librdkafka
The Apache Kafka C/C++ client library
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Configuration properties

Global configuration properties

Property C/P Range Default Importance Description
builtin.features * gzip, snappy, sasl, regex, lz4, sasl_plain, plugins low Indicates the builtin features for this build of librdkafka. An application can either query this value or attempt to set it with its list of required features to check for library support.
*Type: CSV flags*
client.id * rdkafka low Client identifier.
*Type: string*
metadata.broker.list * high Initial list of brokers as a CSV list of broker host or host:port. The application may also use rd_kafka_brokers_add() to add brokers during runtime.
*Type: string*
bootstrap.servers * high Alias for metadata.broker.list: Initial list of brokers as a CSV list of broker host or host:port. The application may also use rd_kafka_brokers_add() to add brokers during runtime.
*Type: string*
message.max.bytes * 1000 .. 1000000000 1000000 medium Maximum Kafka protocol request message size. Due to differing framing overhead between protocol versions the producer is unable to reliably enforce a strict max message limit at produce time and may exceed the maximum size by one message in protocol ProduceRequests, the broker will enforce the the topic's max.message.bytes limit (see Apache Kafka documentation).
*Type: integer*
message.copy.max.bytes * 0 .. 1000000000 65535 low Maximum size for message to be copied to buffer. Messages larger than this will be passed by reference (zero-copy) at the expense of larger iovecs.
*Type: integer*
receive.message.max.bytes * 1000 .. 2147483647 100000000 medium Maximum Kafka protocol response message size. This serves as a safety precaution to avoid memory exhaustion in case of protocol hickups. This value must be at least fetch.max.bytes + 512 to allow for protocol overhead; the value is adjusted automatically unless the configuration property is explicitly set.
*Type: integer*
max.in.flight.requests.per.connection * 1 .. 1000000 1000000 low Maximum number of in-flight requests per broker connection. This is a generic property applied to all broker communication, however it is primarily relevant to produce requests. In particular, note that other mechanisms limit the number of outstanding consumer fetch request per broker to one.
*Type: integer*
max.in.flight * 1 .. 1000000 1000000 low Alias for max.in.flight.requests.per.connection: Maximum number of in-flight requests per broker connection. This is a generic property applied to all broker communication, however it is primarily relevant to produce requests. In particular, note that other mechanisms limit the number of outstanding consumer fetch request per broker to one.
*Type: integer*
metadata.request.timeout.ms * 10 .. 900000 60000 low Non-topic request timeout in milliseconds. This is for metadata requests, etc.
*Type: integer*
topic.metadata.refresh.interval.ms * -1 .. 3600000 300000 low Period of time in milliseconds at which topic and broker metadata is refreshed in order to proactively discover any new brokers, topics, partitions or partition leader changes. Use -1 to disable the intervalled refresh (not recommended). If there are no locally referenced topics (no topic objects created, no messages produced, no subscription or no assignment) then only the broker list will be refreshed every interval but no more often than every 10s.
*Type: integer*
metadata.max.age.ms * 1 .. 86400000 900000 low Metadata cache max age. Defaults to topic.metadata.refresh.interval.ms * 3
*Type: integer*
topic.metadata.refresh.fast.interval.ms * 1 .. 60000 250 low When a topic loses its leader a new metadata request will be enqueued with this initial interval, exponentially increasing until the topic metadata has been refreshed. This is used to recover quickly from transitioning leader brokers.
*Type: integer*
topic.metadata.refresh.fast.cnt * 0 .. 1000 10 low DEPRECATED No longer used.
*Type: integer*
topic.metadata.refresh.sparse * true, false true low Sparse metadata requests (consumes less network bandwidth)
*Type: boolean*
topic.blacklist * low Topic blacklist, a comma-separated list of regular expressions for matching topic names that should be ignored in broker metadata information as if the topics did not exist.
*Type: pattern list*
debug * generic, broker, topic, metadata, feature, queue, msg, protocol, cgrp, security, fetch, interceptor, plugin, consumer, admin, eos, mock, all medium A comma-separated list of debug contexts to enable. Detailed Producer debugging: broker,topic,msg. Consumer: consumer,cgrp,topic,fetch
*Type: CSV flags*
socket.timeout.ms * 10 .. 300000 60000 low Default timeout for network requests. Producer: ProduceRequests will use the lesser value of socket.timeout.ms and remaining message.timeout.ms for the first message in the batch. Consumer: FetchRequests will use fetch.wait.max.ms + socket.timeout.ms. Admin: Admin requests will use socket.timeout.ms or explicitly set rd_kafka_AdminOptions_set_operation_timeout() value.
*Type: integer*
socket.blocking.max.ms * 1 .. 60000 1000 low DEPRECATED No longer used.
*Type: integer*
socket.send.buffer.bytes * 0 .. 100000000 0 low Broker socket send buffer size. System default is used if 0.
*Type: integer*
socket.receive.buffer.bytes * 0 .. 100000000 0 low Broker socket receive buffer size. System default is used if 0.
*Type: integer*
socket.keepalive.enable * true, false false low Enable TCP keep-alives (SO_KEEPALIVE) on broker sockets
*Type: boolean*
socket.nagle.disable * true, false false low Disable the Nagle algorithm (TCP_NODELAY) on broker sockets.
*Type: boolean*
socket.max.fails * 0 .. 1000000 1 low Disconnect from broker when this number of send failures (e.g., timed out requests) is reached. Disable with 0. WARNING: It is highly recommended to leave this setting at its default value of 1 to avoid the client and broker to become desynchronized in case of request timeouts. NOTE: The connection is automatically re-established.
*Type: integer*
broker.address.ttl * 0 .. 86400000 1000 low How long to cache the broker address resolving results (milliseconds).
*Type: integer*
broker.address.family * any, v4, v6 any low Allowed broker IP address families: any, v4, v6
*Type: enum value*
reconnect.backoff.jitter.ms * 0 .. 3600000 0 low DEPRECATED No longer used. See reconnect.backoff.ms and reconnect.backoff.max.ms.
*Type: integer*
reconnect.backoff.ms * 0 .. 3600000 100 medium The initial time to wait before reconnecting to a broker after the connection has been closed. The time is increased exponentially until reconnect.backoff.max.ms is reached. -25% to +50% jitter is applied to each reconnect backoff. A value of 0 disables the backoff and reconnects immediately.
*Type: integer*
reconnect.backoff.max.ms * 0 .. 3600000 10000 medium The maximum time to wait before reconnecting to a broker after the connection has been closed.
*Type: integer*
statistics.interval.ms * 0 .. 86400000 0 high librdkafka statistics emit interval. The application also needs to register a stats callback using rd_kafka_conf_set_stats_cb(). The granularity is 1000ms. A value of 0 disables statistics.
*Type: integer*
enabled_events * 0 .. 2147483647 0 low See rd_kafka_conf_set_events()
*Type: integer*
error_cb * low Error callback (set with rd_kafka_conf_set_error_cb())
*Type: see dedicated API*
throttle_cb * low Throttle callback (set with rd_kafka_conf_set_throttle_cb())
*Type: see dedicated API*
stats_cb * low Statistics callback (set with rd_kafka_conf_set_stats_cb())
*Type: see dedicated API*
log_cb * low Log callback (set with rd_kafka_conf_set_log_cb())
*Type: see dedicated API*
log_level * 0 .. 7 6 low Logging level (syslog(3) levels)
*Type: integer*
log.queue * true, false false low Disable spontaneous log_cb from internal librdkafka threads, instead enqueue log messages on queue set with rd_kafka_set_log_queue() and serve log callbacks or events through the standard poll APIs. NOTE: Log messages will linger in a temporary queue until the log queue has been set.
*Type: boolean*
log.thread.name * true, false true low Print internal thread name in log messages (useful for debugging librdkafka internals)
*Type: boolean*
log.connection.close * true, false true low Log broker disconnects. It might be useful to turn this off when interacting with 0.9 brokers with an aggressive connection.max.idle.ms value.
*Type: boolean*
background_event_cb * low Background queue event callback (set with rd_kafka_conf_set_background_event_cb())
*Type: see dedicated API*
socket_cb * low Socket creation callback to provide race-free CLOEXEC
*Type: see dedicated API*
connect_cb * low Socket connect callback
*Type: see dedicated API*
closesocket_cb * low Socket close callback
*Type: see dedicated API*
open_cb * low File open callback to provide race-free CLOEXEC
*Type: see dedicated API*
opaque * low Application opaque (set with rd_kafka_conf_set_opaque())
*Type: see dedicated API*
default_topic_conf * low Default topic configuration for automatically subscribed topics
*Type: see dedicated API*
internal.termination.signal * 0 .. 128 0 low Signal that librdkafka will use to quickly terminate on rd_kafka_destroy(). If this signal is not set then there will be a delay before rd_kafka_wait_destroyed() returns true as internal threads are timing out their system calls. If this signal is set however the delay will be minimal. The application should mask this signal as an internal signal handler is installed.
*Type: integer*
api.version.request * true, false true high Request broker's supported API versions to adjust functionality to available protocol features. If set to false, or the ApiVersionRequest fails, the fallback version broker.version.fallback will be used. NOTE: Depends on broker version >=0.10.0. If the request is not supported by (an older) broker the broker.version.fallback fallback is used.
*Type: boolean*
api.version.request.timeout.ms * 1 .. 300000 10000 low Timeout for broker API version requests.
*Type: integer*
api.version.fallback.ms * 0 .. 604800000 0 medium Dictates how long the broker.version.fallback fallback is used in the case the ApiVersionRequest fails. NOTE: The ApiVersionRequest is only issued when a new connection to the broker is made (such as after an upgrade).
*Type: integer*
broker.version.fallback * 0.10.0 medium Older broker versions (before 0.10.0) provide no way for a client to query for supported protocol features (ApiVersionRequest, see api.version.request) making it impossible for the client to know what features it may use. As a workaround a user may set this property to the expected broker version and the client will automatically adjust its feature set accordingly if the ApiVersionRequest fails (or is disabled). The fallback broker version will be used for api.version.fallback.ms. Valid values are: 0.9.0, 0.8.2, 0.8.1, 0.8.0. Any other value >= 0.10, such as 0.10.2.1, enables ApiVersionRequests.
*Type: string*
security.protocol * plaintext, sasl_plaintext plaintext high Protocol used to communicate with brokers.
*Type: enum value*
sasl.mechanisms * GSSAPI high SASL mechanism to use for authentication. Supported: GSSAPI, PLAIN, SCRAM-SHA-256, SCRAM-SHA-512, OAUTHBEARER. NOTE: Despite the name only one mechanism must be configured.
*Type: string*
sasl.mechanism * GSSAPI high Alias for sasl.mechanisms: SASL mechanism to use for authentication. Supported: GSSAPI, PLAIN, SCRAM-SHA-256, SCRAM-SHA-512, OAUTHBEARER. NOTE: Despite the name only one mechanism must be configured.
*Type: string*
sasl.kerberos.service.name * kafka low Kerberos principal name that Kafka runs as, not including /hostname@REALM
*Type: string*
sasl.kerberos.principal * kafkaclient low This client's Kerberos principal name. (Not supported on Windows, will use the logon user's principal).
*Type: string*
sasl.kerberos.kinit.cmd * kinit -R -t "%{sasl.kerberos.keytab}" -k %{sasl.kerberos.principal} || kinit -t "%{sasl.kerberos.keytab}" -k %{sasl.kerberos.principal} low Shell command to refresh or acquire the client's Kerberos ticket. This command is executed on client creation and every sasl.kerberos.min.time.before.relogin (0=disable). %{config.prop.name} is replaced by corresponding config object value.
*Type: string*
sasl.kerberos.keytab * low Path to Kerberos keytab file. This configuration property is only used as a variable in sasl.kerberos.kinit.cmd as ... -t "%{sasl.kerberos.keytab}".
*Type: string*
sasl.kerberos.min.time.before.relogin * 0 .. 86400000 60000 low Minimum time in milliseconds between key refresh attempts. Disable automatic key refresh by setting this property to 0.
*Type: integer*
sasl.username * high SASL username for use with the PLAIN and SASL-SCRAM-.. mechanisms
*Type: string*
sasl.password * high SASL password for use with the PLAIN and SASL-SCRAM-.. mechanism
*Type: string*
plugin.library.paths * low List of plugin libraries to load (; separated). The library search path is platform dependent (see dlopen(3) for Unix and LoadLibrary() for Windows). If no filename extension is specified the platform-specific extension (such as .dll or .so) will be appended automatically.
*Type: string*
interceptors * low Interceptors added through rd_kafka_conf_interceptor_add_..() and any configuration handled by interceptors.
*Type: see dedicated API*
group.id C high Client group id string. All clients sharing the same group.id belong to the same group.
*Type: string*
group.instance.id C medium Enable static group membership. Static group members are able to leave and rejoin a group within the configured session.timeout.ms without prompting a group rebalance. This should be used in combination with a larger session.timeout.ms to avoid group rebalances caused by transient unavailability (e.g. process restarts). Requires broker version >= 2.3.0.
*Type: string*
partition.assignment.strategy C range,roundrobin medium Name of partition assignment strategy to use when elected group leader assigns partitions to group members.
*Type: string*
session.timeout.ms C 1 .. 3600000 10000 high Client group session and failure detection timeout. The consumer sends periodic heartbeats (heartbeat.interval.ms) to indicate its liveness to the broker. If no hearts are received by the broker for a group member within the session timeout, the broker will remove the consumer from the group and trigger a rebalance. The allowed range is configured with the broker configuration properties group.min.session.timeout.ms and group.max.session.timeout.ms. Also see max.poll.interval.ms.
*Type: integer*
heartbeat.interval.ms C 1 .. 3600000 3000 low Group session keepalive heartbeat interval.
*Type: integer*
group.protocol.type C consumer low Group protocol type
*Type: string*
coordinator.query.interval.ms C 1 .. 3600000 600000 low How often to query for the current client group coordinator. If the currently assigned coordinator is down the configured query interval will be divided by ten to more quickly recover in case of coordinator reassignment.
*Type: integer*
max.poll.interval.ms C 1 .. 86400000 300000 high Maximum allowed time between calls to consume messages (e.g., rd_kafka_consumer_poll()) for high-level consumers. If this interval is exceeded the consumer is considered failed and the group will rebalance in order to reassign the partitions to another consumer group member. Warning: Offset commits may be not possible at this point. Note: It is recommended to set enable.auto.offset.store=false for long-time processing applications and then explicitly store offsets (using offsets_store()) after message processing, to make sure offsets are not auto-committed prior to processing has finished. The interval is checked two times per second. See KIP-62 for more information.
*Type: integer*
enable.auto.commit C true, false true high Automatically and periodically commit offsets in the background. Note: setting this to false does not prevent the consumer from fetching previously committed start offsets. To circumvent this behaviour set specific start offsets per partition in the call to assign().
*Type: boolean*
auto.commit.interval.ms C 0 .. 86400000 5000 medium The frequency in milliseconds that the consumer offsets are committed (written) to offset storage. (0 = disable). This setting is used by the high-level consumer.
*Type: integer*
enable.auto.offset.store C true, false true high Automatically store offset of last message provided to application. The offset store is an in-memory store of the next offset to (auto-)commit for each partition.
*Type: boolean*
queued.min.messages C 1 .. 10000000 100000 medium Minimum number of messages per topic+partition librdkafka tries to maintain in the local consumer queue.
*Type: integer*
queued.max.messages.kbytes C 1 .. 2097151 1048576 medium Maximum number of kilobytes per topic+partition in the local consumer queue. This value may be overshot by fetch.message.max.bytes. This property has higher priority than queued.min.messages.
*Type: integer*
fetch.wait.max.ms C 0 .. 300000 100 low Maximum time the broker may wait to fill the response with fetch.min.bytes.
*Type: integer*
fetch.message.max.bytes C 1 .. 1000000000 1048576 medium Initial maximum number of bytes per topic+partition to request when fetching messages from the broker. If the client encounters a message larger than this value it will gradually try to increase it until the entire message can be fetched.
*Type: integer*
max.partition.fetch.bytes C 1 .. 1000000000 1048576 medium Alias for fetch.message.max.bytes: Initial maximum number of bytes per topic+partition to request when fetching messages from the broker. If the client encounters a message larger than this value it will gradually try to increase it until the entire message can be fetched.
*Type: integer*
fetch.max.bytes C 0 .. 2147483135 52428800 medium Maximum amount of data the broker shall return for a Fetch request. Messages are fetched in batches by the consumer and if the first message batch in the first non-empty partition of the Fetch request is larger than this value, then the message batch will still be returned to ensure the consumer can make progress. The maximum message batch size accepted by the broker is defined via message.max.bytes (broker config) or max.message.bytes (broker topic config). fetch.max.bytes is automatically adjusted upwards to be at least message.max.bytes (consumer config).
*Type: integer*
fetch.min.bytes C 1 .. 100000000 1 low Minimum number of bytes the broker responds with. If fetch.wait.max.ms expires the accumulated data will be sent to the client regardless of this setting.
*Type: integer*
fetch.error.backoff.ms C 0 .. 300000 500 medium How long to postpone the next fetch request for a topic+partition in case of a fetch error.
*Type: integer*
offset.store.method C none, file, broker broker low DEPRECATED Offset commit store method: 'file' - DEPRECATED: local file store (offset.store.path, et.al), 'broker' - broker commit store (requires Apache Kafka 0.8.2 or later on the broker).
*Type: enum value*
isolation.level C read_uncommitted, read_committed read_committed high Controls how to read messages written transactionally: read_committed - only return transactional messages which have been committed. read_uncommitted - return all messages, even transactional messages which have been aborted.
*Type: enum value*
consume_cb C low Message consume callback (set with rd_kafka_conf_set_consume_cb())
*Type: see dedicated API*
rebalance_cb C low Called after consumer group has been rebalanced (set with rd_kafka_conf_set_rebalance_cb())
*Type: see dedicated API*
offset_commit_cb C low Offset commit result propagation callback. (set with rd_kafka_conf_set_offset_commit_cb())
*Type: see dedicated API*
enable.partition.eof C true, false false low Emit RD_KAFKA_RESP_ERR__PARTITION_EOF event whenever the consumer reaches the end of a partition.
*Type: boolean*
check.crcs C true, false false medium Verify CRC32 of consumed messages, ensuring no on-the-wire or on-disk corruption to the messages occurred. This check comes at slightly increased CPU usage.
*Type: boolean*
client.rack * low A rack identifier for this client. This can be any string value which indicates where this client is physically located. It corresponds with the broker config broker.rack.
*Type: string*
transactional.id P high Enables the transactional producer. The transactional.id is used to identify the same transactional producer instance across process restarts. It allows the producer to guarantee that transactions corresponding to earlier instances of the same producer have been finalized prior to starting any new transactions, and that any zombie instances are fenced off. If no transactional.id is provided, then the producer is limited to idempotent delivery (if enable.idempotence is set). Requires broker version >= 0.11.0.
*Type: string*
transaction.timeout.ms P 1000 .. 2147483647 60000 medium The maximum amount of time in milliseconds that the transaction coordinator will wait for a transaction status update from the producer before proactively aborting the ongoing transaction. If this value is larger than the transaction.max.timeout.ms setting in the broker, the init_transactions() call will fail with ERR_INVALID_TRANSACTION_TIMEOUT. The transaction timeout automatically adjusts message.timeout.ms and socket.timeout.ms, unless explicitly configured in which case they must not exceed the transaction timeout (socket.timeout.ms must be at least 100ms lower than transaction.timeout.ms). This is also the default timeout value if no timeout (-1) is supplied to the transactional API methods.
*Type: integer*
enable.idempotence P true, false false high When set to true, the producer will ensure that messages are successfully produced exactly once and in the original produce order. The following configuration properties are adjusted automatically (if not modified by the user) when idempotence is enabled: max.in.flight.requests.per.connection=5 (must be less than or equal to 5), retries=INT32_MAX (must be greater than 0), acks=all, queuing.strategy=fifo. Producer instantation will fail if user-supplied configuration is incompatible.
*Type: boolean*
enable.gapless.guarantee P true, false false low EXPERIMENTAL: subject to change or removal. When set to true, any error that could result in a gap in the produced message series when a batch of messages fails, will raise a fatal error (ERR__GAPLESS_GUARANTEE) and stop the producer. Messages failing due to message.timeout.ms are not covered by this guarantee. Requires enable.idempotence=true.
*Type: boolean*
queue.buffering.max.messages P 1 .. 10000000 100000 high Maximum number of messages allowed on the producer queue. This queue is shared by all topics and partitions.
*Type: integer*
queue.buffering.max.kbytes P 1 .. 2147483647 1048576 high Maximum total message size sum allowed on the producer queue. This queue is shared by all topics and partitions. This property has higher priority than queue.buffering.max.messages.
*Type: integer*
queue.buffering.max.ms P 0 .. 900000 0.5 high Delay in milliseconds to wait for messages in the producer queue to accumulate before constructing message batches (MessageSets) to transmit to brokers. A higher value allows larger and more effective (less overhead, improved compression) batches of messages to accumulate at the expense of increased message delivery latency.
*Type: float*
linger.ms P 0 .. 900000 0.5 high Alias for queue.buffering.max.ms: Delay in milliseconds to wait for messages in the producer queue to accumulate before constructing message batches (MessageSets) to transmit to brokers. A higher value allows larger and more effective (less overhead, improved compression) batches of messages to accumulate at the expense of increased message delivery latency.
*Type: float*
message.send.max.retries P 0 .. 10000000 2 high How many times to retry sending a failing Message. Note: retrying may cause reordering unless enable.idempotence is set to true.
*Type: integer*
retries P 0 .. 10000000 2 high Alias for message.send.max.retries: How many times to retry sending a failing Message. Note: retrying may cause reordering unless enable.idempotence is set to true.
*Type: integer*
retry.backoff.ms P 1 .. 300000 100 medium The backoff time in milliseconds before retrying a protocol request.
*Type: integer*
queue.buffering.backpressure.threshold P 1 .. 1000000 1 low The threshold of outstanding not yet transmitted broker requests needed to backpressure the producer's message accumulator. If the number of not yet transmitted requests equals or exceeds this number, produce request creation that would have otherwise been triggered (for example, in accordance with linger.ms) will be delayed. A lower number yields larger and more effective batches. A higher value can improve latency when using compression on slow machines.
*Type: integer*
compression.codec P none, gzip, snappy, lz4 none medium compression codec to use for compressing message sets. This is the default value for all topics, may be overridden by the topic configuration property compression.codec.
*Type: enum value*
compression.type P none, gzip, snappy, lz4 none medium Alias for compression.codec: compression codec to use for compressing message sets. This is the default value for all topics, may be overridden by the topic configuration property compression.codec.
*Type: enum value*
batch.num.messages P 1 .. 1000000 10000 medium Maximum number of messages batched in one MessageSet. The total MessageSet size is also limited by message.max.bytes.
*Type: integer*
delivery.report.only.error P true, false false low Only provide delivery reports for failed messages.
*Type: boolean*
dr_cb P low Delivery report callback (set with rd_kafka_conf_set_dr_cb())
*Type: see dedicated API*
dr_msg_cb P low Delivery report callback (set with rd_kafka_conf_set_dr_msg_cb())
*Type: see dedicated API*

Topic configuration properties

Property C/P Range Default Importance Description
request.required.acks P -1 .. 1000 -1 high This field indicates the number of acknowledgements the leader broker must receive from ISR brokers before responding to the request: 0=Broker does not send any response/ack to client, *-1* or all=Broker will block until message is committed by all in sync replicas (ISRs). If there are less than min.insync.replicas (broker configuration) in the ISR set the produce request will fail.
*Type: integer*
acks P -1 .. 1000 -1 high Alias for request.required.acks: This field indicates the number of acknowledgements the leader broker must receive from ISR brokers before responding to the request: 0=Broker does not send any response/ack to client, *-1* or all=Broker will block until message is committed by all in sync replicas (ISRs). If there are less than min.insync.replicas (broker configuration) in the ISR set the produce request will fail.
*Type: integer*
request.timeout.ms P 1 .. 900000 5000 medium The ack timeout of the producer request in milliseconds. This value is only enforced by the broker and relies on request.required.acks being != 0.
*Type: integer*
message.timeout.ms P 0 .. 2147483647 300000 high Local message timeout. This value is only enforced locally and limits the time a produced message waits for successful delivery. A time of 0 is infinite. This is the maximum time librdkafka may use to deliver a message (including retries). Delivery error occurs when either the retry count or the message timeout are exceeded. The message timeout is automatically adjusted to transaction.timeout.ms if transactional.id is configured.
*Type: integer*
delivery.timeout.ms P 0 .. 2147483647 300000 high Alias for message.timeout.ms: Local message timeout. This value is only enforced locally and limits the time a produced message waits for successful delivery. A time of 0 is infinite. This is the maximum time librdkafka may use to deliver a message (including retries). Delivery error occurs when either the retry count or the message timeout are exceeded. The message timeout is automatically adjusted to transaction.timeout.ms if transactional.id is configured.
*Type: integer*
queuing.strategy P fifo, lifo fifo low EXPERIMENTAL: subject to change or removal. DEPRECATED Producer queuing strategy. FIFO preserves produce ordering, while LIFO prioritizes new messages.
*Type: enum value*
produce.offset.report P true, false false low DEPRECATED No longer used.
*Type: boolean*
partitioner P consistent_random high Partitioner: random - random distribution, consistent - CRC32 hash of key (Empty and NULL keys are mapped to single partition), consistent_random - CRC32 hash of key (Empty and NULL keys are randomly partitioned), murmur2 - Java Producer compatible Murmur2 hash of key (NULL keys are mapped to single partition), murmur2_random - Java Producer compatible Murmur2 hash of key (NULL keys are randomly partitioned. This is functionally equivalent to the default partitioner in the Java Producer.), fnv1a - FNV-1a hash of key (NULL keys are mapped to single partition), fnv1a_random - FNV-1a hash of key (NULL keys are randomly partitioned).
*Type: string*
partitioner_cb P low Custom partitioner callback (set with rd_kafka_topic_conf_set_partitioner_cb())
*Type: see dedicated API*
msg_order_cmp P low EXPERIMENTAL: subject to change or removal. DEPRECATED Message queue ordering comparator (set with rd_kafka_topic_conf_set_msg_order_cmp()). Also see queuing.strategy.
*Type: see dedicated API*
opaque * low Application opaque (set with rd_kafka_topic_conf_set_opaque())
*Type: see dedicated API*
compression.codec P none, gzip, snappy, lz4, inherit inherit high Compression codec to use for compressing message sets. inherit = inherit global compression.codec configuration.
*Type: enum value*
compression.type P none, gzip, snappy, lz4 none medium Alias for compression.codec: compression codec to use for compressing message sets. This is the default value for all topics, may be overridden by the topic configuration property compression.codec.
*Type: enum value*
compression.level P -1 .. 12 -1 medium Compression level parameter for algorithm selected by configuration property compression.codec. Higher values will result in better compression at the cost of more CPU usage. Usable range is algorithm-dependent: [0-9] for gzip; [0-12] for lz4; only 0 for snappy; -1 = codec-dependent default compression level.
*Type: integer*
auto.commit.enable C true, false true low DEPRECATED [LEGACY PROPERTY: This property is used by the simple legacy consumer only. When using the high-level KafkaConsumer, the global enable.auto.commit property must be used instead]. If true, periodically commit offset of the last message handed to the application. This committed offset will be used when the process restarts to pick up where it left off. If false, the application will have to call rd_kafka_offset_store() to store an offset (optional). NOTE: There is currently no zookeeper integration, offsets will be written to broker or local file according to offset.store.method.
*Type: boolean*
enable.auto.commit C true, false true low DEPRECATED Alias for auto.commit.enable: [LEGACY PROPERTY: This property is used by the simple legacy consumer only. When using the high-level KafkaConsumer, the global enable.auto.commit property must be used instead]. If true, periodically commit offset of the last message handed to the application. This committed offset will be used when the process restarts to pick up where it left off. If false, the application will have to call rd_kafka_offset_store() to store an offset (optional). NOTE: There is currently no zookeeper integration, offsets will be written to broker or local file according to offset.store.method.
*Type: boolean*
auto.commit.interval.ms C 10 .. 86400000 60000 high [LEGACY PROPERTY: This setting is used by the simple legacy consumer only. When using the high-level KafkaConsumer, the global auto.commit.interval.ms property must be used instead]. The frequency in milliseconds that the consumer offsets are committed (written) to offset storage.
*Type: integer*
auto.offset.reset C smallest, earliest, beginning, largest, latest, end, error largest high Action to take when there is no initial offset in offset store or the desired offset is out of range: 'smallest','earliest' - automatically reset the offset to the smallest offset, 'largest','latest' - automatically reset the offset to the largest offset, 'error' - trigger an error which is retrieved by consuming messages and checking 'message->err'.
*Type: enum value*
offset.store.path C . low DEPRECATED Path to local file for storing offsets. If the path is a directory a filename will be automatically generated in that directory based on the topic and partition. File-based offset storage will be removed in a future version.
*Type: string*
offset.store.sync.interval.ms C -1 .. 86400000 -1 low DEPRECATED fsync() interval for the offset file, in milliseconds. Use -1 to disable syncing, and 0 for immediate sync after each write. File-based offset storage will be removed in a future version.
*Type: integer*
offset.store.method C file, broker broker low DEPRECATED Offset commit store method: 'file' - DEPRECATED: local file store (offset.store.path, et.al), 'broker' - broker commit store (requires "group.id" to be configured and Apache Kafka 0.8.2 or later on the broker.).
*Type: enum value*
consume.callback.max.messages C 0 .. 1000000 0 low Maximum number of messages to dispatch in one rd_kafka_consume_callback*() call (0 = unlimited)
*Type: integer*

C/P legend: C = Consumer, P = Producer, * = both