Recently, we found a regression that could have been detected by static
analysis, since a local variable wasn't being passed to a method during
a refactoring, and was left unused. It was fixed in
[7a749b5](7a749b589f),
but almost slipped into 4.0. Unused variables are typically detected by
IDEs, but this is insufficient to prevent these kinds of bugs. This
change enables unused local variable detection in checkstyle for Kafka.
A few notes on the usage:
- There are two situations in which people actually want to have a local
variable but not use it. First, there are `for (Type ignored:
collection)` loops which have to loop `collection.length` number of
times, but that do not use `ignored` in the loop body. These are
typically still easier to read than a classical `for` loop. Second, some
IDEs detect it if a return value of a function such as `File.delete` is
not being used. In this case, people sometimes store the result in an
unused local variable to make ignoring the return value explicit and to
avoid the squiggly lines.
- In Java 22, unsued local variables can be omitted by using a single
underscore `_`. This is supported by checkstyle. In pre-22 versions,
IntelliJ allows such variables to be named `ignored` to suppress the
unused local variable warning. This pattern is often (but not
consistently) used in the Kafka codebase. This is, however, not
supported by checkstyle.
Since we cannot switch to Java 22, yet, and we want to use automated
detection using checkstyle, we have to resort to prefixing the unused
local variables with `@SuppressWarnings("UnusedLocalVariable")`. We have
to apply this in 11 cases across the Kafka codebase. While not being
pretty, I'd argue it's worth it to prevent bugs like the one fixed in
[7a749b5](7a749b589f).
Reviewers: Andrew Schofield <aschofield@confluent.io>, David Arthur
<mumrah@gmail.com>, Matthias J. Sax <matthias@confluent.io>, Bruno
Cadonna <cadonna@apache.org>, Kirk True <ktrue@confluent.io>
* Add `DynamicThreadPool.java` to the server module.
* Remove the old DynamicThreadPool object in the `DynamicBrokerConfig.scala`.
Reviewers: TengYao Chi <kitingiao@gmail.com>, Chia-Ping Tsai <chia7712@gmail.com>
The kafka controllers need to set kraft.version in their
ApiVersionsResponse messages according to the current kraft.version
reported by the Raft layer. Instead, currently they always set it to 0.
Also remove FeatureControlManager.latestFinalizedFeatures. It is not
needed and it does a lot of copying.
Reviewers: Jun Rao <junrao@gmail.com>, Chia-Ping Tsai <chia7712@gmail.com>
When producers send future timestamps, time retention based log segments
may get blocked from removal for an extended period of time. Log
cleaning should should warn in the logs when this scenario occurs.
Reviewers: Viktor Somogyi-Vass <viktorsomogyi@gmail.com>
Migrate AdminClientRebootstrapTest to the new test infra and remove the
old Scala test.
Reviewers: TengYao Chi <kitingiao@gmail.com>, David Arthur <mumrah@gmail.com>
User testing of the `KafkaShareConsumer` interface has revealed some
areas which confuse people. One of these is that way that it decides
whether you want to use implicit or explicit acknowledgement of records
by observing which calls the application issues. We are taking the
opportunity to refine the interface before it is finalised.
This PR introduces an experimental configuration called
`internal.share.acknowledgement.mode` which can be used to make the
application declare which kind of acknowledgement it wishes to use. We
plan to try out the configuration, assess whether it has helped, and
then create a proper consumer configuration that makes this area better.
That would require a lot of change in the tests, which explains why this
initial PR only has a small number of tests.
Reviewers: David Arthur <mumrah@gmail.com>
1. Updated JavaDoc to reflect that CreateTopicPolicy and AlterConfigPolicy run on the controller in KRaft mode.
2. Modified Behavioral Change Reference in the HTML docs to include this change.
3. add warning message to KafkaConfig if the config of broker node has policy configs
Reviewers: TengYao Chi <kitingiao@gmail.com>, Ken Huang <s7133700@gmail.com>, Chia-Ping Tsai <chia7712@gmail.com>
The PR corrects the way the locks are released on exception. As
`partitionsAcquired` can be a reference to `topicPartitionData`, hence
the locks should released prior clearing `partitionsAcquired`.
Reviewers: Abhinav Dixit <adixit@confluent.io>, Andrew Schofield <aschofield@confluent.io>
When regular expressions are resolved, they do not update the group by
topics data structure. Hence, topic changes (e.g. deletion) do not
trigger a rebalance of the group.
Reviewers: Lucas Brutschy <lbrutschy@confluent.io>
This PR reduces `maxInterval` for `resendExponentialBackoff` in
`BrokerLifecycleManager` class from `broker.session.timeout.ms` to half
of its value. Setting `maxInterval` to `broker.session.timeout.ms`
caused brokers to be fenced if a resend attempt occurred near the
timeout threshold, leading to unnecessary broker fencing.
Reviewers: Colin P. McCabe <cmccabe@apache.org>
Implements auto-topic creation when handling the streams group
heartbeat.
Inside KafkaApis, the handler for streamsGroupHeartbeat uses the result
of the streams group heartbeat inside the group coordinator to attempt
to create all missing internal topics using AutoTopicCreationManager.
CREATE TOPIC ACLs are checked. The unit tests class
AutoTopicCreationManagerTest is brought back (it was recently deleted
during a ZK removal PR), but testing only the kraft-related
functionality.
Reviewers: Bruno Cadonna <bruno@confluent.io>
### Committer Checklist (excluded from commit message)
- [ ] Verify design and implementation
- [ ] Verify test coverage and CI build status
- [ ] Verify documentation (including upgrade notes)
Remove kafka.cluster.Broker and BrokerEndPointNotAvailableException as they were used by zk path.
Reviewers: TengYao Chi <kitingiao@gmail.com>, Ken Huang <s7133700@gmail.com>, Chia-Ping Tsai <chia7712@gmail.com>
The PR implements the SharePartitionMetrics as defined in KIP-1103, with
one change. The metric `FetchLockRatio` is defined as `Meter` in KIP but
is implemented as `HIstogram`. There was a discussion about same on
KIP-1103 discussion where we thought that `FetchLockRatio` is
pre-aggregated but while implemeting the rate from `Meter` can go above
100 as `Meter` defines rate per time period. Hence it makes more sense
to implement metric `FetchLockRatio` as `Histogram`.
Reviewers: Andrew Schofield <aschofield@confluent.io>
This patch filters out the topic describe unauthorized topics from the
ConsumerGroupHeartbeat and ConsumerGroupDescribe response.
In ConsumerGroupHeartbeat,
- if the request has `subscribedTopicNames` set, we directly check the
authz in `KafkaApis` and return a topic auth failure in the response if
any of the topics is denied.
- Otherwise, we check the authz only if a regex refresh is triggered and
we do it based on the acl of the consumer that triggered the refresh. If
any of the topic is denied, we filter it out from the resolved
subscription.
In ConsumerGroupDescribe, we check the authz of the coordinator
response. If any of the topic in the group is denied, we remove the
described info and add a topic auth failure to the described group.
(similar to the group auth failure)
Reviewers: David Jacot <djacot@confluent.io>, Lianet Magrans
<lmagrans@confluent.io>, Rajini Sivaram <rajinisivaram@googlemail.com>,
Chia-Ping Tsai <chia7712@gmail.com>, TaiJuWu <tjwu1217@gmail.com>,
TengYao Chi <kitingiao@gmail.com>
This change implements the basic RPC handling StreamsGroupHeartbeat and
StreamsGroupDescribe. This includes:
- Adding an option to enable streams groups on the broker
- Passing describe and heartbeats to the right shard of the group
coordinator
- The handler inside the GroupMetadatManager for StreamsGroupDescribe is
fairly trivial, and is included directly in this PR.
- The handler for StreamsGroupHeartbeat is complex and not included in
this PR yet. Instead, a UnsupportedOperationException is thrown.
However, the interface is already defined: The result of a
streamsGroupHeartbeat is a response, together with a list of internal
topics to be created.
The heartbeat implementation inside the `GroupMetadataManager`, which
actually implements the assignment / reconciliation logic, will come in
a follow-up PR. Also, automatic creation of internal topics will be
created in a follow-up PR.
Reviewers: Bill Bejeck <bill@confluent.io>
### About
The current `SimpleAssignor` in AK assigned all subscribed topic
partitions to all the share group members. This does not match the
description given in
[KIP-932](https://cwiki.apache.org/confluence/pages/viewpage.action?pageId=255070434#KIP932:QueuesforKafka-TheSimpleAssignor).
Here are the rules as mentioned in the KIP by which the assignment
should happen. We have changed the step 3 implementation here due to the
reasons
[described](https://github.com/apache/kafka/pull/18864#issuecomment-2659266502)
-
1. The assignor hashes the member IDs of the members and maps the
partitions assigned to the members based on the hash. This gives
approximately even balance.
2. If any partitions were not assigned any members by (1) and do not
have members already assigned in the current assignment, members are
assigned round-robin until each partition has at least one member
assigned to it.
3. We combine the current and new assignment. (Original rule - If any
partitions were assigned members by (1) and also have members in the
current assignment assigned by (2), the members assigned by (2) are
removed.)
### Tests
The added code has been verified with unit tests and the already present
integration tests.
Reviewers: Andrew Schofield <aschofield@confluent.io>, Apoorv Mittal <apoorvmittal10@gmail.com>, TaiJuWu <tjwu1217@gmail.com>
For the KRaft implementation there is a race between the network thread,
which read bytes in the log segments, and the KRaft driver thread, which
truncates the log and appends records to the log. This race can cause
the network thread to send corrupted records or inconsistent records.
The corrupted records case is handle by catching and logging the
CorruptRecordException. The inconsistent records case is handle by only
appending record batches who's partition leader epoch is less than or
equal to the fetching replica's epoch and the epoch didn't change
between the request and response.
For the ISR implementation there is also a race between the network
thread and the replica fetcher thread, which truncates the log and
appends records to the log. This race can cause the network thread send
corrupted records or inconsistent records. The replica fetcher thread
already handles the corrupted record case. The inconsistent records case
is handle by only appending record batches who's partition leader epoch
is less than or equal to the leader epoch in the FETCH request.
Reviewers: Jun Rao <junrao@apache.org>, Alyssa Huang <ahuang@confluent.io>, Chia-Ping Tsai <chia7712@apache.org>
The PR handles fetch for `compacted` topics. The fix was required only
when complete batch disappears from the topic log, and same batch is
marked re-available in Share Partition state cache. Subsequent log reads
will not result the disappeared batch in read response hence respective
batch will be left as available in the state cache.
The PR checks for the first fetched/read batch base offset and if it's
greater than the position from where the read occurred (fetch offset)
then if there exists any `available` batches in the state cache then
they will be archived.
Reviewers: Andrew Schofield <aschofield@confluent.io>, Abhinav Dixit <adixit@confluent.io>
When a cluster is configured with a dynamic controller quorum, KRaft replica's endpoint are computed using the advertised.listeners property and not the quorum.controller.voters property. This change in the configuration makes it difficult to keeping all previous node configurations compatible with the new endpoint discovery functionality.
The least intrusive solution is to rely on Kafka's reverse hostname lookup when the hostname is not specified. The effective advertised controller listener now remove '0.0.0.0' hostname if the endpoint came from the listener configuration and not the advertised.listener configuration.
Reviewers: José Armando García Sancio <jsancio@apache.org>, Alyssa Huang <ahuang@confluent.io>
The PR handles slicing of fetched records based on acquire response for
share fetch. There could be additional bytes fetched from log but
acquired offsets can be a subset, typically with `max fetch records`
configuration. Rather sending additional bytes of fetched data to client
we should slice the file and wire only needed batches.
Note: If the acquired offsets are within a batch then we need to send
the entire batch within the file record. Hence rather checking for
individual batches, PR finds the first and last acquired offset, and
trims the file for all batches between (inclusive) these two offsets.
Reviewers: Christo Lolov <lolovc@amazon.com>, Andrew Schofield <aschofield@confluent.io>, Jun Rao <junrao@gmail.com>
The PR does following:
1. Adds `fetchOffset` to `acquire` API in SharePartition.
2. Adds a ShareFetchPartitionData class efficiently handle the
propagation of fetchOffset information.
3. Updates SharePartitionTests to make common code so such improvements
does not require all tests changes for future PRs.
Reviewers: Andrew Schofield <aschofield@confluent.io>
PR implements the final set of ShareGroupMetrics,
RequestTopicPartitionsFetchRatio and TopicPartitionsAcquireTimeMs, as
defined in KIP-1103:
https://cwiki.apache.org/confluence/display/KAFKA/KIP-1103%3A+Additional+metrics+for+cooperative+consumption
Note: Metric `RequestTopicPartitionsFetchRatio` is calculated as
percentage as Histogram API doesn't record double.
Reviewers: Andrew Schofield <aschofield@confluent.io>, Abhinav Dixit <adixit@confluent.io>
- ELR is enabled (ELRV_1) by default if the cluster is created with its bootstrap metadata version >= IBP_4_1_IV0.
- ELRV_1 can be manually enabled iff the metadata version is >= IBP_4_0_IV1.
Reviewers: Ismael Juma <ismael@juma.me.uk>, Colin P. McCabe <cmccabe@apache.org>, David Jacot <djacot@confluent.io>
3 tests which were marked flaky in ShareConsumerTest do not have any
failure on trunk since the test was converted to use `ClusterTestExtensions`.
Reviewers: Sushant Mahajan <smahajan@confluent.io>, Apoorv Mittal <apoorvmittal10@gmail.com>, Andrew Schofield <aschofield@confluent.io>
The current Docker Hub documentation for Kafka is based on the use of static voters. Since Kafka 4.0 utilizes dynamic voters, users following the doc of docker hub may encounter unexpected behavior. Due to the limited time available for the 4.0.0 release, a simple and quick solution is to revert to using static voters within the Docker image. This can be achieved by adding a configuration file with static voter definitions to the kafka/docker folder, keeping it separate from the main kafka/config directory. This approach allows us to encourage the use of dynamic voters in typical deployments while maintaining compatibility within the Docker image.
Reviewers: Vedarth Sharma <142404391+VedarthConfluent@users.noreply.github.com>, Chia-Ping Tsai <chia7712@gmail.com>
fix the following behavior changes.
1) in log4j 1, users can't change the logger by parent if the logger is declared by properties explicitly. For example, `org.apache.kafka.controller` has level explicitly in the properties. Hence, we can't use "org.apache.kafka=INFO" to change the level of `org.apache.kafka.controller` to INFO. By contrast, log4j2 allows us to change all child loggers by the parent logger.
2) in log4j2, we can change the level of root to impact all loggers' level. By contrast, log4j 1 can't.
Reviewers: Chia-Ping Tsai <chia7712@gmail.com>
Cleanup code to avoid rawtype, and add suppressions where necessary.
Change the build to fail on rawtype warning.
Reviewers: Apoorv Mittal <apoorvmittal10@gmail.com>, Andrew Schofield <aschofield@confluent.io>
Lucas Brutschy
Azhar Ahmed
Ken Huang
PoAn Yang
ClarkChen
Colin Patrick McCabe
Dániel Urbán
Andrew Schofield
co63oc
Xuan-Zhang Gong
Lan Ding
Kuan-Po Tseng
Logan Zhu
Apoorv Mittal
David Jacot
Nick Guo
Mahsa Seifikar
TengYao Chi
Dongnuo Lyu
Abhinav Dixit
José Armando García Sancio
xijiu
TaiJuWu
mingdaoy
Ismael Juma
Sushant Mahajan
Calvin Liu
Shivsundar R
Matthias J. Sax