Kafka入门教程(二)

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ywb201314 2022-08-01 12:17:58 博主文章分类：Kafka

Kafka集群环境安装

Kafka集群规划

主机名	IP	安装软件
Kafka1	192.168.1.221	Jdk、Zookeeper、Kafka
Kafka2	192.168.1.222	Jdk、Zookeeper、Kafka
Kafka3	192.168.1.223	Jdk、Zookeeper、Kafka

1. 配置ssh免密码登录：

产生密钥，执行命令：ssh-keygen -t rsa,按4回车，密钥文件位于\~/.ssh文件
在192.168.1.221上生产一对钥匙，将公钥拷贝到其他节点，包括自己，执行命令：
ssh-copy-id 192.168.1.221
ssh-copy-id 192.168.1.222
ssh-copy-id 192.168.1.223
在192.168.1.222上生产一对钥匙，将公钥拷贝到其他节点，包括自己，执行命令：
ssh-copy-id 192.168.1.221
ssh-copy-id 192.168.1.222
ssh-copy-id 192.168.1.223
在192.168.1.223上生产一对钥匙，将公钥拷贝到其他节点，包括自己，执行命令：
ssh-copy-id 192.168.1.221
ssh-copy-id 192.168.1.222
ssh-copy-id 192.168.1.223

在所有的服务器上设置环境变量：

export JAVA_HOME=/usr/local/software/jdk1.8.0_66
export CLASSPATH=.:$JAVA_HOME</span>/lib/dt.<span class="hljs-symbol">jar:</span><span class="hljs-variable">$JAVA_HOME/lib/tools.jar
export KAFKA_HOME=/usr/local/software/kafka_2.11-1.0.0
export ZOOKEEPER_HOME=/usr/local/software/zookeeper-3.4.11
export PATH=.:$JAVA_HOME</span>/<span class="hljs-symbol">bin:</span><span class="hljs-variable">$KAFKA_HOME/bin:$ZOOKEEPER_HOME</span>/<span class="hljs-symbol">bin:</span><span class="hljs-variable">$PATH

tl stop firewalld.service

systemctl disable firewalld.service

安装Kafka

分别在[Kafka1、Kafka2、Kafka3]服务器下载：

tar -zxvf kafka_2.11-1.0.0.tgz

2. 修改配置文件：
Kafka1服务器配置文件
broker.id=0
listeners=PLAINTEXT://:9092
log.dir= /usr/local/software/kafka_2.11-1.0.0/kafka-logs
Kafka2服务器配置文件
broker.id=1
listeners=PLAINTEXT://:9092
log.dir= /usr/local/software/kafka_2.11-1.0.0/kafka-logs
Kafka3服务器配置文件
broker.id=2
listeners=PLAINTEXT://:9092
log.dir= /usr/local/software/kafka_2.11-1.0.0/kafka-logs

分别启动[Kafka1、Kafka2、Kafka3]服务器的kafka服务

启动命令：./bin/kafka-server-start.sh -daemon config/server.properties
查看启动日志：tail -100f logs/server.log
查看启动端口：lsof -i:9092

创建主题Topic

创建主题topic

执行命令：bin/kafka-topics.sh - -create - -zookeeper 192.168.1.221:2181
- -replication-factor 2 - -partitions 2 - -topic test

查看主题topic描述

执行命令：bin/kafka-topics.sh –list –zookeeper 192.168.1.223:2181

1. 查看创建的所有主题
执行命令：bin/kafka-topics.sh –list –zookeeper 192.168.1.223:2181

生产者生产消息

执行命令：bin/kafka-console-producer.sh –broker-list 192.168.1.221:9092 –topic test

消费者消费消息

执行命令：bin/kafka-console-consumer.sh –bootstrap-server 192.168.1.223:9092 –topic test –from-beginning

JAVA客户端

新建一个maven项目，项目名称：kafka-demo：

代码结构如下：

1. Maven的pom.xml文件：

<project xmlns="http://maven.apache.org/POM/4.0.0" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
  xsi:schemaLocation="http://maven.apache.org/POM/4.0.0 http://maven.apache.org/xsd/maven-4.0.0.xsd">
  <modelVersion>4.0.0</modelVersion>

  <groupId>com.kafka</groupId>
  <artifactId>kafka-demo</artifactId>
  <version>1.0-SNAPSHOT</version>
  <build>
    <plugins>
      <plugin>
        <groupId>org.apache.maven.plugins</groupId>
        <artifactId>maven-compiler-plugin</artifactId>
        <configuration>
          <source>1.8</source>
          <target>1.8</target>
        </configuration>
      </plugin>
    </plugins>
  </build>
  <packaging>jar</packaging>

  <name>kafka-demo</name>
  <url>http://maven.apache.org</url>

  <properties>
    <project.build.sourceEncoding>UTF-8</project.build.sourceEncoding>
  </properties>

  <dependencies>
    <dependency>
      <groupId>junit</groupId>
      <artifactId>junit</artifactId>
      <version>4.12</version>
      <scope>test</scope>
    </dependency>
    <!-- https://mvnrepository.com/artifact/org.apache.kafka/kafka-clients -->
    <dependency>
      <groupId>org.apache.kafka</groupId>
      <artifactId>kafka-clients</artifactId>
      <version>1.0.0</version>
    </dependency>
  </dependencies>
</project>

生产者代码实现：

package com.kafka;
import org.apache.kafka.clients.producer.KafkaProducer;
import org.apache.kafka.clients.producer.Producer;
import org.apache.kafka.clients.producer.ProducerRecord;

import java.util.Properties;
/**
 * 生产者代码
 */
public class DemoProducer{
    public static void main( String[] args ){
        Properties props = new Properties();
        props.put("bootstrap.servers", "192.168.1.221:9092,192.168.1.222:9092,192.168.1.223:9092");
        props.put("acks", "all");
        props.put("retries", 0);
        props.put("batch.size", 16384);
        props.put("linger.ms", 1);
        props.put("buffer.memory", 33554432);
        props.put("key.serializer", "org.apache.kafka.common.serialization.StringSerializer");
        props.put("value.serializer", "org.apache.kafka.common.serialization.StringSerializer");

        Producer<String, String> producer = new KafkaProducer<>(props);
        for(int i = 0; i < 10; i++) {
            producer.send(new ProducerRecord<>("test", Integer.toString(i), "message_value=====>" + i));
        }
        producer.close();
    }
}

消费者代码实现：

package com.kafka;
import org.apache.kafka.clients.consumer.ConsumerRecord;
import org.apache.kafka.clients.consumer.ConsumerRecords;
import org.apache.kafka.clients.consumer.KafkaConsumer;

import java.util.Arrays;
import java.util.Properties;
/**
 * 消费者代码
 */
public class DemoConsumer {
    public static void main(String[] args) {
        Properties props = new Properties();
        props.put("bootstrap.servers", "192.168.1.221:9092,192.168.1.222:9092,192.168.1.223:9092");
        props.put("group.id", "test");
        props.put("enable.auto.commit", "true");
        props.put("auto.commit.interval.ms", "1000");
        props.put("session.timeout.ms", "30000");
        props.put("key.deserializer", "org.apache.kafka.common.serialization.StringDeserializer");
        props.put("value.deserializer", "org.apache.kafka.common.serialization.StringDeserializer");
        KafkaConsumer<String, String> consumer = new KafkaConsumer<>(props);
        consumer.subscribe(Arrays.asList("test"));
        while(true) {
            ConsumerRecords<String, String> records = consumer.poll(100);
            for(ConsumerRecord<String, String> record : records) {
                System.out.printf("offset = %d, key = %s, value = %s\n", record.offset(), record.key(), record.value());
            }
        }
    }
}

消息结果：
message_value=====>1
message_value=====>5
message_value=====>7
message_value=====>8
message_value=====>4
message_value=====>6
message_value=====>0
message_value=====>2
message_value=====>3
message_value=====>9