kafka 修改副本数

本文完全参考官网：
官网链接：https://kafka.apache.org/21/documentation.html#basic_ops_increase_replication_factor
例如，以下示例将主题foo的分区0的复制因子从1增加到3。在增加复制因子之前，该分区的唯一副本存在于broker.id为5的节点上，我们将在broker.id为6和7的节点上各增加一个副本。
第一步先创建一个Json文件，格式如下：

>cat increase-replication-factor.json

{"version":1,
"partitions":[{"topic":"foo","partition":0,"replicas":[5,6,7]}]}

然后，将json文件与--execute选项一起使用以开始重新分配过程：

> bin/kafka-reassign-partitions.sh --zookeeper localhost:2181 \
--reassignment-json-file increase-replication-factor.json --execute

运行结果：

Current partition replica assignment
 
{"version":1,
"partitions":[{"topic":"foo","partition":0,"replicas":[5]}]}
 
Save this to use as the --reassignment-json-file option during rollback
Successfully started reassignment of partitions
{"version":1,
"partitions":[{"topic":"foo","partition":0,"replicas":[5,6,7]}]}

验证结果：

> bin/kafka-topics.sh --zookeeper localhost:2181 --topic foo --describe
Topic:foo   PartitionCount:1    ReplicationFactor:3 Configs:
  Topic: foo    Partition: 0    Leader: 5   Replicas: 5,6,7 Isr: 5,6,7

多分区修改副本数示例：

{"version":1,
"partitions":[{"topic":"event","partition":0,"replicas":[530,531]},
          {"topic":"event","partition":1,"replicas":[531,528]},
          {"topic":"event","partition":2,"replicas":[528,529]}
         ]
}