１．迁移topic到新增的node上
假如现在一个kafka集群运行三个broker，broker.id依次为101,102,103,后来由于业务数据突然暴增，需要新增三个broker,broker.id依次为104,105,106.目的是要把chatmessage迁移到新增node上。脚本(json格式)如下所示：
kafka-reassign-partitions.sh --zookeeper 192.168.1.10: --topics-to-move-json-file migration-chatmessage-topic.json --broker-list "104,105,106" --generate
migration-chatmessage-topic.json文件内容如下：
{
"topics":
[
{
"topic": "chatmessage"
}
],
"version":
}生成分配partitions的json脚本：
{
"version":,
"partitions":
[
{
"topic":"chatmessage",
"partition":,"replicas":[]
},
{
"topic":"chatmessage",
"partition":,
"replicas":[]
},
{
"topic":"chatmessage",
"partition":,
"replicas":[]
},
{
"topic":"chatmessage",
"partition":,
"replicas":[]
},
{
"topic":"chatmessage",
"partition":,
"replicas":[]
},
{
"topic":"chatmessage",
"partition":,
"replicas":[]
},
{
"topic":"chatmessage",
"partition":,
"replicas":[]
},
{
"topic":"chatmessage",
"partition":,
"replicas":[]
},
{
"topic":"chatmessage",
"partition":,
"replicas":[]
},
{
"topic":"chatmessage",
"partition":,
"replicas":[]
},
{
"topic":"chatmessage",
"partition":,
"replicas":[]
},
{
"topic":"chatmessage",
"partition":,
"replicas":[]
}
]
}
}重新分配parttions的json脚本如下：migration-topic-chatmessage-topic.json
{"version":,
"partitions":
[
{"topic":"cluster-switch-topic","partition":,"replicas":[]},
{"topic":"cluster-switch-topic","partition":,"replicas":[]},
{"topic":"cluster-switch-topic","partition":,"replicas":[]},
{"topic":"cluster-switch-topic","partition":,"replicas":[]},
{"topic":"cluster-switch-topic","partition":,"replicas":[]},
{"topic":"cluster-switch-topic","partition":,"replicas":[]},
{"topic":"cluster-switch-topic","partition":,"replicas":[]},
{"topic":"cluster-switch-topic","partition":,"replicas":[]},
{"topic":"cluster-switch-topic","partition":,"replicas":[]},
{"topic":"cluster-switch-topic","partition":,"replicas":[]},
{"topic":"cluster-switch-topic","partition":,"replicas":[]},
{"topic":"cluster-switch-topic","partition":,"replicas":[]}
]
}执行一下脚本
./kafka-reassign-partitions.sh --zookeeper 192.168.1.10: --reassignment-json-file migration-topic-chatmessage-topic.json --execute
topic修改(replicats-factor)副本个数
假如初始时chatmessage为一个副本，为了提高可用性，需要改为2副本模式。脚本replicas-chatmessage-topic.json文件内容如下:
{
"partitions":
[
{
"topic": "chatmessage",
"partition": ,
"replicas": [,,]
},
{
"topic": "chatmessage",
"partition": ,
"replicas": [,,]
},
.......
"version":
}编辑好json文件后执行一下命令：
./kafka-reassign-partitions.sh --zookeeper 192.168.1.10: --reassignment-json-file replicas-chatmessage-topic.json --execute
3.topic的分区扩容用法
先扩容分区数量，脚本如下:
./kafka-topics.sh --zookeeper 192.168.1.10: --alter --partitions --topic chatmessage
把topic为chatmessage的分区数量扩展到１５个。
设置topic分区副本：
{
"partitions":
[
{
"topic": "chatmessage",
"partition": ,
"replicas": [,]
},
{
"topic": "chatmessage",
"partition": ,
"replicas": [,]
},
{
"topic": "chatmessage",
"partition": ,
"replicas": [,]
}
],
"version":
}编辑json文件，执行一下脚本：
./bin/kafka-reassign-partitions.sh --zookeeper 192.168.１.10: --reassignment-json-file partitions-extension-chatmessage-topic.json --execute