Kafka实践
提前准备:
- 安装Java
- 安装zookeeper
一、kafka集群安装
分别在h1、h2、h3三台机器上下载解压kafka安装包,然后修改配置文件
1.h1上,vi /home/vagrant/kafka_2.11-1.1.0/config/server.properties
broker.id=1
listeners=PLAINTEXT://10.0.34.112:9092
zookeeper.connect=h1:2181,h2:2181,h3:2181
2.h2上,vi /home/vagrant/kafka_2.11-1.1.0/config/server.properties
broker.id=2
listeners=PLAINTEXT://10.0.34.111:9092
zookeeper.connect=h1:2181,h2:2181,h3:2181
3.h3上,vi /home/vagrant/kafka_2.11-1.1.0/config/server.properties
broker.id=3
listeners=PLAINTEXT://10.0.34.110:9092
zookeeper.connect=h1:2181,h2:2181,h3:2181
二、启动集群,操作kafka
相关命令:
开启zookeeper:
zkServer.sh start
关闭zookeeper:
zkServer.sh stop
启动kafka
./bin/kafka-server-start.sh config/server.properties
创建主题,指定分区数和副本数
./bin/kafka-topics.sh --create --zookeeper h1:2181,h2:2181,h3:2181 --replication-factor 2 --partitions 3 --topic first-topic
显示主题列表
./bin/kafka-topics.sh --list --zookeeper localhost:2181
查看指定主题
./bin/kafka-topics.sh --describe --zookeeper localhost:2181 --topic first-topic
修改主题分区数
./bin/kafka-topics.sh —zookeeper localhost:2181 --alter --topic first-topic --parti-tions 2
删除主题
./bin/kafka-topics.sh --zookeeper localhost:2181 --delete --topic first-topic
启动生产者
./bin/kafka-console-producer.sh --broker-list h1:9092,h2:9092,h3:9092 --topic first-topic
启动消费者
./bin/kafka-console-consumer.sh --bootstrap-server h1:9092,h2:9092,h3:9092 --from-beginning -topic first-topic
停止kakfa
./bin/kafka-server-stop.sh config/server.properties
启动kafka之后,启动一个生产者和消费者:演示发送消息和接收消息
连接zookeeper,查看topic
三、使用Java API操作kafka
1.创建、删除topic
package testKafka;
import java.util.Properties;
import org.apache.kafka.common.security.JaasUtils;
import kafka.admin.AdminUtils;
import kafka.admin.RackAwareMode;
import kafka.utils.ZkUtils;
public class CreateTopic {
public static void main(String[] args) {
ZkUtils zkUtils = ZkUtils.apply("10.0.34.112:2181,10.0.34.111:2181,10.0.34.110:2181", 30000,30000,JaasUtils.isZkSecurityEnabled());
AdminUtils.createTopic(zkUtils, "second-topic", 1, 1, new Properties(), RackAwareMode.Enforced$.MODULE$);
// AdminUtils.deleteTopic(zkUtils, "second-topic");
zkUtils.close();
}
}
执行代码,查看控制台,多一个topic
2.创建生产者,发送消息
package testKafka;
import java.util.Properties;
import org.apache.kafka.clients.producer.KafkaProducer;
import org.apache.kafka.clients.producer.Producer;
import org.apache.kafka.clients.producer.ProducerRecord;
public class ProducerDemo {
public static void main(String[] args) {
Properties properties = new Properties();
properties.put("bootstrap.servers", "10.0.34.112:9092,10.0.34.111:9092,10.0.34.110:9092");
properties.put("acks", "all");
properties.put("retries", 10);
properties.put("batch.size", 16384);
properties.put("linger.ms", 1);
properties.put("buffer.memory", 33554432);
properties.put("key.serializer", "org.apache.kafka.common.serialization.StringSerializer");
properties.put("value.serializer", "org.apache.kafka.common.serialization.StringSerializer");
Producer producer = null;
try {
producer = new KafkaProducer(properties);
for(int i =0;i<10;i++) {
String msg = "Message" + i;
producer.send(new ProducerRecord("first-topic", msg));
System.out.println("Sent: "+msg);
}
} catch (Exception e) {
e.printStackTrace();
} finally {
producer.close();
}
}
}
查看控制台
3.创建消费者,接收数据
package testKafka;
import java.util.Arrays;
import java.util.Properties;
import org.apache.kafka.clients.consumer.ConsumerRecord;
import org.apache.kafka.clients.consumer.ConsumerRecords;
import org.apache.kafka.clients.consumer.KafkaConsumer;
public class ConsumerDemo {
public static void main(String[] args) {
Properties props = new Properties();
props.put("bootstrap.servers", "10.0.34.112:9092,10.0.34.111:9092,10.0.34.110:9092");
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 consumer = new KafkaConsumer<>(props);
consumer.subscribe(Arrays.asList("first-topic"));
while (true) {
ConsumerRecords records = consumer.poll(100);
for (ConsumerRecord record : records)
System.out.printf("offset = %d, key = %s, value = %s\n", record.offset(), record.key(), record.value());
}
}
}
截图