the namespace configuration.disable_replication
: Do not replicate this message.
Expand source code
def send(self, content, properties=None, partition_key=None, sequence_id=None, replication_clusters=None, disable_replication=False ): """ Publish a message on the topic. Blocks until the message is acknowledged **Args** * `content`: A `bytes` object with the message payload. **Options** * `properties`: A dict of application-defined string properties. * `partition_key`: Sets the partition key for message routing. A hash of this key is used to determine the message's topic partition. * `sequence_id`: Specify a custom sequence id for the message being published. * `replication_clusters`: Override namespace replication clusters. Note that it is the caller's responsibility to provide valid cluster names and that all clusters have been previously configured as topics. Given an empty list, the message will replicate according to the namespace configuration. * `disable_replication`: Do not replicate this message. """ msg = self._build_msg(content, properties, partition_key, sequence_id, replication_clusters, disable_replication) return self._producer.send(msg)
def send_async(self, content, callback, properties=None, partition_key=None, sequence_id=None, replication_clusters=None, disable_replication=False)
-
Send a message asynchronously.
The
callback
will be invoked once the message has been acknowledged by the broker.Example
!python
def callback(res, msg): print('Message published: %s' % res)
producer.send_async(msg, callback) When the producer queue is full, by default the message will be rejected and the callback invoked with an error code.
Args
content
: Abytes
object with the message payload.
Options
properties
: A dict of application0-defined string properties.partition_key
: Sets the partition key for the message routing. A hash of this key is used to determine the message's topic partition.sequence_id
: Specify a custom sequence id for the message being published.replication_clusters
: Override namespace replication clusters. Note that it is the caller's responsibility to provide valid cluster names and that all clusters have been previously configured as topics. Given an empty list, the message will replicate per the namespace configuration.disable_replication
: Do not replicate this message.
Expand source code
def send_async(self, content, callback, properties=None, partition_key=None, sequence_id=None, replication_clusters=None, disable_replication=False ): """ Send a message asynchronously. The `callback` will be invoked once the message has been acknowledged by the broker. Example: #!python def callback(res, msg): print('Message published: %s' % res) producer.send_async(msg, callback) When the producer queue is full, by default the message will be rejected and the callback invoked with an error code. **Args** * `content`: A `bytes` object with the message payload. **Options** * `properties`: A dict of application0-defined string properties. * `partition_key`: Sets the partition key for the message routing. A hash of this key is used to determine the message's topic partition. * `sequence_id`: Specify a custom sequence id for the message being published. * `replication_clusters`: Override namespace replication clusters. Note that it is the caller's responsibility to provide valid cluster names and that all clusters have been previously configured as topics. Given an empty list, the message will replicate per the namespace configuration. * `disable_replication`: Do not replicate this message. """ msg = self._build_msg(content, properties, partition_key, sequence_id, replication_clusters, disable_replication) self._producer.send_async(msg, callback)
def topic(self)
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Return the topic which producer is publishing to
Expand source code
def topic(self): """ Return the topic which producer is publishing to """ return self._producer.topic()
class Reader (*args, **kwargs)
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Pulsar topic reader.
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class Reader: """ Pulsar topic reader. """ def topic(self): """ Return the topic this reader is reading from. """ return self._reader.topic() def read_next(self, timeout_millis=None): """ Read a single message. If a message is not immediately available, this method will block until a new message is available. **Options** * `timeout_millis`: If specified, the receive will raise an exception if a message is not available within the timeout. """ if timeout_millis is None: return self._reader.read_next() else: _check_type(int, timeout_millis, 'timeout_millis') return self._reader.read_next(timeout_millis) def has_message_available(self): """ Check if there is any message available to read from the current position. """ return self._reader.has_message_available(); def close(self): """ Close the reader. """ self._reader.close() self._client._consumers.remove(self)
Methods
def close(self)
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Close the reader.
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def close(self): """ Close the reader. """ self._reader.close() self._client._consumers.remove(self)
def has_message_available(self)
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Check if there is any message available to read from the current position.
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def has_message_available(self): """ Check if there is any message available to read from the current position. """ return self._reader.has_message_available();
def read_next(self, timeout_millis=None)
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Read a single message.
If a message is not immediately available, this method will block until a new message is available.
Options
timeout_millis
: If specified, the receive will raise an exception if a message is not available within the timeout.
Expand source code
def read_next(self, timeout_millis=None): """ Read a single message. If a message is not immediately available, this method will block until a new message is available. **Options** * `timeout_millis`: If specified, the receive will raise an exception if a message is not available within the timeout. """ if timeout_millis is None: return self._reader.read_next() else: _check_type(int, timeout_millis, 'timeout_millis') return self._reader.read_next(timeout_millis)
def topic(self)
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Return the topic this reader is reading from.
Expand source code
def topic(self): """ Return the topic this reader is reading from. """ return self._reader.topic()