Kafka - Zookeeper/Kafka集群的部署

下载kafka，自带 zookeeper。

搭建Zookeeper集群

zookeeper 集群使用 Raft 选举模式，故至少要三个节点（生产中应部署在三个不同的服务器实例上，这里用于演示就不那么做了）。

# 复制三分节点配置
cp config/zookeeper.properties config/zookeeper.2181.properties
cp config/zookeeper.properties config/zookeeper.2182.properties
cp config/zookeeper.properties config/zookeeper.2183.properties

修改配置
config/zookeeper.2181.properties

# the directory where the snapshot is stored.
dataDir=/tmp/zookeeper/2181
# the port at which the clients will connect
clientPort=2181
# disable the per-ip limit on the number of connections since this is a non-production config
maxClientCnxns=0
tickTime=2000
initLimit=10
syncLimit=5
server.1=localhost:12888:13888
server.2=localhost:22888:23888
server.3=localhost:32888:33888

config/zookeeper.2182.properties 修改clientPort=2182 dataDir=/tmp/zookeeper/2182 其他一致
config/zookeeper.2183.properties 修改clientPort=2183 dataDir=/tmp/zookeeper/2183 其他一致

主要是修改服务端口clientPort和数据目录dataDir，其他参数表征如下：
tickTime=2000为zk的基本时间单元，毫秒
initLimit=10Leader-Follower初始通信时限（tickTime*10)
syncLimit=5Leader-Follower同步通信时限（tickTime*5)
server.实例集群标识=实例地址:数据通信端口:选举通信端口

为实例添加集群标识

echo 1 >> /tmp/zookeeper/2181/myid
echo 2 >> /tmp/zookeeper/2182/myid
echo 3 >> /tmp/zookeeper/2183/myid

启动集群服务

bin/zookeeper-server-start.sh config/zookeeper.2181.properties
bin/zookeeper-server-start.sh config/zookeeper.2182.properties
bin/zookeeper-server-start.sh config/zookeeper.2183.properties

搭建Kafka集群

Kafka集群节点>=2时便可对外提供高可用服务

cp config/server.properties config/server.9092.properties
cp config/server.properties config/server.9093.properties

修改节点标识、服务端口、数据目录和zk集群节点列表
vi config/server.9092.properties

broker.id=1
...
listeners=PLAINTEXT://:9092
...
log.dirs=/tmp/kafka-logs/1
...
zookeeper.connect=localhost:2181,localhost:2182,localhost:2183

vi config/server.9093.properties

broker.id=2
...
listeners=PLAINTEXT://:9093
...
log.dirs=/tmp/kafka-logs/2
...
zookeeper.connect=localhost:2181,localhost:2182,localhost:2183

启动集群

bin/kafka-server-start.sh config/server.9092.properties
bin/kafka-server-start.sh config/server.9093.properties

Topic管理

创建topic

bin/kafka-topics.sh --create \
--zookeeper localhost:2181,localhost:2182,localhost:2183 \
--replication-factor 2 \
--partition 4 \
--topic topic_1

--replication-factor 2：副本集数量，不能大于 broker 节点数量，多了也没用，1个节点放>=2个副本挂了都完蛋。
--partition 4：分区数

查看topic列表

bin/kafka-topics.sh \
--zookeeper localhost:2181,localhost:2182,localhost:2183 --list
topic_1
topic_2

查看Topic详情

可以描述Topic分区数/副本数/副本Leader/副本ISR等信息：

bin/kafka-topics.sh \
--zookeeper localhost:2181,localhost:2182,localhost:2183 \
--describe --topic topic_1
Topic:topic_1    PartitionCount:4    ReplicationFactor:2    Configs:
    Topic: topic_1    Partition: 0    Leader: 2    Replicas: 2,1    Isr: 2,1
    Topic: topic_1    Partition: 1    Leader: 1    Replicas: 1,2    Isr: 1,2
    Topic: topic_1    Partition: 2    Leader: 2    Replicas: 2,1    Isr: 2,1
    Topic: topic_1    Partition: 3    Leader: 1    Replicas: 1,2    Isr: 1,2

删除Topic

注意，只是删除Topic在zk的元数据，日志数据仍需手动删除。

bin/kafka-topics.sh \
--zookeeper localhost:2181,localhost:2182,localhost:2183 \
--delete --topic topic_2

#Topic topic_2 is marked for deletion.
#Note: This will have no impact if delete.topic.enable is not set to true.

#再查看topic列表
bin/kafka-topics.sh \
--zookeeper localhost:2181,localhost:2182,localhost:2183 --list

#topic_1
#topic_2 - marked for deletion

生产者

bin/kafka-console-producer.sh \
--broker-list localhost:9092,localhost:9093 \
--topic topic_1
# 进入 cli 输入消息回车发送
# hello kafka [enter]
# send message [enter]

消费者

新模式，offset存储在borker
--new-consumer Use new consumer. This is the default.
--bootstrap-server <server to connectto> REQUIRED (unless old consumer is used): The server to connect to.
老消费模式，offset存储在zk
--zookeeper <urls> REQUIRED (only when using old consumer): The connection string for the zookeeper connection in the form host:port. Multiple URLS can be given to allow fail-over.

创建消费者

bin/kafka-console-consumer.sh \
--new-consumer \
--bootstrap-server localhost:9092,localhost:9093 \
--from-beginning \
--topic topic_1

可以尝试创建多个不同消费组的消费者（这里的sh脚本创建的都是不同消费组的），订阅同一个topic来实现发布订阅模式。

查看消费组/消费者

bin/kafka-consumer-groups.sh \
--new-consumer \
--bootstrap-server localhost:9092,localhost:9093 \
--list
#这里有两个消费组的消费者
console-consumer-47566
console-consumer-50875

查看消费详情

可以查看到消费的订阅的 topic，负责的 partition，消费进度 offset, 积压的消息LAG。

bin/kafka-consumer-groups.sh \
--new-consumer \
--bootstrap-server localhost:9092,localhost:9093 \
--group console-consumer-47566 \
--describe

GROUP                          TOPIC                          PARTITION  CURRENT-OFFSET  LOG-END-OFFSET  LAG             OWNER
console-consumer-47566         topic_1                        0          2               2               0               consumer-1_/127.0.0.1
console-consumer-47566         topic_1                        1          3               3               0               consumer-1_/127.0.0.1
console-consumer-47566         topic_1                        2          2               3               1               consumer-1_/127.0.0.1
console-consumer-47566         topic_1                        3          0               3               3               consumer-1_/127.0.0.1