1.环境搭建
下载地址:https://kafka.apache.org/downloads
解压缩即可完成安装
2.服务启动
//我演示使用的windows版,命令如下
//进入命令执行目录
cd D:\queue\kafka_2.13-2.8.1\bin\windows
//启动zookeeper
zookeeper-server-start.bat ..\..\config\zookeeper.properties
//启动kafka
kafka-server-start.bat ..\..\config\server.properties
我使用的是2.8.1这个版本,启动时可以直接使用kafka包自带的zookeeper进行启动,如果启动完zookeeper后,启动kafka发生错误,可能需要下载一个和kafka相应版本的zookeeper。
3.名词说明
- Broker。负责接收和处理客户端发送过来的请求,以及对消息进行持久化。虽然多个 Broker 进程能够运行在同一台机器上,但更常见的做法是将不同的 Broker 分散运行在不同的机器上
- 主题:Topic。主题是承载消息的逻辑容器,在实际使用中多用来区分具体的业务。
- 分区:Partition。一个有序不变的消息序列。每个主题下可以有多个分区。
- 消息:这里的消息就是指 Kafka 处理的主要对象。
- 消息位移:Offset。表示分区中每条消息的位置信息,是一个单调递增且不变的值。
- 副本:Replica。Kafka 中同一条消息能够被拷贝到多个地方以提供数据冗余,这些地方就是所谓的副本。副本还分为领导者副本和追随者副本,各自有不同的角色划分。每个分区可配置多个副本实现高可用。一个分区的N个副本一定在N个不同的Broker上。
- Leader:每个分区多个副本的“主”副本,生产者发送数据的对象,以及消费者消费数据的对象,都是 Leader。
- Follower:每个分区多个副本的“从”副本,实时从 Leader 中同步数据,保持和 Leader 数据的同步。Leader 发生故障时,某个 Follower 还会成为新的 Leader。
- 生产者:Producer。向主题发布新消息的应用程序。
- 消费者:Consumer。从主题订阅新消息的应用程序。
- 消费者位移:Consumer Offset。表示消费者消费进度,每个消费者都有自己的消费者位移。offset保存在broker端的内部topic中,不是在clients中保存
- 消费者组:Consumer Group。多个消费者实例共同组成的一个组,同时消费多个分区以实现高吞吐。
- 重平衡:Rebalance。消费者组内某个消费者实例挂掉后,其他消费者实例自动重新分配订阅主题分区的过程。Rebalance 是 Kafka 消费者端实现高可用的重要手段。
4.执行步骤
(1) Producer 生产消息,发送到Broker中
(2) Leader状态的Broker接收消息,写入到相应topic中。在一个分区内,这些消息被索引并连同时间戳存储在一起
(3) Leader状态的Broker接收完毕以后,传给Follow状态的Broker作为副本备份
(4) Consumer 消费者的进程可以从分区订阅,并消费消息
5.示例
(1)引入依赖
<dependency>
<groupId>org.springframework.kafka</groupId>
<artifactId>spring-kafka</artifactId>
</dependency>
这边默认使用2.8.10版本
(2)配置
kafka:
bootstrap-servers: 127.0.0.1:9092
consumer:
group-id: kafak_order
(2)服务层
package com.example.demo.kafka.impl;
import cn.hutool.core.util.StrUtil;
import com.example.demo.kafka.KafkaMessageService;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.kafka.core.KafkaTemplate;
import org.springframework.kafka.support.SendResult;
import org.springframework.stereotype.Service;
import org.springframework.util.concurrent.ListenableFuture;
import org.springframework.util.concurrent.ListenableFutureCallback;
/**
* @author linaibo
* @version 1.0
* Create by 2022/12/25 19:59
*/
@Service
public class KafkaMessageServiceImpl implements KafkaMessageService {
@Autowired
private KafkaTemplate<String,String> kafkaTemplate;
@Override
public void sendMessage(String msg) {
System.out.println("Kafka消息开始发送");
ListenableFuture<SendResult<String,String>> future = kafkaTemplate.send("order",msg);
future.addCallback(new ListenableFutureCallback<SendResult<String, String>>() {
@Override
public void onFailure(Throwable ex) {
System.out.println("发送消息失败" + ex.getMessage());
}
@Override
public void onSuccess(SendResult<String, String> result) {
//主题
String topic = result.getRecordMetadata().topic();
//分区
int partition = result.getRecordMetadata().partition();
//offset
long offset = result.getRecordMetadata().offset();
System.out.println(StrUtil.format("消息发送成功,topic={},partition={},offset={}",topic,partition,offset));
}
});
}}
将消息发送到特定的主题中,并对结果进行判断,成功的场合可以获取消息的信息,失败的场合可以获取失败的原因。
(3)监听器
package com.example.demo.kafka.listener;
import org.apache.kafka.clients.consumer.ConsumerRecord;
import org.springframework.kafka.annotation.KafkaListener;
import org.springframework.stereotype.Component;
/**
* @author linaibo
* @version 1.0
* Create by 2022/12/25 20:02
*/
@Component
public class KafkaMessageListener {
@KafkaListener(topics = {"order"})
public void onMessage(ConsumerRecord<String,String> record){
System.out.println("接收到发送的kafka消息" + record.value());
System.out.println("接收到发送的kafka消息" + record);
}
}
运行结果
Kafka消息开始发送
2022-12-31 13:10:14.366 INFO 78104 --- [nio-8888-exec-1] o.a.k.clients.producer.ProducerConfig : ProducerConfig values:
acks = -1
batch.size = 16384
bootstrap.servers = [127.0.0.1:9092]
buffer.memory = 33554432
client.dns.lookup = use_all_dns_ips
client.id = producer-1
compression.type = none
connections.max.idle.ms = 540000
delivery.timeout.ms = 120000
enable.idempotence = true
interceptor.classes = []
key.serializer = class org.apache.kafka.common.serialization.StringSerializer
linger.ms = 0
max.block.ms = 60000
max.in.flight.requests.per.connection = 5
max.request.size = 1048576
metadata.max.age.ms = 300000
metadata.max.idle.ms = 300000
metric.reporters = []
metrics.num.samples = 2
metrics.recording.level = INFO
metrics.sample.window.ms = 30000
partitioner.class = class org.apache.kafka.clients.producer.internals.DefaultPartitioner
receive.buffer.bytes = 32768
reconnect.backoff.max.ms = 1000
reconnect.backoff.ms = 50
request.timeout.ms = 30000
retries = 2147483647
retry.backoff.ms = 100
sasl.client.callback.handler.class = null
sasl.jaas.config = null
sasl.kerberos.kinit.cmd = /usr/bin/kinit
sasl.kerberos.min.time.before.relogin = 60000
sasl.kerberos.service.name = null
sasl.kerberos.ticket.renew.jitter = 0.05
sasl.kerberos.ticket.renew.window.factor = 0.8
sasl.login.callback.handler.class = null
sasl.login.class = null
sasl.login.connect.timeout.ms = null
sasl.login.read.timeout.ms = null
sasl.login.refresh.buffer.seconds = 300
sasl.login.refresh.min.period.seconds = 60
sasl.login.refresh.window.factor = 0.8
sasl.login.refresh.window.jitter = 0.05
sasl.login.retry.backoff.max.ms = 10000
sasl.login.retry.backoff.ms = 100
sasl.mechanism = GSSAPI
sasl.oauthbearer.clock.skew.seconds = 30
sasl.oauthbearer.expected.audience = null
sasl.oauthbearer.expected.issuer = null
sasl.oauthbearer.jwks.endpoint.refresh.ms = 3600000
sasl.oauthbearer.jwks.endpoint.retry.backoff.max.ms = 10000
sasl.oauthbearer.jwks.endpoint.retry.backoff.ms = 100
sasl.oauthbearer.jwks.endpoint.url = null
sasl.oauthbearer.scope.claim.name = scope
sasl.oauthbearer.sub.claim.name = sub
sasl.oauthbearer.token.endpoint.url = null
security.protocol = PLAINTEXT
security.providers = null
send.buffer.bytes = 131072
socket.connection.setup.timeout.max.ms = 30000
socket.connection.setup.timeout.ms = 10000
ssl.cipher.suites = null
ssl.enabled.protocols = [TLSv1.2]
ssl.endpoint.identification.algorithm = https
ssl.engine.factory.class = null
ssl.key.password = null
ssl.keymanager.algorithm = SunX509
ssl.keystore.certificate.chain = null
ssl.keystore.key = null
ssl.keystore.location = null
ssl.keystore.password = null
ssl.keystore.type = JKS
ssl.protocol = TLSv1.2
ssl.provider = null
ssl.secure.random.implementation = null
ssl.trustmanager.algorithm = PKIX
ssl.truststore.certificates = null
ssl.truststore.location = null
ssl.truststore.password = null
ssl.truststore.type = JKS
transaction.timeout.ms = 60000
transactional.id = null
value.serializer = class org.apache.kafka.common.serialization.StringSerializer
2022-12-31 13:10:14.376 INFO 78104 --- [nio-8888-exec-1] o.a.k.clients.producer.KafkaProducer : [Producer clientId=producer-1] Instantiated an idempotent producer.
2022-12-31 13:10:14.390 INFO 78104 --- [nio-8888-exec-1] o.a.kafka.common.utils.AppInfoParser : Kafka version: 3.1.2
2022-12-31 13:10:14.390 INFO 78104 --- [nio-8888-exec-1] o.a.kafka.common.utils.AppInfoParser : Kafka commitId: f8c67dc3ae0a3265
2022-12-31 13:10:14.390 INFO 78104 --- [nio-8888-exec-1] o.a.kafka.common.utils.AppInfoParser : Kafka startTimeMs: 1672463414390
2022-12-31 13:10:14.397 INFO 78104 --- [ad | producer-1] org.apache.kafka.clients.Metadata : [Producer clientId=producer-1] Resetting the last seen epoch of partition order-0 to 0 since the associated topicId changed from null to Cc4Zxy54SbC-ylUTv7wCKQ
2022-12-31 13:10:14.397 INFO 78104 --- [ad | producer-1] org.apache.kafka.clients.Metadata : [Producer clientId=producer-1] Cluster ID: 9kfe9DyPRpeGhkcflXFSTA
2022-12-31 13:10:14.398 INFO 78104 --- [ad | producer-1] o.a.k.c.p.internals.TransactionManager : [Producer clientId=producer-1] ProducerId set to 1002 with epoch 0
接收到发送的kafka消息258741369
接收到发送的kafka消息ConsumerRecord(topic = order, partition = 0, leaderEpoch = 0, offset = 5, CreateTime = 1672463414397, serialized key size = -1, serialized value size = 9, headers = RecordHeaders(headers = [], isReadOnly = false), key = null, value = 258741369)
消息发送成功,topic=order,partition=0,offset=5
6.集群搭建
kafka集群、listeners配置、broker&topic&partition(leader、follower)关系、消费问题(同步、异步、ack应答机制、缓冲区、消费者poll长轮询)_鸢尾の的博客-CSDN博客_kafka listeners配置
7.问题
报错{orderInfo=UNKNOWN_TOPIC_OR_PARTITION}
服务启动中修改了log文件的路径
解决方法:
将log文件路径删除,再次重新启动zookeeper和kafka ,两个log的文件目录要一致
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