History

kevin-wu24 184b891871 KAFKA-16524; Metrics for KIP-853 (#18304 ) This change implement some of the metrics enumerated in KIP-853. The KafkaRaftMetrics object now exposes number-of-voters, number-of-observers and uncommitted-voter-change. The number-of-observers and uncommitted-voter-change metrics are only present on the active controller or leader, since it does not make sense for other replicas to report these metrics. In order to make these two metrics thread-safe, KafkaRaftMetrics needs to be passed into LeaderState, and therefore QuorumState. This introduces a circularity since the KafkaRaftMetrics constructor takes in QuorumState. To break the circularity for now, the logic using QuorumState will be moved to the KafkaRaftMetrics#initialize method. The BrokerServerMetrics object now exposes ignored-static-voters. The ControllerServerMetrics object now exposes IgnoredStaticVoters. To implement both metrics for "ignored static voters", this PR introduces the ExternalKRaftMetrics interface, which allows for higher layer metrics objects to be accessible within the raft module. Reviewers: José Armando García Sancio <jsancio@apache.org>		2025-01-30 18:35:01 -05:00
..
bin	KAFKA-18388 test-kraft-server-start.sh should use log4j2.yaml (#18370 )	2025-01-07 04:20:06 +08:00
config	KAFKA-18388 test-kraft-server-start.sh should use log4j2.yaml (#18370 )	2025-01-07 04:20:06 +08:00
src	KAFKA-16524; Metrics for KIP-853 (#18304 )	2025-01-30 18:35:01 -05:00
.gitignore	KAFKA-13429: ignore bin on new modules (#11415 )	2021-11-10 14:36:24 -06:00
README.md	KAFKA-17728 Add missing config `replica-directory-id` to raft README (#17518 )	2024-10-17 11:32:27 +08:00

README.md

KRaft (Kafka Raft)

KRaft (Kafka Raft) is a protocol based on the Raft Consensus Protocol tailored for Apache Kafka.

This is used by Apache Kafka in the KRaft (Kafka Raft Metadata) mode. We also have a standalone test server which can be used for performance testing. We describe the details to set this up below.

Run Single Quorum

bin/test-kraft-server-start.sh --config config/kraft.properties --replica-directory-id b8tRS7h4TJ2Vt43Dp85v2A

Run Multi Node Quorum

Create 3 separate KRaft quorum properties as the following:

cat << EOF >> config/kraft-quorum-1.properties

node.id=1
listeners=PLAINTEXT://localhost:9092
controller.listener.names=PLAINTEXT
controller.quorum.voters=1@localhost:9092,2@localhost:9093,3@localhost:9094
log.dirs=/tmp/kraft-logs-1
EOF

cat << EOF >> config/kraft-quorum-2.properties

node.id=2
listeners=PLAINTEXT://localhost:9093
controller.listener.names=PLAINTEXT
controller.quorum.voters=1@localhost:9092,2@localhost:9093,3@localhost:9094
log.dirs=/tmp/kraft-logs-2
EOF

cat << EOF >> config/kraft-quorum-3.properties

node.id=3
listeners=PLAINTEXT://localhost:9094
controller.listener.names=PLAINTEXT
controller.quorum.voters=1@localhost:9092,2@localhost:9093,3@localhost:9094
log.dirs=/tmp/kraft-logs-3
EOF

Open up 3 separate terminals, and run individual commands:

bin/test-kraft-server-start.sh --config config/kraft-quorum-1.properties --replica-directory-id b8tRS7h4TJ2Vt43Dp85v2A
bin/test-kraft-server-start.sh --config config/kraft-quorum-2.properties --replica-directory-id Nkij_D9XRiYKNb41SiJo7Q
bin/test-kraft-server-start.sh --config config/kraft-quorum-3.properties --replica-directory-id 4-e97nI7eHPYKfEDtW8rtQ

Once a leader is elected, it will begin writing to an internal __raft_performance_test topic with a steady workload of random data. You can control the workload using the --throughput and --record-size arguments passed to test-kraft-server-start.sh.