Kafka 代理从集群中移除且重新分配失败后降低主题复制因子答案

【问题标题】：Decrease topic replication factor after Kafka brokers removed from cluster and failed reassignmentsKafka 代理从集群中移除且重新分配失败后降低主题复制因子
【发布时间】：2021-03-18 21:32:55
【问题描述】：

主题复制因子已增加到 45，而集群中可用的 Kafka 代理数量为 40。

这是由于重复的分区重新分配被停止而导致的。

kafka-topics --topic top --zookeeper zoo_url --describe

表演

Partition: 0 Leader: 20464 Replicas: 20464,20765,1882,20870,873,898,20752,16789,17181,20743,20854,20762,894,20459,20851,21070,20757,20766,20763,890,21173,20852,895,21314,20767,883,20467,16787,21071,20750,887,20760,7067,876,20764,891,20768,4880,20769,16788,20756,886,21172,1582,871,16827 Isr: 20464,20765,1882,20870,873,898,20752,16789,17181,20743,20762,894,20459,21070,20757,20766,20763,890,21173,895,21314,20767,883,20467,16787,20750,887,20760,7067,876,20764,891,20768,4880,20769,16788,20756,886,21172,871,16827 ...

一些副本不是集群的一部分。

跑步：

kafka-reassign-partitions --zookeeper zoo_url --topics-to-move-json-file assign.json --generate --broker-list ...

失败并出现以下错误

Partitions reassignment failed due to replication factor: 45 larger than available brokers: 21
kafka.admin.AdminOperationException: replication factor: 45 larger than available brokers: 21
    at kafka.admin.AdminUtils$.assignReplicasToBrokers(AdminUtils.scala:117)
    at kafka.admin.ReassignPartitionsCommand$$anonfun$generateAssignment$1.apply(ReassignPartitionsCommand.scala:110)
    at kafka.admin.ReassignPartitionsCommand$$anonfun$generateAssignment$1.apply(ReassignPartitionsCommand.scala:108)
    at scala.collection.immutable.Map$Map1.foreach(Map.scala:116)
    at kafka.admin.ReassignPartitionsCommand$.generateAssignment(ReassignPartitionsCommand.scala:108)
    at kafka.admin.ReassignPartitionsCommand$.generateAssignment(ReassignPartitionsCommand.scala:91)
    at kafka.admin.ReassignPartitionsCommand$.main(ReassignPartitionsCommand.scala:50)
    at kafka.admin.ReassignPartitionsCommand.main(ReassignPartitionsCommand.scala)

--broker-list 参数输入是在线经纪人的 id。

如何强制降低主题复制因子？

唯一有效的解决方案是通过运行降低一个分区的复制因子

kafka-reassign-partitions --zookeeper zoo_url --reassignment-json-file /tmp/assign.json --execute

当/tmp/assign.json 如下图时

{ "partitions": [ { "partition": 0, "replicas": [20743,20762,894,20459,20757,895,20467,20760], "topic": "topic" } ], "version": 1 }

然后重新运行分区赋值（生成赋值并执行）

Kafka 0.9.0.1 被部署为 Cloudera 的一部分。

【问题讨论】：

所以，我要问...为什么需要超过 3-5 个副本？

标签： apache-kafka apache-zookeeper cloudera kafka-topic kafka-partition

【解决方案1】：

您可以在{ "partitions": [ 列表中添加多个分区，但使用kafka-reassign-partitions 是处理此问题的唯一内置方法。可能有外部工具可以设法以编程方式生成该 JSON，但在尝试查找当前分配中的未知代理 ID 时它们也可能出错

【讨论】：