KafkaConsumer — kafka-python 2.0.2-dev documentation

*topics (str) – optional list of topics to subscribe to. If not set, call subscribe() or assign() before consuming records.

• bootstrap_servers – ‘host[:port]’ string (or list of ‘host[:port]’
  strings) that the consumer should contact to bootstrap initial
  cluster metadata. This does not have to be the full node list.
  It just needs to have at least one broker that will respond to a
  Metadata API Request. Default port is 9092. If no servers are
  specified, will default to localhost:9092.
• client_id (str) – A name for this client. This string is passed in
  each request to servers and can be used to identify specific
  server-side log entries that correspond to this client. Also
  submitted to GroupCoordinator for logging with respect to
  consumer group administration. Default: ‘kafka-python-{version}’
• group_id (str or None) – The name of the consumer group to join for dynamic
  partition assignment (if enabled), and to use for fetching and
  committing offsets. If None, auto-partition assignment (via
  group coordinator) and offset commits are disabled.
  Default: None
• key_deserializer (callable) – Any callable that takes a
  raw message key and returns a deserialized key.
• value_deserializer (callable) – Any callable that takes a
  raw message value and returns a deserialized value.
• fetch_min_bytes (int) – Minimum amount of data the server should
  return for a fetch request, otherwise wait up to
  fetch_max_wait_ms for more data to accumulate. Default: 1.
• fetch_max_wait_ms (int) – The maximum amount of time in milliseconds
  the server will block before answering the fetch request if
  there isn’t sufficient data to immediately satisfy the
  requirement given by fetch_min_bytes. Default: 500.
• fetch_max_bytes (int) – The maximum amount of data the server should
  return for a fetch request. This is not an absolute maximum, if the
  first message in the first non-empty partition of the fetch is
  larger than this value, the message will still be returned to
  ensure that the consumer can make progress. NOTE: consumer performs
  fetches to multiple brokers in parallel so memory usage will depend
  on the number of brokers containing partitions for the topic.
  Supported Kafka version >= 0.10.1.0. Default: 52428800 (50 MB).
• max_partition_fetch_bytes (int) – The maximum amount of data
  per-partition the server will return. The maximum total memory
  used for a request = #partitions * max_partition_fetch_bytes.
  This size must be at least as large as the maximum message size
  the server allows or else it is possible for the producer to
  send messages larger than the consumer can fetch. If that
  happens, the consumer can get stuck trying to fetch a large
  message on a certain partition. Default: 1048576.
• request_timeout_ms (int) – Client request timeout in milliseconds.
  Default: 305000.
• retry_backoff_ms (int) – Milliseconds to backoff when retrying on
  errors. Default: 100.
• reconnect_backoff_ms (int) – The amount of time in milliseconds to
  wait before attempting to reconnect to a given host.
  Default: 50.
• reconnect_backoff_max_ms (int) – The maximum amount of time in
  milliseconds to backoff/wait when reconnecting to a broker that has
  repeatedly failed to connect. If provided, the backoff per host
  will increase exponentially for each consecutive connection
  failure, up to this maximum. Once the maximum is reached,
  reconnection attempts will continue periodically with this fixed
  rate. To avoid connection storms, a randomization factor of 0.2
  will be applied to the backoff resulting in a random range between
  20% below and 20% above the computed value. Default: 1000.
• max_in_flight_requests_per_connection (int) – Requests are pipelined
  to kafka brokers up to this number of maximum requests per
  broker connection. Default: 5.
• auto_offset_reset (str) – A policy for resetting offsets on
  OffsetOutOfRange errors: ‘earliest’ will move to the oldest
  available message, ‘latest’ will move to the most recent. Any
  other value will raise the exception. Default: ‘latest’.
• enable_auto_commit (bool) – If True , the consumer’s offset will be
  periodically committed in the background. Default: True.
• auto_commit_interval_ms (int) – Number of milliseconds between automatic
  offset commits, if enable_auto_commit is True. Default: 5000.
• default_offset_commit_callback (callable) – Called as
  callback(offsets, response) response will be either an Exception
  or an OffsetCommitResponse struct. This callback can be used to
  trigger custom actions when a commit request completes.
• check_crcs (bool) – Automatically check the CRC32 of the records
  consumed. This ensures no on-the-wire or on-disk corruption to
  the messages occurred. This check adds some overhead, so it may
  be disabled in cases seeking extreme performance. Default: True
• metadata_max_age_ms (int) – The period of time in milliseconds after
  which we force a refresh of metadata, even if we haven’t seen any
  partition leadership changes to proactively discover any new
  brokers or partitions. Default: 300000
• partition_assignment_strategy (list) – List of objects to use to
  distribute partition ownership amongst consumer instances when
  group management is used.
  Default: [RangePartitionAssignor, RoundRobinPartitionAssignor]
• max_poll_records (int) – The maximum number of records returned in a
  single call to

  poll()

  . Default: 500

• max_poll_interval_ms (int) – The maximum delay between invocations of
  

  poll()

  when using consumer group
  management. This places an upper bound on the amount of time that
  the consumer can be idle before fetching more records. If
  

  poll()

  is not called before expiration
  of this timeout, then the consumer is considered failed and the
  group will rebalance in order to reassign the partitions to another
  member. Default 300000

• session_timeout_ms (int) – The timeout used to detect failures when
  using Kafka’s group management facilities. The consumer sends
  periodic heartbeats to indicate its liveness to the broker. If
  no heartbeats are received by the broker before the expiration of
  this session timeout, then the broker will remove this consumer
  from the group and initiate a rebalance. Note that the value must
  be in the allowable range as configured in the broker configuration
  by group.min.session.timeout.ms and group.max.session.timeout.ms.
  Default: 10000
• heartbeat_interval_ms (int) – The expected time in milliseconds
  between heartbeats to the consumer coordinator when using
  Kafka’s group management facilities. Heartbeats are used to ensure
  that the consumer’s session stays active and to facilitate
  rebalancing when new consumers join or leave the group. The
  value must be set lower than session_timeout_ms, but typically
  should be set no higher than 1/3 of that value. It can be
  adjusted even lower to control the expected time for normal
  rebalances. Default: 3000
• receive_buffer_bytes (int) – The size of the TCP receive buffer
  (SO_RCVBUF) to use when reading data. Default: None (relies on
  system defaults). The java client defaults to 32768.
• send_buffer_bytes (int) – The size of the TCP send buffer
  (SO_SNDBUF) to use when sending data. Default: None (relies on
  system defaults). The java client defaults to 131072.
• socket_options (list) – List of tuple-arguments to socket.setsockopt
  to apply to broker connection sockets. Default:
  [(socket.IPPROTO_TCP, socket.TCP_NODELAY, 1)]
• consumer_timeout_ms (int) – number of milliseconds to block during
  message iteration before raising StopIteration (i.e., ending the
  iterator). Default block forever [float(‘inf’)].
• security_protocol (str) – Protocol used to communicate with brokers.
  Valid values are: PLAINTEXT, SSL, SASL_PLAINTEXT, SASL_SSL.
  Default: PLAINTEXT.
• ssl_context (ssl.SSLContext) – Pre-configured SSLContext for wrapping
  socket connections. If provided, all other ssl_* configurations
  will be ignored. Default: None.
• ssl_check_hostname (bool) – Flag to configure whether ssl handshake
  should verify that the certificate matches the brokers hostname.
  Default: True.
• ssl_cafile (str) – Optional filename of ca file to use in certificate
  verification. Default: None.
• ssl_certfile (str) – Optional filename of file in pem format containing
  the client certificate, as well as any ca certificates needed to
  establish the certificate’s authenticity. Default: None.
• ssl_keyfile (str) – Optional filename containing the client private key.
  Default: None.
• ssl_password (str) – Optional password to be used when loading the
  certificate chain. Default: None.
• ssl_crlfile (str) – Optional filename containing the CRL to check for
  certificate expiration. By default, no CRL check is done. When
  providing a file, only the leaf certificate will be checked against
  this CRL. The CRL can only be checked with Python 3.4+ or 2.7.9+.
  Default: None.
• ssl_ciphers (str) – optionally set the available ciphers for ssl
  connections. It should be a string in the OpenSSL cipher list
  format. If no cipher can be selected (because compile-time options
  or other configuration forbids use of all the specified ciphers),
  an ssl.SSLError will be raised. See ssl.SSLContext.set_ciphers
• api_version (tuple) –

  Specify which Kafka API version to use. If set to
  None, the client will attempt to infer the broker version by probing
  various APIs. Different versions enable different functionality.

  Examples

  (0, 9) enables full group coordination features with automatic

  partition assignment and rebalancing,

  (0, 8, 2) enables kafka-storage offset commits with manual

  partition assignment only,

  (0, 8, 1) enables zookeeper-storage offset commits with manual

  partition assignment only,

  (0, 8, 0) enables basic functionality but requires manual

  partition assignment and offset management.

  Default: None

• api_version_auto_timeout_ms (int) – number of milliseconds to throw a
  timeout exception from the constructor when checking the broker
  api version. Only applies if api_version set to None.
• connections_max_idle_ms – Close idle connections after the number of
  milliseconds specified by this config. The broker closes idle
  connections after connections.max.idle.ms, so this avoids hitting
  unexpected socket disconnected errors on the client.
  Default: 540000
• metric_reporters (list) – A list of classes to use as metrics reporters.
  Implementing the AbstractMetricsReporter interface allows plugging
  in classes that will be notified of new metric creation. Default: []
• metrics_num_samples (int) – The number of samples maintained to compute
  metrics. Default: 2
• metrics_sample_window_ms (int) – The maximum age in milliseconds of
  samples used to compute metrics. Default: 30000
• selector (selectors.BaseSelector) – Provide a specific selector
  implementation to use for I/O multiplexing.
  Default: selectors.DefaultSelector
• exclude_internal_topics (bool) – Whether records from internal topics
  (such as offsets) should be exposed to the consumer. If set to True
  the only way to receive records from an internal topic is
  subscribing to it. Requires 0.10+ Default: True
• sasl_mechanism (str) – Authentication mechanism when security_protocol
  is configured for SASL_PLAINTEXT or SASL_SSL. Valid values are:
  PLAIN, GSSAPI, OAUTHBEARER, SCRAM-SHA-256, SCRAM-SHA-512.
• sasl_plain_username (str) – username for sasl PLAIN and SCRAM authentication.
  Required if sasl_mechanism is PLAIN or one of the SCRAM mechanisms.
• sasl_plain_password (str) – password for sasl PLAIN and SCRAM authentication.
  Required if sasl_mechanism is PLAIN or one of the SCRAM mechanisms.
• sasl_kerberos_service_name (str) – Service name to include in GSSAPI
  sasl mechanism handshake. Default: ‘kafka’
• sasl_kerberos_domain_name (str) – kerberos domain name to use in GSSAPI
  sasl mechanism handshake. Default: one of bootstrap servers
• sasl_oauth_token_provider (AbstractTokenProvider) – OAuthBearer token provider
  instance. (See kafka.oauth.abstract). Default: None