librdkafka v1.8.0

librdkafka v1.8.0 is a security release:

• Upgrade bundled zlib version from 1.2.8 to 1.2.11 in the librdkafka.redist NuGet package. The updated zlib version fixes CVEs: CVE-2016-9840, CVE-2016-9841, CVE-2016-9842, CVE-2016-9843 See https://github.com/edenhill/librdkafka/issues/2934 for more information.
• librdkafka now uses vcpkg for up-to-date Windows dependencies in the librdkafka.redist NuGet package: OpenSSL 1.1.1l, zlib 1.2.11, zstd 1.5.0.
• The upstream dependency (OpenSSL, zstd, zlib) source archive checksums are now verified when building with ./configure --install-deps. These builds are used by the librdkafka builds bundled with confluent-kafka-go, confluent-kafka-python and confluent-kafka-dotnet.

Enhancements

• Producer flush() now overrides the linger.ms setting for the duration of the flush() call, effectively triggering immediate transmission of queued messages. (#3489)

Fixes

General fixes

• Correctly detect presence of zlib via compilation check. (Chris Novakovic)
• ERR__ALL_BROKERS_DOWN is no longer emitted when the coordinator connection goes down, only when all standard named brokers have been tried. This fixes the issue with ERR__ALL_BROKERS_DOWN being triggered on consumer_close(). It is also now only emitted if the connection was fully up (past handshake), and not just connected.
• rd_kafka_query_watermark_offsets(), rd_kafka_offsets_for_times(), consumer_lag metric, and auto.offset.reset now honour isolation.level and will return the Last Stable Offset (LSO) when isolation.level is set to read_committed (default), rather than the uncommitted high-watermark when it is set to read_uncommitted. (#3423)
• SASL GSSAPI is now usable when sasl.kerberos.min.time.before.relogin is set to 0 - which disables ticket refreshes (by @mpekalski, #3431).
• Rename internal crc32c() symbol to rd_crc32c() to avoid conflict with other static libraries (#3421).
• txidle and rxidle in the statistics object was emitted as 18446744073709551615 when no idle was known. -1 is now emitted instead. (#3519)

Consumer fixes

• Automatically retry offset commits on ERR_REQUEST_TIMED_OUT, ERR_COORDINATOR_NOT_AVAILABLE, and ERR_NOT_COORDINATOR (#3398). Offset commits will be retried twice.
• Timed auto commits did not work when only using assign() and not subscribe(). This regression was introduced in v1.7.0.
• If the topics matching the current subscription changed (or the application updated the subscription) while there was an outstanding JoinGroup or SyncGroup request, an additional request would sometimes be sent before handling the response of the first. This in turn lead to internal state issues that could cause a crash or malbehaviour. The consumer will now wait for any outstanding JoinGroup or SyncGroup responses before re-joining the group.
• auto.offset.reset could previously be triggered by temporary errors, such as disconnects and timeouts (after the two retries are exhausted). This is now fixed so that the auto offset reset policy is only triggered for permanent errors.
• The error that triggers auto.offset.reset is now logged to help the application owner identify the reason of the reset.
• If a rebalance takes longer than a consumer's session.timeout.ms, the consumer will remain in the group as long as it receives heartbeat responses from the broker.

Admin fixes

• DeleteRecords() could crash if one of the underlying requests (for a given partition leader) failed at the transport level (e.g., timeout). (#3476).

Checksums

Release asset checksums:

• v1.8.0.zip SHA256 4b173f759ea5fdbc849fdad00d3a836b973f76cbd3aa8333290f0398fd07a1c4
• v1.8.0.tar.gz SHA256 93b12f554fa1c8393ce49ab52812a5f63e264d9af6a50fd6e6c318c481838b7f