本文环境如下:
操作系统:Mac Os
JDK版本:1.7.0_77 64位
Kafka版本:2.10
下载、解压Kafka安装包
Kafka官网地址: http://kafka.apache.org/
Kafka目录介绍
- /bin 操作kafka的可执行脚本,还包含windows下脚本
- /config 配置文件所在目录
- /libs 依赖库目录
- /logs 日志数据目录,目录kafka把server端日志分为5种类型,分为:server,request,state,log-cleaner,controller
启动单机模式
- 修改配置文件 进入kafka安装工程根目录编辑config/server.properties
kafka最为重要三个配置依次为:broker.id、log.dir、zookeeper.connect,kafka server端config/server.properties参数说明和解释如下:
cd /opt/kafka_2.11-0.9.0.1/config
vi server.properties
修改配置文件中的以下内容:
broker.id=0 //为依次增长的:0、1、2、3、4,集群中唯一id
log.dirs=/opt/kafka_2.11-0.9.0.1/logs //日志地址
zookeeper.connect=master:2181,slave1:2181,slave2:2181 //zookeeperServers列表,各节点以逗号分开
启动程序
先要确保zookeeper已启动,然后在Kafka目录执行
nohup bin/kafka-server-start.sh config/server.properties&
如果无报错则说明启动成功。nohup &是实现在后台启动。
- 检测2181与9092端口
netstat -tunlp|egrep "(2181|9092)" tcp 0 0 :::2181 :::* LISTEN 19787/java tcp 0 0 :::9092 :::* LISTEN 28094/java
说明: Kafka的进程ID为28094,占用端口为9092
QuorumPeerMain为对应的zookeeper实例,进程ID为19787,在2181端口监听
简单测试
打开2个终端,分别在Kafka目录执行以下命令
- 启动producer
bin/kafka-console-producer.sh --broker-list localhost:9092 --topic test
- 启动consumer
bin/kafka-console-consumer.sh --zookeeper localhost:2181 --topic test --from-beginning
在producer的命令行输入任意字符,观察consumer是否能正确接收。
- 注意:
producer,指定的Socket(localhost:9092),说明生产者的消息要发往kafka,也即是broker
consumer, 指定的Socket(localhost:2181),说明消费者的消息来自zookeeper(协调转发)
上面的只是一个单个的broker,下面我们来实验一个多broker的集群。
搭建一个多个broker的伪集群(配置三个kafka)
刚才只是启动了单个broker,现在启动有3个broker组成的集群,这些broker节点也都是在本机上。
(1)为每一个broker提供配置文件
我们先看看config/server0.properties配置信息:
broker.id=0
listeners=PLAINTEXT://:9092
port=9092
host.name=192.168.1.181
num.network.threads=4
num.io.threads=8
socket.send.buffer.bytes=102400
socket.receive.buffer.bytes=102400
socket.request.max.bytes=104857600
log.dirs=/tmp/kafka-logs
num.partitions=5
num.recovery.threads.per.data.dir=1
log.retention.hours=168
log.segment.bytes=1073741824
log.retention.check.interval.ms=300000
log.cleaner.enable=false
zookeeper.connect=192.168.1.181:2181
zookeeper.connection.timeout.ms=6000
queued.max.requests =500
log.cleanup.policy = delete
- 说明:
broker.id为集群中唯一的标注一个节点,因为在同一个机器上,所以必须指定不同的端口和日志文件,避免数据被覆盖。
在上面单个broker的实验中,为什么kafka的端口为9092,这里可以看得很清楚。
kafka cluster怎么同zookeeper交互的,配置信息中也有体现。
那么下面,我们仿照上面的配置文件,提供2个broker的配置文件:
- server1.properties:
broker.id=1 listeners=PLAINTEXT://:9093 port=9093 host.name=192.168.1.181 num.network.threads=4 num.io.threads=8 socket.send.buffer.bytes=102400 socket.receive.buffer.bytes=102400 socket.request.max.bytes=104857600 log.dirs=/tmp/kafka-logs1 num.partitions=5 num.recovery.threads.per.data.dir=1 log.retention.hours=168 log.segment.bytes=1073741824 log.retention.check.interval.ms=300000 log.cleaner.enable=false zookeeper.connect=192.168.1.181:2181 zookeeper.connection.timeout.ms=6000 queued.max.requests =500 log.cleanup.policy = delete
- server2.properties:
broker.id=2 listeners=PLAINTEXT://:9094 port=9094 host.name=192.168.1.181 num.network.threads=4 num.io.threads=8 socket.send.buffer.bytes=102400 socket.receive.buffer.bytes=102400 socket.request.max.bytes=104857600 log.dirs=/tmp/kafka-logs2 num.partitions=5 num.recovery.threads.per.data.dir=1 log.retention.hours=168 log.segment.bytes=1073741824 log.retention.check.interval.ms=300000 log.cleaner.enable=false zookeeper.connect=192.168.1.181:2181 zookeeper.connection.timeout.ms=6000 queued.max.requests =500 log.cleanup.policy = delete
启动所有的broker
命令如下:
bin/kafka-server-start.sh config/server0.properties & #启动broker0
bin/kafka-server-start.sh config/server1.properties & #启动broker1
bin/kafka-server-start.sh config/server2.properties & #启动broker2
查看2181、9092、9093、9094端口
netstat -tunlp|egrep "(2181|9092|9093|9094)"
tcp 0 0 :::9093 :::* LISTEN 29725/java
tcp 0 0 :::2181 :::* LISTEN 19787/java
tcp 0 0 :::9094 :::* LISTEN 29800/java
tcp 0 0 :::9092 :::* LISTEN 29572/java
一个zookeeper在2181端口上监听,3个kafka cluster(broker)分别在端口9092,9093,9094监听。
创建topic
bin/kafka-topics.sh --create --topic topic_1 --partitions 1 --replication-factor 3 \--zookeeper localhost:2181
bin/kafka-topics.sh --create --topic topic_2 --partitions 1 --replication-factor 3 \--zookeeper localhost:2181
bin/kafka-topics.sh --create --topic topic_3 --partitions 1 --replication-factor 3 \--zookeeper localhost:2181
查看topic创建情况:
bin/kafka-topics.sh --list --zookeeper localhost:2181
test
topic_1
topic_2
topic_3
[root@atman081 kafka_2.10-0.9.0.0]# bin/kafka-topics.sh --describe --zookeeper localhost:2181
Topic:test PartitionCount:1 ReplicationFactor:1 Configs:
Topic: test Partition: 0 Leader: 0 Replicas: 0 Isr: 0
Topic:topic_1 PartitionCount:1 ReplicationFactor:3 Configs:
Topic: topic_1 Partition: 0 Leader: 2 Replicas: 2,1,0 Isr: 2,1,0
Topic:topic_2 PartitionCount:1 ReplicationFactor:3 Configs:
Topic: topic_2 Partition: 0 Leader: 1 Replicas: 1,2,0 Isr: 1,2,0
Topic:topic_3 PartitionCount:1 ReplicationFactor:3 Configs:
Topic: topic_3 Partition: 0 Leader: 0 Replicas: 0,2,1 Isr: 0,2,1
上面的有些东西,也许还不太清楚,暂放,继续试验。需要注意的是topic_1的Leader=2
模拟客户端发送,接受消息
- 发送消息
bin/kafka-console-producer.sh --topic topic_1 --broker-list 127.0.0.1:9092,127.0.0.1:9093,127.0.0.1:9094
接收消息
bin/kafka-console-consumer.sh --topic topic_1 --zookeeper 127.0.0.1:2181 --from-beginning
需要注意,此时producer将topic发布到了3个broker中,现在就有点分布式的概念了。
kill some broker
kill broker(id=0)
首先,我们根据前面的配置,得到broker(id=0)应该在9092监听,这样就能确定它的PID了。
broker0没kill之前topic在kafka cluster中的情况
bin/kafka-topics.sh --describe --zookeeper localhost:2181
Topic:test PartitionCount:1 ReplicationFactor:1 Configs:
Topic: test Partition: 0 Leader: 0 Replicas: 0 Isr: 0
Topic:topic_1 PartitionCount:1 ReplicationFactor:3 Configs:
Topic: topic_1 Partition: 0 Leader: 2 Replicas: 2,1,0 Isr: 2,1,0
Topic:topic_2 PartitionCount:1 ReplicationFactor:3 Configs:
Topic: topic_2 Partition: 0 Leader: 1 Replicas: 1,2,0 Isr: 1,2,0
Topic:topic_3 PartitionCount:1 ReplicationFactor:3 Configs:
Topic: topic_3 Partition: 0 Leader: 2 Replicas: 0,2,1 Isr: 2,1,0
kill之后,再观察,做下对比。很明显,主要变化在于Isr,以后再分析
bin/kafka-topics.sh --describe --zookeeper localhost:2181
Topic:test PartitionCount:1 ReplicationFactor:1 Configs:
Topic: test Partition: 0 Leader: -1 Replicas: 0 Isr:
Topic:topic_1 PartitionCount:1 ReplicationFactor:3 Configs:
Topic: topic_1 Partition: 0 Leader: 2 Replicas: 2,1,0 Isr: 2,1
Topic:topic_2 PartitionCount:1 ReplicationFactor:3 Configs:
Topic: topic_2 Partition: 0 Leader: 1 Replicas: 1,2,0 Isr: 1,2
Topic:topic_3 PartitionCount:1 ReplicationFactor:3 Configs:
Topic: topic_3 Partition: 0 Leader: 2 Replicas: 0,2,1 Isr: 2,1
测试下,发送消息,接受消息,是否收到影响。
发送消息
bin/kafka-console-producer.sh --topic topic_1 --broker-list 127.0.0.1:9092,127.0.0.1:9093,127.0.0.1:9094
接收消息
bin/kafka-console-consumer.sh –topic topic_1 –zookeeper 127.0.0.1:2181 –from-beginning 可见,kafka的分布式机制,容错能力还是挺好的~
Kafka介绍
- kafka有什么?
-
producer 消息的生成者,即发布消息
-
consumer 消息的消费者,即订阅消息
-
broker Kafka以集群的方式运行,可以由一个或多个服务组成,服务即broker
-
zookeeper 协调转发