Welcome to Confluent's Python client for Apache Kafka documentation

Indices and tables

confluent_kafka --- Confluent's Python client for Apache Kafka










Logical offset constants:

  • OFFSET_BEGINNING - Beginning of partition (oldest offset)
  • OFFSET_END - End of partition (next offset)
  • OFFSET_STORED - Use stored/committed offset
  • OFFSET_INVALID - Invalid/Default offset



Configuration of producer and consumer instances is performed by providing a dict of configuration properties to the instance constructor, e.g.:

conf = {'bootstrap.servers': 'mybroker.com',
        'group.id': 'mygroup', 'session.timeout.ms': 6000,
        'on_commit': my_commit_callback,
        'auto.offset.reset': 'earliest'}
consumer = confluent_kafka.Consumer(conf)

The supported configuration values are dictated by the underlying librdkafka C library. For the full range of configuration properties please consult librdkafka's documentation: https://github.com/edenhill/librdkafka/blob/master/CONFIGURATION.md

The Python bindings also provide some additional configuration properties:

  • default.topic.config: value is a dict of client topic-level configuration properties that are applied to all used topics for the instance. **DEPRECATED: ** topic configuration should now be specified in the global top-level configuration.

  • error_cb(kafka.KafkaError): Callback for generic/global error events. This callback is served upon calling client.poll() or producer.flush().

  • throttle_cb(confluent_kafka.ThrottleEvent): Callback for throttled request reporting. This callback is served upon calling client.poll() or producer.flush().

  • stats_cb(json_str): Callback for statistics data. This callback is triggered by poll() or flush every statistics.interval.ms (needs to be configured separately). Function argument json_str is a str instance of a JSON document containing statistics data. This callback is served upon calling client.poll() or producer.flush(). See https://github.com/edenhill/librdkafka/wiki/Statistics" for more information.

  • on_delivery(kafka.KafkaError, kafka.Message) (Producer): value is a Python function reference that is called once for each produced message to indicate the final delivery result (success or failure). This property may also be set per-message by passing callback=callable (or on_delivery=callable) to the confluent_kafka.Producer.produce() function. Currently message headers are not supported on the message returned to the callback. The msg.headers() will return None even if the original message had headers set. This callback is served upon calling producer.poll() or producer.flush().

  • on_commit(kafka.KafkaError, list(kafka.TopicPartition)) (Consumer): Callback used to indicate success or failure of asynchronous and automatic commit requests. This callback is served upon calling consumer.poll(). Is not triggered for synchronous commits.

  • logger=logging.Handler kwarg: forward logs from the Kafka client to the provided logging.Handler instance. To avoid spontaneous calls from non-Python threads the log messages will only be forwarded when client.poll() or producer.flush() are called. For example:

    mylogger = logging.getLogger()
    producer = confluent_kafka.Producer({'bootstrap.servers': 'mybroker.com'}, logger=mylogger)