How to find if all the partitions have been moved to the "preferred replica" after running the tool? When the replica becomes "in-sync" with the leader, the tool can be run again to move the leader. This is to ensure that there is no dataloss. The controller will fail to move the leadership to the preferred replica if it is not in the ISR. How to use the tool?įAQ What happens if the preferred replica is not in the ISR? The controller moves the leader for a partition to the preferred replica asynchronously. Note that the tool only updates the zookeeper path and exits. If the preferred replica is not already the leader and it is present in the isr, the controller issues a request to the broker that owns the preferred replica to become the leader for the partition. For each topic partition, the controller gets the preferred replica (the first replica in the assigned replicas list). When a data change update is triggered, the controller reads the list of topic partitions from zookeeper. The controller listens to the path above. The tool updates the zookeeper path "/admin/preferred_replica_election" with the list of topic partitions whose leader needs to be moved to the preferred replica. A summary of the steps that the tool does is shown below -ġ. This tool helps to restore the leadership balance between the brokers in the cluster.
However, over time the leadership load could get imbalanced due to broker shutdowns (caused by controlled shutdown, crashes, machine failures etc). This guarantees that the leadership load across the brokers in a cluster are evenly balanced. In an ideal scenario, the leader for a given partition should be the "preferred replica". When topic/partitions are created, Kafka ensures that the "preferred replica" for the partitions across topics are equally distributed amongst the brokers in a cluster. The first replica in this list is the "preferred replica". The list of replicas for a partition is called the "assigned replicas".
With replication, each partition can have multiple replicas. Preferred Replica Leader Election Tool What does the tool do?
0 kommentar(er)
