History

José Armando García Sancio 7b6d4fbc57 KAFKA-17333; ResignedState should not notify of leader change (#16900 ) When a voter fails as leader (LeaderState) the quorum-state still states that it is the leader of the epoch. When the voter starts it never starts as leader and instead starts as resigned (ResignedState) if it was previously a leader. This causes the KRaft client to immediately notify the state machine (e.g QuorumController) that it is leader or active. This is incorrect for two reasons. One, the controller cannot be notified of leadership until it has reached the LEO. If the controller is notified before that it will generate and append records that are not based on the latest state. Two, it is not practical to notify of local leadership when it is resigned since any write operation (prepareAppend and schedulePreparedAppend) will fail with NotLeaderException while KRaft is in the resigned state. Reviewers: Colin P. McCabe <cmccabe@apache.org>, David Arthur <mumrah@gmail.com>		2024-08-20 16:24:13 -07:00
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bin	MINOR: Self-managed -> KRaft (Kafka Raft) (#10414 )	2021-03-29 15:39:10 -07:00
config	KAFKA-13073: Fix MockLog snapshot implementation (#11032 )	2021-07-13 17:06:18 -07:00
src	KAFKA-17333; ResignedState should not notify of leader change (#16900 )	2024-08-20 16:24:13 -07:00
.gitignore	KAFKA-13429: ignore bin on new modules (#11415 )	2021-11-10 14:36:24 -06:00
README.md	MINOR: remove kraft readme link (#13691 )	2023-05-10 16:40:20 +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

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
bin/test-kraft-server-start.sh --config config/kraft-quorum-2.properties
bin/test-kraft-server-start.sh --config config/kraft-quorum-3.properties

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.