Kafka集群的安装部署和实践应用

Kafka介绍

Kafka是一种高吞吐量的分布式发布订阅消息系统,有如下特性:

  • 通过O(1)的磁盘数据结构提供消息的持久化,这种结构对于即使数以TB的消息存储也能够保持长时间的稳定性能。
  • 高吞吐量:即使是非常普通的硬件Kafka也可以支持每秒数百万的消息。
  • 支持通过Kafka服务器和消费机集群来分区消息。
  • 支持Hadoop并行数据加载。

消息队列的作用

  • 应用程序解耦并行处理
  • 顺序保证
  • 高吞吐率
  • 高容错、高可用
  • 可扩展
  • 峰值处理


    Kafka集群.png

kafka原理

Kafka集群由多个实例组成,每个节点称为Broker,对消息保存时根据Topic进行归类
一个Topic可以被划分为多个Partition每个Partition可以有多个副本。

Kafka原理图01.png

Partition内顺序存储,写入新消息采用追加的方式,消费消息采用FIFO的方式顺序拉取消息
一个Topic可以有多个分区,Kafka只保证同一个分区内有序,不保证Topic整体(多个分区之间)有序

kafka原理图02.png

Consumer Group(CG),为了加快读取速度,多个consumer可以划分为一个组,并行消费一个Toic,一个Topic可以由多个CG订阅,多个CG之间是平等的,同一个CG内可以有一个或多个consumer,同一个CG内的consumer之间是竞争 关系,一个消息在一个CG内的只能被一个consumer消费


kafka原理图03.png

一、Kafka集群部署

集群规划清单

名称 节点 说明 节点名
Broker01 192.168.43.22 kafka节点01 hadoop03
Broker02 192.168.43.23 kafka节点02 hadoop04
Broker03 192.168.43.24 kafka节点03 hadoop05
Zookeeper 192.168.43.20/21/22 Zookeeper集群节点 hadoop01/hadoop02/hadoop03

1.下载Kafka安装包,并解压安装

[root@hadoop03 kafka_2.11-0.10.2.1]# ll
总用量 52
drwxr-xr-x. 3 hadoop hadoop  4096 4月  22 2017 bin
drwxr-xr-x. 2 hadoop hadoop  4096 4月  22 2017 config
drwxr-xr-x. 2 root   root     152 1月  20 18:57 kafka-logs
drwxr-xr-x. 2 hadoop hadoop  4096 1月  20 18:43 libs
-rw-r--r--. 1 hadoop hadoop 28824 4月  22 2017 LICENSE
drwxr-xr-x. 2 root   root    4096 1月  20 23:07 logs
-rw-r--r--. 1 hadoop hadoop   336 4月  22 2017 NOTICE
drwxr-xr-x. 2 hadoop hadoop    47 4月  22 2017 site-docs

2.创建软链接

[root@hadoop03 kafka_2.11-0.10.2.1]# ln -s /home/hadoop/apps/kafka_2.11-0.10.2.1 /usr/local/kafka

3.创建日志文件夹

[root@hadoop03 kafka]# pwd
/usr/local/kafka
[root@hadoop03 kafka]# mkdir kafka-logs/

4.配置服务启动信息

在/usr/local/kafka/config目录下修改server.properties文件,具体内容如下:

# Licensed to the Apache Software Foundation (ASF) under one or more
# contributor license agreements.  See the NOTICE file distributed with
# this work for additional information regarding copyright ownership.
# The ASF licenses this file to You under the Apache License, Version 2.0
# (the "License"); you may not use this file except in compliance with
# the License.  You may obtain a copy of the License at
#
#    http://www.apache.org/licenses/LICENSE-2.0
#
# Unless required by applicable law or agreed to in writing, software
# distributed under the License is distributed on an "AS IS" BASIS,
# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
# See the License for the specific language governing permissions and
# limitations under the License.

# see kafka.server.KafkaConfig for additional details and defaults

############################# Server Basics #############################

#每个borker的id是唯一的,多个broker要设置不同的id
broker.id=0

#访问端口号
port=9092

#访问地址
host.name=192.168.43.22

#允许删除topic
delete.topic.enable=true


# The number of threads handling network requests
num.network.threads=3

# The number of threads doing disk I/O
num.io.threads=8

# The send buffer (SO_SNDBUF) used by the socket server
socket.send.buffer.bytes=102400

# The receive buffer (SO_RCVBUF) used by the socket server
socket.receive.buffer.bytes=102400

# The maximum size of a request that the socket server will accept (protection against OOM)
socket.request.max.bytes=104857600


############################# Log Basics #############################

#存储数据路径,默认是在/tmp目录下,需要修改
log.dirs=/usr/local/kafka/kafka-logs

#创建topic默认分区数
num.partitions=1

# The number of threads per data directory to be used for log recovery at startup and flushing at shutdown.
# This value is recommended to be increased for installations with data dirs located in RAID array.
num.recovery.threads.per.data.dir=1

############################# Log Flush Policy #############################

# Messages are immediately written to the filesystem but by default we only fsync() to sync
# the OS cache lazily. The following configurations control the flush of data to disk.
# There are a few important trade-offs here:
#    1. Durability: Unflushed data may be lost if you are not using replication.
#    2. Latency: Very large flush intervals may lead to latency spikes when the flush does occur as there will be a lot of data to flush.
#    3. Throughput: The flush is generally the most expensive operation, and a small flush interval may lead to exceessive seeks.
# The settings below allow one to configure the flush policy to flush data after a period of time or
# every N messages (or both). This can be done globally and overridden on a per-topic basis.

# The number of messages to accept before forcing a flush of data to disk
#log.flush.interval.messages=10000

# The maximum amount of time a message can sit in a log before we force a flush
#log.flush.interval.ms=1000

############################# Log Retention Policy #############################

# The following configurations control the disposal of log segments. The policy can
# be set to delete segments after a period of time, or after a given size has accumulated.
# A segment will be deleted whenever *either* of these criteria are met. Deletion always happens
# from the end of the log.

#数据保存时间,默认7天,单位小时
log.retention.hours=168

# A size-based retention policy for logs. Segments are pruned from the log as long as the remaining
# segments don't drop below log.retention.bytes. Functions independently of log.retention.hours.
#log.retention.bytes=1073741824

# The maximum size of a log segment file. When this size is reached a new log segment will be created.
log.segment.bytes=1073741824

# The interval at which log segments are checked to see if they can be deleted according
# to the retention policies
log.retention.check.interval.ms=300000

############################# Zookeeper #############################

#zookeeper地址,多个地址用逗号隔开
zookeeper.connect=192.168.43.20:2181,192.168.43.21:2181,192.168.43.22:2181

# Timeout in ms for connecting to zookeeper
zookeeper.connection.timeout.ms=6000

5.拷贝文件信息到Broker02/Broker03节点上

scp -r /home/hadoop/apps/kafka_2.11-0.10.2.1 hadoop@node04:/home/hadoop/apps/
scp -r /home/hadoop/apps/kafka_2.11-0.10.2.1 hadoop@node04:/home/hadoop/apps/

6.修改Broker02和Broker03信息

创建软连接

[root@hadoop03 kafka_2.11-0.10.2.1]# ln -s /home/hadoop/apps/kafka_2.11-0.10.2.1 /usr/local/kafka

修改配置文件server.properties信息

broker.id=1
host.name=192.168.43.23

修改Broker03节点server.properties信息

broker.id=2
host.name=192.168.43.24

7.分别启动Broker01/Broker02/Broker03

以后台进程的方式启动Kafka

[root@hadoop03 bin]#./kafka-server-start.sh -daemon config/server.properties

二、Kafka应用实践

1.创建主题

[root@hadoop03 bin]# pwd
/usr/local/kafka/bin
[root@hadoop03 bin]# ./kafka-topics.sh --create --zookeeper 192.168.43.20:2181 --replication-factor 2 --partitions 3 --topic topicnewtest1
Created topic "topicnewtest1".

2.查看主题

[root@hadoop03 bin]# ./kafka-topics.sh  --list --zookeeper 192.168.43.20:2181
topicnewtest1

3.查看主题信息

[root@hadoop03 bin]# ./kafka-topics.sh --describe --zookeeper 192.168.43.20:2181 --topic topicnewtest1
Topic:topicnewtest1 PartitionCount:3    ReplicationFactor:2 Configs:
    Topic: topicnewtest1    Partition: 0    Leader: 2   Replicas: 2,0   Isr: 2,0
    Topic: topicnewtest1    Partition: 1    Leader: 0   Replicas: 0,1   Isr: 0,1
    Topic: topicnewtest1    Partition: 2    Leader: 1   Replicas: 1,2   Isr: 1,2

4.删除主题

[root@hadoop03 bin]# ./kafka-topics.sh --delete --zookeeper 192.168.43.20:2181 --topic topicnewtest1
Topic topicnewtest1 is marked for deletion.
Note: This will have no impact if delete.topic.enable is not set to true.

5.增加分区

[root@hadoop03 bin]# ./kafka-topics.sh --alter --zookeeper 192.168.43.20:2181 --topic topicnewtest1 --partitions 5
WARNING: If partitions are increased for a topic that has a key, the partition logic or ordering of the messages will be affected
Adding partitions succeeded!
[root@hadoop03 bin]# ./kafka-topics.sh --describe --zookeeper 192.168.43.20:2181 --topic topicnewtest1
Topic:topicnewtest1 PartitionCount:5    ReplicationFactor:2 Configs:
    Topic: topicnewtest1    Partition: 0    Leader: 1   Replicas: 1,0   Isr: 1,0
    Topic: topicnewtest1    Partition: 1    Leader: 2   Replicas: 2,1   Isr: 2,1
    Topic: topicnewtest1    Partition: 2    Leader: 0   Replicas: 0,2   Isr: 0,2
    Topic: topicnewtest1    Partition: 3    Leader: 1   Replicas: 1,2   Isr: 1,2
    Topic: topicnewtest1    Partition: 4    Leader: 2   Replicas: 2,0   Isr: 2,0

6.使用kafka自带的生产者客户端脚本和消费端脚本

使用kafka自带的生产者客户端脚本

[root@hadoop03 bin]# ./kafka-console-producer.sh --broker-list 192.168.43.22:9092,192.168.43.23:9092 --topic topicnewtest1

使用kafka自带的消费者客户端脚本

[root@hadoop04 bin]# ./kafka-console-consumer.sh --zookeeper 192.168.43.20:2181 --from-beginning --topic topicnewtest1

在生成端发送消息,可以在消费看到消息

7.使用Java访问Kafka产生消息和消费消息

  • Producer
package cn.chinahadoop.client;

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

import java.util.Date;
import java.util.Properties;
import java.util.Random;

/**
 * Kafka生产端
 * @author Zhangyongliang
 */
public class ProducerClient {
    public static void main(String[] args){
        Properties props = new Properties();
        //kafka broker列表
        props.put("bootstrap.servers", "192.168.43.22:9092,192.168.43.23:9092,192.168.43.24:9092");
        //acks=1表示Broker接收到消息成功写入本地log文件后向Producer返回成功接收的信号,不需要等待所有的Follower全部同步完消息后再做回应
        props.put("acks", "1");
        //key和value的字符串序列化类
        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<String, String>(props);
        //用户产生随机数,模拟消息生成
        Random rand = new Random();
        for(int i = 0; i < 20; i++) {
            //通过随机数产生一个ip地址作为key发送出去
            String ip = "192.168.1." + rand.nextInt(255);
            long runtime = new Date().getTime();
            //组装一条消息内容
            String msg = runtime + "---" + ip;
            try {
                Thread.sleep(1000);
            } catch (InterruptedException e) {
                e.printStackTrace();
            }
            System.out.println("send to kafka->key:" + ip + " value:" + msg);
            //向kafka topictest1主题发送消息
            producer.send(new ProducerRecord<String, String>("topicnewtest1", ip, msg));
        }
        producer.close();
    }
}
  • ConSumer
package com.yongliang.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.ArrayList;
import java.util.Arrays;
import java.util.List;
import java.util.Properties;

/**
 * Kafka消费端
 * @author Zhangyongliang
 */
public class ConsumerClient {
    /**
     * 手动提交偏移量
     */
    public static void manualCommintClient(){
        Properties props = new Properties();
        //kafka broker列表
        props.put("bootstrap.servers", "192.168.43.22:9092,192.168.43.23:9092,192.168.43.24:9092");
        //consumer group id
        props.put("group.id", "yongliang");
        //手动提交offset
        props.put("enable.auto.commit", "false");
        //earliest表示从最早的偏移量开始拉取,latest表示从最新的偏移量开始拉取,none表示如果没有发现该Consumer组之前拉取的偏移量则抛异常。默认值latest。
        props.put("auto.offset.reset", "earliest");
        //key和value的字符串反序列化类
        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<String, String>(props);
        //consumer订阅topictest1主题,同时消费多个主题用逗号隔开
        consumer.subscribe(Arrays.asList("topicnewtest1"));
        //每次最少处理10条消息后才提交
        final int minBatchSize = 10;
        //用于保存消息的list
        List<ConsumerRecord<String, String>> bufferList = new ArrayList<ConsumerRecord<String, String>>();
        while (true) {
            System.out.println("--------------start pull message---------------" );
            long starttime = System.currentTimeMillis();
            //poll方法需要传入一个超时时间,当没有可以拉取的消息时先等待,
            //如果已到超时时间还没有可以拉取的消息则进行下一轮拉取,单位毫秒
            ConsumerRecords<String, String> records = consumer.poll(1000);
            long endtime = System.currentTimeMillis();
            long tm = (endtime - starttime) / 1000;
            System.out.println("--------------end pull message and times=" + tm + "s -------------");

            for (ConsumerRecord<String, String> record : records) {
                System.out.printf("partition = %d, offset = %d, key = %s, value = %s%n", record.partition(), record.offset(), record.key(), record.value());
                bufferList.add(record);
            }
            System.out.println("--------------buffer size->" + bufferList.size());
            //如果读取到的消息满了10条, 就进行处理
            if (bufferList.size() >= minBatchSize) {
                System.out.println("******start deal message******");
                try {
                    //当前线程睡眠1秒钟,模拟消息处理过程
                    Thread.sleep(1000);
                } catch (InterruptedException e) {
                    e.printStackTrace();
                }

                System.out.println("manual commint offset start...");
                //处理完之后进行提交
                consumer.commitSync();
                //清除list, 继续接收
                bufferList.clear();
                System.out.println("manual commint offset end...");
            }
        }
    }

    /**
     * 自动提交偏移量
     */
    public static void autoCommintClient(){
        Properties props = new Properties();
        //kafka broker列表
        props.put("bootstrap.servers", "192.168.43.22:9092,192.168.43.23:9092,192.168.43.24:9092");
        props.put("group.id", "newConsumerGroup");
        //自动提交
        props.put("enable.auto.commit", "true");
        //自动提交时间间隔1000毫秒
        props.put("auto.commit.interval.ms", "1000");
        //earliest表示从最早的偏移量开始拉取,latest表示从最新的偏移量开始拉取,none表示如果没有发现该Consumer组之前拉取的偏移量则抛异常。默认值latest。
        props.put("auto.offset.reset", "earliest");
        //key和value的字符串反序列化类
        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<String, String>(props);
        //consumer订阅topictest1主题,同时消费多个主题用逗号隔开
        consumer.subscribe(Arrays.asList("topicnewtest1"));
        while (true) {
            //poll方法需要传入一个超时时间,当没有可以拉取的消息时先等待,
            //如果已到超时时间还没有可以拉取的消息则进行下一轮拉取,单位毫秒
            ConsumerRecords<String, String> records = consumer.poll(1000);
            //处理拉取过来的消息
            for (ConsumerRecord<String, String> record : records){
                System.out.printf("partition = %d, offset = %d, key = %s, value = %s%n", record.partition(), record.offset(), record.key(), record.value());
            }

        }
    }
    public static void main(String[] args){
        //自动提交offset
//        autoCommintClient();
        //手动提交offset
        manualCommintClient();
    }
}

推荐阅读更多精彩内容