rdkafka

• Update MSRV to 1.70
• Fix test dependency on docker compose.
• Address wakeup races introduced by pivoting to the event API.
• Remove testing for old Kafka versions (before 3.0). Add tests for 3.7.

• Update BaseConsumer::poll to return None when handling rebalance or offset commit events.

• Pivot the library from using librdkafka's callback interface to using the event interface. The public API of the crate does not change.

• Update bundled librdkafka to 2.3.0.
• Add cargo enforcement of MSRV of 1.61.
• Derives serde::Serialize on Statistics

• Update bundled librdkafka to 2.2.0.

• Breaking change. Change signature for seek_partitions. Following librdkafka, individual partition errors should be reported in the per-partition error field of TopicPartitionList elements.

• Add interface to specify custom partitioners by extending ProducerContext trait with capability to return optional custom partitioner.
• Add seek_partitions to consumer.

• Breaking change. Pass KafkaError to rebalance hooks instead of human-readable string representation.

• Support for unassigning static partitions by passing null to rdsys::rd_kafka_assign and expose the feature as unassign in base_consumer

• Expose rdsys::rd_kafka_incremental_assign and rdsys::rd_kafka_incremental_unassign in base_consumer for incremental changes to static assignments

• Breaking change. util::get_rdkafka_version now returns (i32, String). Previously, it returned (u16, String) which would silently truncate the hex representation of the version:

  Interpreted as hex MM.mm.rr.xx:

  MM = Major mm = minor rr = revision xx = pre-release id (0xff is the final release) E.g.: 0x010902ff = 1.9.2

• Add the AdminClient::delete_groups method, which deletes consumer groups from a Kafka cluster (#510).

  Thanks, @andrewinci.

• Add support for the purge API, that allows retreiving messages that were queued for production when shutting down. It is automatically called on Drop. Fixes leaking associated data (futures...).

• Breaking change. Pass through errors from librdkafka in BaseProducer::flush, StreamProducer::flush, and FutureProducer::flush.

  Thanks, @cjubb39.

• Breaking change. Only provide NaiveRuntime if the naive-runtime feature is enabled. This elides a dependency on futures-executor when the naive-runtime feature is disabled.

• Breaking change. Remove the deprecated StreamConsumer::start method. Use the more clearly named StreamConsumer::stream method instead.

• Breaking change. Rework the Headers trait to distinguish between headers with null values and headers with empty values. The Headers::get and Headers::get_as methods now return a Header struct with the following definition:

  pub struct Header<'a, V> {
      pub key: &'a str,
      pub value: Option<V>,
  }
  

  Previously, these methods operated in terms of key–value pair (&str, &[u8]).

  These methods now panic if presented with an out-of-bounds index. This simplifies their usage in the common case where the index is known to be valid. Use the new Headers::try_get and Headers::try_get_as methods if you need the old behavior of returning None if the index is invalid.

• Rename the OwnedHeader::add method to OwnedHeader::insert, for parity with the equivalent method for the map types in std::collection and to avoid confusion with the add method of the std::ops::Add trait. The method now takes the Header type mentioned above as an argument, rather than the key and value as separate arguments.

• Add the Headers::iter method to iterate over all message headers in order.

• Add the PartitionQueue::set_nonempty_callback method to register a callback for a specific partition queue that will run when that queue becomes nonempty. This is a more flexible replacement for the ConsumerContext::message_queue_nonempty_callback method that was removed in the last release.

• In BaseConsumer::rebalance_protocol and StreamConsumer::rebalance_protocol, handle null return values from the underlying librdkakfa API (#417). This avoids an occasional segfault in the rebalance callback.

  Thanks, @bruceg.

• Add a tracing feature which, when enabled, emits log messages using the tracing crate rather than the log crate.

• Add support for the OAUTHBEARER SASL authentication mechanism via the new ClientContext::ENABLE_REFRESH_OAUTH_TOKEN constant and the new ClientContext::generate_oauth_token method.

  Thanks, @jsurany-bloomberg.

• Add the StreamConsumer::split_partition_queue method to mirror BaseConsumer::split_partition_queue (#411).

  Thanks to @davidblewett, @duarten, and @nemosupremo for contributing to the implementation.

• Breaking change. Remove the StreamConsumerContext type and the ConsumerContext::message_queue_nonempty_callback method. These were essentially implementation details of StreamConsumer that had leaked into the public API. The vast majority of users should be unaffected.

• Breaking change. Remove the type parameters from the MessageStream type.

• Breaking change. Add the received TopicPartitionList to the Rebalance::Revoke variant, which is useful when using incremental cooperative rebalancing (#398).

• Avoid crashing if librdkafka invokes the commit callback with a null topic partition list (#406).

  Thanks, @thijsc.

• Add the new statistics fields in librdkafka v1.7.0 to the various statistics types. The new fields are:

  • Partition::consumer_lag_stored
  • Broker::txidle
  • Broker::rxidle
  • Statistics::age

• Breaking change. Change the type of the following statistics fields from i64 to u64 to reflect the signedness of the upstream types:

  • Statistics::msg_cnt
  • Statistics::msg_size
  • Statistics::msg_max
  • Statistics::msg_size_max
  • Broker::tx
  • Broker::txbytes
  • Broker::txretries
  • Broker::req_timeouts
  • Broker::rx
  • Broker::rxbytes
  • Broker::rxerrs
  • Broker::rxcorriderrs
  • Broker::rxpartial
  • Broker::zbuf_grow
  • Broker::buf_grow
  • Broker::wakeups
  • Broker::msgq_bytes
  • Broker::xmit_msgq_bytes
  • Broker::fetchq_size
  • Partition::txmsgs
  • Partition::txbytes
  • Partition::rxmsgs
  • Partition::rxbytes
  • Partition::msgs
  • Partition::rx_ver_drops
  • Partition::acked_msgid

• Add the ClientContext::stats_raw method to consume the JSON-encoded statistics from librdkafka. The default implementation calls ClientContext::stats with the decoded statistics.

• Add the Default trait to the statistics types: Statistics, Broker, Window, TopicPartition, Topic, Partition, ConsumerGroup, and ExactlyOnceSemantics (#410).

  Thanks, @scanterog.

• Add the Debug trait to DefaultClientContext and DefaultConsumerContext (#401).

  Thanks, @DXist.

<a name="0.27.0"></a>

• Allow offset 0 in Offset::to_raw.

  Thanks, [@roignpar].

• Fix a segfault when calling Consumer::position on a consumer that was improperly configured (#360).

• Provide a mutable accessor (Message::payload_mut) for a message's payload (#95).

• Implement std::iter::Extend<(String, String)> and std::iter::FromIterator<(String, String) for ClientConfig (#367).

  Thanks, @djKooks.

• Breaking change. Change Consumer::store_offset to accept the topic, partition, and offset directly (#89, #368). The old API, which took a BorrowedMessage, is still accessible as Consumer::store_offset_from_message.

• Support incremental cooperative rebalancing (#364). There are two changes of note:

  • The addition of Consumer::rebalance_protocol to determine the rebalance protocol in use.

  • The modification of the default rebalance callback (ConsumerContext::rebalance) to perform incremental assignments and unassignments when the rebalance protocol in use is [RebalanceProtocol::Cooperative].

  Thanks, @SreeniIO.

• Support reading and writing commit metadata via TopicPartitionListElem::metadata and TopicPartitionListElem::set_metadata, respectively (#391).

  Thanks, @phaazon.

<a name="0.26.0"></a>

• Fix compilation for the aarch64 target.

• Add an inner method to StreamConsumerContext to enable access to the underlying context.

  Thanks, @marcelo140.

• Mark the KafkaError enum as [non-exhaustive] so that future additions to the enum will not be considered breaking changes.

<a name="0.25.0"></a>

• Add support for transactional producers. The new methods are Producer::init_transactions, Producer::begin_transaction, Producer::commit_transaction, Producer::abort_transaction, and Producer::send_offsets_to_transaction.

  Thanks to @roignpar for the implementation.

• Breaking change. Rename RDKafkaError to RDKafkaErrorCode. This makes space for the new RDKafkaError type, which mirrors the rd_kafka_error_t type added to librdkafka in v1.4.0.

  This change was made to reduce long-term confusion by ensuring the types in rust-rdkafka map to types in librdkafka as directly as possible. The maintainers apologize for the difficulty in upgrading through this change.

• Breaking change. Rework the consumer APIs to fix several bugs and design warts:

  • Rename StreamConsumer::start to StreamConsumer::stream, though the former name will be retained as a deprecated alias for one release to ease the transition. The new name better reflects that the method is a cheap operation that can be called repeatedly and in multiple threads simultaneously.

  • Remove the StreamConsumer::start_with and StreamConsumer::start_with_runtime methods.

    There is no replacement in rust-rdkafka itself for the no_message_error parameter. If you need this message, use a downstream combinator like tokio_stream::StreamExt::timeout.

    There is no longer a need for the poll_interval parameter to these methods. Message delivery is now entirely event driven, so no time-based polling occurs.

    To specify an AsyncRuntime besides the default, specify the desired runtime type as the new R parameter of StreamConsumer when you create it.

  • Remove the Consumer::get_base_consumer method, as accessing the BaseConsumer that underlied a StreamConsumer was dangerous.

  • Return an &Arc<C> from Client::context rather than an &C. This is expected to cause very little breakage in practice.

  • Move the BaseConsumer::context method to the Consumer trait, so that it is available when using the StreamConsumer as well.

• Breaking change. Rework the producer APIs to fix several design warts:

  • Remove the FutureProducer::send_with_runtime method. Use the send method instead. The AsyncRuntime to use is determined by the new R type parameter to FutureProducer, which you can specify when you create the producer.

    This change makes the FutureProducer mirror the redesigned StreamConsumer.

    This change should have no impact on users who use the default runtime.

  • Move the producer::base_producer::{ProducerContext, DefaultProducerContext} types out of the base_producer module and into the producer module directly, to match the consumer module layout.

  • Move the client, in_flight_count, and flush methods inherent to all producers to a new Producer trait. This trait is analogous to the Consumer trait.

• Breaking change. Calls to BaseConsumer::assign deactivate any partition queues previously created with BaseConsumer::split_partition_queue. You will need to re-split all partition queues after every call to assign.

  This is due to an upstream change in librdkafka. See edenhill/librdkafka#3231 for details.

• Breaking change. Several TopicPartitionList-related methods now return Result<T, KafkaError> rather than T:

  • TopicPartitionListElem::set_offset
  • TopicPartitionList::from_topic_map
  • TopicPartitionList::add_partition_offset
  • TopicPartitionList::set_all_offsets

  This was necessary to properly throw errors when an Offset passed to one of these methods is representable in Rust but not in C.

• Support end-relative offsets via Offset::OffsetTail.

• Fix stalls when using multiple MessageStreams simultaneously.

  Thanks to @Marwes for discovering the issue and contributing the initial fix.

• Add a convenience method, StreamConsumer::recv, to yield the next message from a stream.

  Thanks again to @Marwes.

• Add a new implementation of AsyncRuntime called NaiveRuntime that does not depend on Tokio.

  This runtime has poor performance, but is necessary to make the crate compile when the tokio feature is disabled.

• Add the ClientConfig::get and ClientConfig::remove methods to retrieve and remove configuration parameters that were set with ClientConfig::set.

• Breaking change. Change the key and value parameters of the ClientConfig::set method to accept any type that implements Into<String>, rather than only &str.

  This is technically a breaking change as values of type &&str are no longer accepted, but this is expected to be a rare case.

  Thanks, @koushiro.

• Add the NativeClientConfig::get method, which reflects librdkafka's view of a parameter value. Unlike ClientConfig::get, this method is capable of surfacing librdkafka's default value for a parameter.

• Add the missing req field, which counts the number of requests of each type that librdkafka has sent, to the Statistics struct. Thanks, @pablosichert!

<a name="0.24.0"></a>

• Breaking change. Introduce a dependency on Tokio for the StreamConsumer in its default configuration. The new implementation is more efficient and does not require a background thread and an extra futures executor.

• Introduce the StreamConsumer::start_with_runtime and FutureProducer::send_with_runtime methods. These methods are identical to their respective non-_with_runtime counterparts, except that they take an additional AsyncRuntime generic parameter that permits using an asynchronous runtime besides Tokio.

  For an example of using rdkafka with the smol runtime, see the new smol runtime example.

• Breaking change. Remove the StreamConsumer::stop method. To stop a StreamConsumer after calling start, simply drop the resulting MessageStream.

• Breaking change. Overhaul the FutureProducer::send method. The old implementation incorrectly blocked asynchronous tasks with std::thread::sleep and the block_ms parameter did not behave as documented.

  The new implementation:

  • changes the block_ms: i64 parameter to queue_timeout: impl Into<Timeout>, to better match how timeouts are handled elsewhere in the rust-rdkafka API,

  • depends on Tokio, in order to retry enqueuing after a time interval without using std::thread::sleep,

  • returns an opaque future that borrows its input, rather than a DeliveryFuture with no internal references,

  • simplifies the output type of the returned future from Result<OwnedDeliveryResult, oneshot::Canceled> to OwnedDeliveryResult.

  Thanks to @FSMaxB-dooshop for discovering the issue and contributing the initial fix.

• Breaking change. Remove the util::duration_to_millis function. This functionality has been available in the standard library as std::time::Duration::as_millis for over a year.

• Introduce the BaseConsumer::split_partition_queue method to allow reading messages from partitions independently of one another.

• Implement Clone, Copy, and Debug for CommitMode.

• Decouple versioning of rdkafka-sys from rdkafka. rdkafka-sys now has its own changelog and will follow SemVer conventions. (#211)

<a name="0.23.1"></a>

• Fix build on docs.rs.

<a name="0.23.0"></a>

• Upgrade to the async/await ecosystem, including std::future::Future, v0.3 of the futures crate, and v0.2 of Tokio. The minimum supported Rust version is now Rust 1.39. Special thanks to @sd2k and @dbcfd. (#187)

  The main difference is that functions that previously returned

  futures01::Future<Item = T, Error = E>
  

  now return:

  std::future::Future<Output = Result<T, E>>
  

  In the special case when the error was (), the new signature is further simplified to:

  std::future::Future<Output = T>
  

  Functions that return future::Streams have had the analogous transformation applied.

• Implement Send and Sync on BorrowedMessage, so that holding a reference to a BorrowedMessage across an await point is possible. (#190)

• Implement Sync on OwnedHeaders, which applies transitively to OwnedMessage, so that holding a reference to an OwnedMessage across an await point is possible. (#203)

• Bump librdkafka to v1.3.0. (#202)

• Change the signature of ConsumerContext::commit_callback so that the offsets are passed via a safe TopicPartitionList struct, and not a raw *mut rdkafka_sys::RDKafkaPartitionList pointer. Thanks, @scrogson! (#198).

• Fix CMake build on Windows when debug information is enabled (#194).

<a name="0.22.0"></a>

• Add a client for Kafka's Admin API, which allows actions like creating and deleting Kafka topics and changing configuration parameters. (#122)
• Fix compliation on ARM, and ensure it stays fixed by adding an ARM builder to CI. (#134, #162)
• Stop automatically generating librdkafka bindings. Platform-independent bindings are now checked in to the repository. (#163)
• Move zstd compression support behind the zstd feature flag. (#163)
• Remove build-time dependency on bindgen, clang, and libclang. (#163)
• Support Consumer::pause and Consumer::resume. (#167)
• Expose the message_queue_nonempty callback, which allows clients to put their poll thread to sleep and be woken up when new data arrives. (#164)
• Implement IntoOpaque for Arc<T>. (#171)
• Add Consumer::seek method. (#172)
• Support building with Microsoft Visual C++ (MSVC) on Windows. (#176)
• Bump librdkafka to v1.2.2. (#177)
• Run tests against multiple Kafka versions in CI. (#182)
• Standardize feature names. All feature names now use hyphens instead of underscores, as is conventional, though the old names remain for backwards compatibility. (#183)
• Optionalize libz via a new libz feature. The new feature is a default feature for backwards compatibility. (#183)
• Better attempt to make build systems agree on what version of a dependency to compile and link against, and document this hazard. (#183)

<a name="0.21.0"></a>

• Add librdkafka 1.0 support
• Automatically generate librdkafka bindings
• Use updated tokio version in asynchronous_processing example

<a name="0.20.0"></a>

• Add FreeBSD support
• Add offsets_for_times method
• Add committed_offsets method

<a name="0.19.0"></a>

• Fix ordering of generics in FutureProducer::send

<a name="0.18.1"></a>

• Add method for storing multiple offsets

<a name="0.18.0"></a>

• Upgrade librdkafka to 0.11.6

<a name="0.17.0"></a>

• Add missing documentation warning.
• Add new experimental producer API. Instead of taking key, value and timestamp directly, producers now get them in a ProducerRecord which allows to specify optional arguments using the builder pattern.
• Add message headers support.
• Upgrade tokio-core to tokio in async example, remove futures-cpupool.
• MessageStream is now Send and Sync

<a name="0.16.0"></a>

• Upgrade librdkafka to 0.11.4

<a name="0.15.0"></a>

• Added iterator interface to the BaseConsumer.
• Change timeout to more rust-idiomatic Option<Duration>.
• Add external_lz4 feature to use external lz4 library instead of the one one built in librdkafka. Disable by default.
• Mark all from_ptr methods as unsafe.
• Remove Timestamp::from_system_time and implement From trait instead.
• Rename Context to ClientContext.
• Rename Empty(...)Context to Default(...)Context.
• Use default type parameters for the context of Client, producers and consumers with Default(...)Context set as the default one.
• Increase default buffer size in StreamConsumer from 0 to 10 to reduce context switching.

<a name="0.14.1"></a>

• Upgrade to librdkafka 0.11.3
• Add send_copy_result method to FutureProducer

<a name="0.14.0"></a>

Features

• Make PollingProducer methods public
• Rename PollingProducer to ThreadedProducer

Refactoring

• Remove TopicConfig since librdkafka supports default topic configuration directly in the top level configuration
• Rename DeliveryContext into DeliveryOpaque
• Add IntoOpaque trait to support different opaque types.

Bugs

• Fix regression in producer error reporting (#65)

<a name="0.13.0"></a>

Refactoring

• Split producer.rs into multiple files
• Both producers now return the original message after failure
• BaseConsumer returns an Option<Result> instead of Result<Option>

Features

• Upgrade to librdkafka 0.11.1
• Enable dynamic linking via feature
• Refactor BaseConsumer, which now implements the Consumer trait directly
• A negative timestamp will now automatically be reported as NonAvailable timestamp
• Point rdkafka-sys to latest librdkafka master branch
• Add producer.flush and producer.in_flight_count
• Add max block time for FutureProducer

Bugs

• Fix memory leak during consumer error reporting
• Fix memory leak during producer error reporting

<a name="0.12.0"></a>

Features

• Upgrade librdkafka to 0.11.0.
• FutureProducer::send_copy will now return a DeliveryFuture direcly.
• TPL entries now also export errors.
• KafkaError is now Clone and Eq.

Bugs

• Fix flaky tests.

<a name="0.11.1"></a>

Features

• Support direct creation of OwnedMessages.

<a name="0.11.0"></a>

Features

• The topic partition list object from librdkafka is now completely accessible from Rust.
• The test suite will now run both unit tests and integration tests in valgrind, and it will also check for memory leaks.
• rdkafka-sys will use the system librdkafka if it's already installed.
• rdkafka-sys will verify that the crate version corresponds to the librdkafka version during the build.
• Timestamp is now Copy.
• Message has been renamed to BorrowedMessage. Borrowed messages can be transformed into owned messages. Both implement the new Message trait.
• Improved error enumerations.

Bugs

• Fix memory access bug in statistics callback.
• Fix memory leak in topic partition list.
• Messages lifetime is now explicit (issue #48)

<a name="0.10.0"></a>

Features

• Consumer commit callback
• Add configurable poll timeout
• Add special error code for message not received within poll time
• Add topic field for messages
• Make the topic partition list optional for consumer commit
• Add store_offset to consumer
• Add at-least-once delivery example

<a name="0.9.1"></a>

Features

• OpenSSL dependency optional
• librdkafka 0.9.5

<a name="0.9.0"></a>

Bugs

• Fix termination sequence

Features

• Integration tests running in docker and valgrind
• Producer topics are not needed anymore

<a name="0.8.1"></a>

Bugs

• Implement Clone for BaseProducerTopic

Features

<a name="0.8.0"></a>

Features

• Add timestamp support
• librdkafka 0.9.4
• Add client statistics callback and parsing

<a name="0.7.0"></a>

Features

• Asynchronous message processing example based on tokio
• More metadata for consumers
• Watermark API
• First iteration of integration test suite