pulsar.Consumer

class documentation

class Consumer: (source)

Pulsar consumer.

Examples

import pulsar

client = pulsar.Client('pulsar://localhost:6650')
consumer = client.subscribe('my-topic', 'my-subscription')
while True:
    msg = consumer.receive()
    try:
        print("Received message '{}' id='{}'".format(msg.data(), msg.message_id()))
        consumer.acknowledge(msg)
    except Exception:
        consumer.negative_acknowledge(msg)
client.close()

Method	`acknowledge`	Acknowledge the reception of a single message.
Method	`acknowledge_cumulative`	Acknowledge the reception of all the messages in the stream up to (and including) the provided message.
Method	`batch_receive`	Batch receiving messages.
Method	`close`	Close the consumer.
Method	`get_last_message_id`	Get the last message id.
Method	`is_connected`	Check if the consumer is connected or not.
Method	`negative_acknowledge`	Acknowledge the failure to process a single message.
Method	`pause_message_listener`	Pause receiving messages via the `message_listener` until `resume_message_listener()` is called.
Method	`receive`	Receive a single message.
Method	`redeliver_unacknowledged_messages`	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...
Method	`resume_message_listener`	Resume receiving the messages via the message listener. Asynchronously receive all the messages enqueued from the time `pause_message_listener()` was called.
Method	`seek`	Reset the subscription associated with this consumer to a specific message id or publish timestamp. The message id can either be a specific message or represent the first or last messages in the topic. ...
Method	`subscription_name`	Return the subscription name.
Method	`topic`	Return the topic this consumer is subscribed to.
Method	`unsubscribe`	Unsubscribe the current consumer from the topic.

def acknowledge(self, message): (source) ¶

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.

Parameters
message:`Message`, `_pulsar.Message`, `_pulsar.MessageId`	The received message or message id.
Raises
`OperationNotSupported`	if `message` is not allowed to acknowledge

def acknowledge_cumulative(self, message): (source) ¶

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.

Parameters
message	The received message or message id.
Raises
`CumulativeAcknowledgementNotAllowedError`	if the consumer type is ConsumerType.KeyShared or ConsumerType.Shared

def batch_receive(self): (source) ¶

Batch receiving messages.

This calls blocks until has enough messages or wait timeout, more details to see {@link BatchReceivePolicy}.

def close(self): (source) ¶

Close the consumer.

def get_last_message_id(self): (source) ¶

Get the last message id.

def is_connected(self): (source) ¶

Check if the consumer is connected or not.

def negative_acknowledge(self, message): (source) ¶

Acknowledge the failure to process a single message.

When a message is "negatively acked" it will be marked for redelivery after some fixed delay. The delay is configurable when constructing the consumer with {@link ConsumerConfiguration#setNegativeAckRedeliveryDelayMs}.

This call is not blocking.

Parameters
message	The received message or message id.

def pause_message_listener(self): (source) ¶

Pause receiving messages via the message_listener until resume_message_listener() is called.

def receive(self, timeout_millis=None): (source) ¶

Receive a single message.

If a message is not immediately available, this method will block until a new message is available.

Parameters
timeout_millis:`int`, optional	If specified, the receiver will raise an exception if a message is not available within the timeout.

def redeliver_unacknowledged_messages(self): (source) ¶

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.

def resume_message_listener(self): (source) ¶

Resume receiving the messages via the message listener. Asynchronously receive all the messages enqueued from the time pause_message_listener() was called.

def seek(self, messageid): (source) ¶

Reset the subscription associated with this consumer to a specific message id or publish timestamp. 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.

Parameters
messageid	The message id for seek, OR an integer event time to seek to

def subscription_name(self): (source) ¶

Return the subscription name.

def topic(self): (source) ¶

Return the topic this consumer is subscribed to.

def unsubscribe(self): (source) ¶

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.