Kafka-python

Consumers
* Avoid resending FetchRequests that are pending on internal queue
* Log debug messages when skipping fetched messages due to offset checks
* KAFKA-3013: Include topic-partition in exception for expired batches
* KAFKA-3318: clean up consumer logging and error messages
* Improve unknown coordinator error handling
* Improve auto-commit error handling when group_id is None
* Add paused() API (zackdever PR 602)
* Add default_offset_commit_callback to KafkaConsumer DEFAULT_CONFIGS

Producers
<none>

Clients
* Support SSL connections
* Use selectors module for non-blocking IO
* Refactor KafkaClient connection management
* Fix AttributeError in __del__
* SimpleClient: catch errors thrown by _get_leader_for_partition (zackdever PR 606)

Documentation
* Fix serializer/deserializer examples in README
* Update max.block.ms docstring
* Remove errant next(consumer) from consumer documentation
* Add producer.flush() to usage docs

Internals
* Add initial metrics implementation (zackdever PR 637)
* KAFKA-2136: support Fetch and Produce v1 (throttle_time_ms)
* Use version-indexed lists for request/response protocol structs (dpkp PR 630)
* Split kafka.common into kafka.structs and kafka.errors
* Handle partial socket send() (dpkp PR 611)
* Fix windows support (dpkp PR 603)
* IPv6 support (TimEvens PR 615; Roguelazer PR 642)

Consumers
* Improve KafkaConsumer Heartbeat handling (dpkp PR 583)
* Fix KafkaConsumer.position bug (stefanth PR 578)
* Raise TypeError when partition is not a TopicPartition (dpkp PR 587)
* KafkaConsumer.poll should sleep to prevent tight-loops (dpkp PR 597)

Producers
* Fix producer threading bug that can crash sender (dpkp PR 590)
* Fix bug in producer buffer pool reallocation (dpkp PR 585)
* Remove spurious warnings when closing sync SimpleProducer (twm PR 567)
* Fix FutureProduceResult.await() on python2.6 (dpkp)
* Add optional timeout parameter to KafkaProducer.flush() (dpkp)
* KafkaProducer Optimizations (zackdever PR 598)

Clients
* Improve error handling in SimpleClient.load_metadata_for_topics (dpkp)
* Improve handling of KafkaClient.least_loaded_node failure (dpkp PR 588)

Documentation
* Fix KafkaError import error in docs (shichao-an PR 564)
* Fix serializer / deserializer examples (scribu PR 573)

Internals
* Update to Kafka 0.9.0.1 for integration testing
* Fix ifr.future.failure in conn.py (mortenlj PR 566)
* Improve Zookeeper / Kafka Fixture management (dpkp)

Consumers
* Add RangePartitionAssignor (and use as default); add assignor tests (dpkp PR 550)
* Make sure all consumers are in same generation before stopping group test
* Verify node ready before sending offset fetch request from coordinator
* Improve warning when offset fetch request returns unknown topic / partition

Producers
* Warn if pending batches failed during flush
* Fix concurrency bug in RecordAccumulator.ready()
* Fix bug in SimpleBufferPool memory condition waiting / timeout
* Support batch_size = 0 in producer buffers (dpkp PR 558)
* Catch duplicate batch.done() calls [e.g., maybe_expire then a response errback]

Clients

Documentation
* Improve kafka.cluster docstrings
* Migrate load_example.py to KafkaProducer / KafkaConsumer

Internals
* Don't override system rcvbuf or sndbuf unless configured explicitly (dpkp PR 557)
* Some attributes may not exist in __del__ if we failed assertions
* Break up some circular references and close client wake pipes on __del__ (aisch PR 554)

This release includes significant code changes. Users of older kafka-python
versions are encouraged to test upgrades before deploying to production as
some interfaces and configuration options have changed.

Users of SimpleConsumer / SimpleProducer / SimpleClient (formerly KafkaClient)
from prior releases should migrate to KafkaConsumer / KafkaProducer. Low-level
APIs (Simple*) are no longer being actively maintained and will be removed in a
future release.

For comprehensive API documentation, please see python help() / docstrings,
kafka-python.readthedocs.org, or run `tox -e docs` from source to build
documentation locally.

Consumers
* KafkaConsumer re-written to emulate the new 0.9 kafka consumer (java client)
and support coordinated consumer groups (feature requires >= 0.9.0.0 brokers)

* Methods no longer available:

* configure [initialize a new consumer instead]
* set_topic_partitions [use subscribe() or assign()]
* fetch_messages [use poll() or iterator interface]
* get_partition_offsets
* offsets [use committed(partition)]
* task_done [handled internally by auto-commit; or commit offsets manually]

* Configuration changes (consistent with updated java client):

* lots of new configuration parameters -- see docs for details
* auto_offset_reset: previously values were 'smallest' or 'largest', now
values are 'earliest' or 'latest'
* fetch_wait_max_ms is now fetch_max_wait_ms
* max_partition_fetch_bytes is now max_partition_fetch_bytes
* deserializer_class is now value_deserializer and key_deserializer
* auto_commit_enable is now enable_auto_commit
* auto_commit_interval_messages was removed
* socket_timeout_ms was removed
* refresh_leader_backoff_ms was removed

* SimpleConsumer and MultiProcessConsumer are now deprecated and will be removed
in a future release. Users are encouraged to migrate to KafkaConsumer.

Producers
* new producer class: KafkaProducer. Exposes the same interface as official java client.
Async by default; returned future.get() can be called for synchronous blocking
* SimpleProducer is now deprecated and will be removed in a future release. Users are
encouraged to migrate to KafkaProducer.

Clients
* synchronous KafkaClient renamed to SimpleClient. For backwards compatibility, you
will get a SimpleClient via `from kafka import KafkaClient`. This will change in
a future release.
* All client calls use non-blocking IO under the hood.
* Add probe method check_version() to infer broker versions.

Documentation
* Updated README and sphinx documentation to address new classes.
* Docstring improvements to make python help() easier to use.

Internals
* Old protocol stack is deprecated. It has been moved to kafka.protocol.legacy
and may be removed in a future release.
* Protocol layer re-written using Type classes, Schemas and Structs (modeled on
the java client).
* Add support for LZ4 compression (including broken framing header checksum).

Consumers
* Initial support for consumer coordinator: offsets only (toddpalino PR 420)
* Allow blocking until some messages are received in SimpleConsumer (saaros PR 457)
* Support subclass config changes in KafkaConsumer (zackdever PR 446)
* Support retry semantics in MultiProcessConsumer (barricadeio PR 456)
* Support partition_info in MultiProcessConsumer (scrapinghub PR 418)
* Enable seek() to an absolute offset in SimpleConsumer (haosdent PR 412)
* Add KafkaConsumer.close() (ucarion PR 426)

Producers
* Catch client.reinit() exceptions in async producer (dpkp)
* Producer.stop() now blocks until async thread completes (dpkp PR 485)
* Catch errors during load_metadata_for_topics in async producer (bschopman PR 467)
* Add compression-level support for codecs that support it (trbs PR 454)
* Fix translation of Java murmur2 code, fix byte encoding for Python 3 (chrischamberlin PR 439)
* Only call stop() on not-stopped producer objects (docker-hub PR 435)
* Allow null payload for deletion feature (scrapinghub PR 409)

Clients
* Use non-blocking io for broker aware requests (ecanzonieri PR 473)
* Use debug logging level for metadata request (ecanzonieri PR 415)
* Catch KafkaUnavailableError in _send_broker_aware_request (mutability PR 436)
* Lower logging level on replica not available and commit (ecanzonieri PR 415)

Documentation
* Update docs and links wrt maintainer change (mumrah -> dpkp)

Internals
* Add py35 to tox testing
* Update travis config to use container infrastructure
* Add 0.8.2.2 and 0.9.0.0 resources for integration tests; update default official releases
* new pylint disables for pylint 1.5.1 (zackdever PR 481)
* Fix python3 / python2 comments re queue/Queue (dpkp)
* Add Murmur2Partitioner to kafka __all__ imports (dpkp Issue 471)
* Include LICENSE in PyPI sdist (koobs PR 441)

Consumers
* Refactor SimpleConsumer internal fetch handling (dpkp PR 399)
* Handle exceptions in SimpleConsumer commit() and reset_partition_offset() (dpkp PR 404)
* Improve FailedPayloadsError handling in KafkaConsumer (dpkp PR 398)
* KafkaConsumer: avoid raising KeyError in task_done (dpkp PR 389)
* MultiProcessConsumer -- support configured partitions list (dpkp PR 380)
* Fix SimpleConsumer leadership change handling (dpkp PR 393)
* Fix SimpleConsumer connection error handling (reAsOn2010 PR 392)
* Improve Consumer handling of 'falsy' partition values (wting PR 342)
* Fix _offsets call error in KafkaConsumer (hellais PR 376)
* Fix str/bytes bug in KafkaConsumer (dpkp PR 365)
* Register atexit handlers for consumer and producer thread/multiprocess cleanup (dpkp PR 360)
* Always fetch commit offsets in base consumer unless group is None (dpkp PR 356)
* Stop consumer threads on delete (dpkp PR 357)
* Deprecate metadata_broker_list in favor of bootstrap_servers in KafkaConsumer (dpkp PR 340)
* Support pass-through parameters in multiprocess consumer (scrapinghub PR 336)
* Enable offset commit on SimpleConsumer.seek (ecanzonieri PR 350)
* Improve multiprocess consumer partition distribution (scrapinghub PR 335)
* Ignore messages with offset less than requested (wkiser PR 328)
* Handle OffsetOutOfRange in SimpleConsumer (ecanzonieri PR 296)

Producers
* Add Murmur2Partitioner (dpkp PR 378)
* Log error types in SimpleProducer and SimpleConsumer (dpkp PR 405)
* SimpleProducer support configuration of fail_on_error (dpkp PR 396)
* Deprecate KeyedProducer.send() (dpkp PR 379)
* Further improvements to async producer code (dpkp PR 388)
* Add more configuration parameters for async producer (dpkp)
* Deprecate SimpleProducer batch_send=True in favor of async (dpkp)
* Improve async producer error handling and retry logic (vshlapakov PR 331)
* Support message keys in async producer (vshlapakov PR 329)
* Use threading instead of multiprocessing for Async Producer (vshlapakov PR 330)
* Stop threads on __del__ (chmduquesne PR 324)
* Fix leadership failover handling in KeyedProducer (dpkp PR 314)

KafkaClient
* Add .topics property for list of known topics (dpkp)
* Fix request / response order guarantee bug in KafkaClient (dpkp PR 403)
* Improve KafkaClient handling of connection failures in _get_conn (dpkp)
* Client clears local metadata cache before updating from server (dpkp PR 367)
* KafkaClient should return a response or error for each request - enable better retry handling (dpkp PR 366)
* Improve str/bytes conversion in KafkaClient and KafkaConsumer (dpkp PR 332)
* Always return sorted partition ids in client.get_partition_ids_for_topic() (dpkp PR 315)

Documentation
* Cleanup Usage Documentation
* Improve KafkaConsumer documentation (dpkp PR 341)
* Update consumer documentation (sontek PR 317)
* Add doc configuration for tox (sontek PR 316)
* Switch to .rst doc format (sontek PR 321)
* Fixup google groups link in README (sontek PR 320)
* Automate documentation at kafka-python.readthedocs.org

Internals
* Switch integration testing from 0.8.2.0 to 0.8.2.1 (dpkp PR 402)
* Fix most flaky tests, improve debug logging, improve fixture handling (dpkp)
* General style cleanups (dpkp PR 394)
* Raise error on duplicate topic-partition payloads in protocol grouping (dpkp)
* Use module-level loggers instead of simply 'kafka' (dpkp)
* Remove pkg_resources check for __version__ at runtime (dpkp PR 387)
* Make external API consistently support python3 strings for topic (kecaps PR 361)
* Fix correlation id overflow (dpkp PR 355)
* Cleanup kafka/common structs (dpkp PR 338)
* Use context managers in gzip_encode / gzip_decode (dpkp PR 337)
* Save failed request as FailedPayloadsError attribute (jobevers PR 302)
* Remove unused kafka.queue (mumrah)