Kafka是一种高吞吐的分布式发布订阅消息系统，能够替代传统的消息队列用于解耦合数据处理，缓存未处理消息等，同时具有更高的吞吐率，支持分区、多副本、冗余，因此被广泛用于大规模消息数据处理应用。Kafka支持Java及多种其它语言客户端，可与Hadoop、Storm、Spark等其它大数据工具结合使用。
本教程主要介绍Kafka在CentOS7上的安装和使用，包括功能验证和集群的简单配置。
2.环境准备 #hostnameipsoftwarenotes1 apollo.dt.com 192.168.56.181 kafka
zookeeper Kafka:
broker.id=181
2 artemis.dt.com 192.168.56.182 kafka
zookeeper kafka:
borker.id=182
3 uranus.dt.com 192.168.56.183 kafka
zookeeper kafka:
broker.id=183
3.安装JDK
Kafka使用Zookeeper来保存相关配置信息，Kafka及Zookeeper依赖Java环境，有关CentOS7.0安装JDK请参考：CentOS7 安装JDK1.8
4.安装配置zookeeper集群有关Zookeeper的集群请参考：CentOS7安装配置Zookeeper集群
5.下载Kafka 4.1.下载Kafka [dtadmin@apollo~]$ sudo wget .tuna.tsinghua.edu.cn/apache/kafka/0.10.2.1/kafka_2.11-0.10.2.1.tgz 6.Kafka集群安装与配置 6.1.安装Kafka #解压Kafka [root@apollo dtadmin]# sudo tar -zxvf kafka_2.11-0.10.2.1.tgz #移到目录/opt下 [root@apollo dtadmin]# sudo mv kafka_2.11-0.10.2.1 /opt/kafka 6.2.配置kafka环境变量 [root@apollo dtadmin]# vim /etc/profile #添加如下内容： KAFKA_HOME=/opt/kafka PATH=$PATH:$KAFKA_HOME/bin export PATH KAFKA_HOME 6.3.配置Kafka #创建日志存放目录 [root@apollo dtadmin]# cd /opt/kafka [root@apollo kafka]# mkdir -p log/kafka #修改配置文件/opt/kafka/config/server.properties [root@apollo dtadmin]# vim /opt/kafka/config/server.properties #修改内容如下： broker.id=181 delete.topic.enable=true listeners = PLAINTEXT://apollo.dt.com:9092 log.dirs=/opt/kafka/log/kafka zookeeper.connect=192.168.56.181:2181,192.168.56.182:2181,192.168.56.183:2181样例配置文件：
[root@apollo dtadmin]# vim /opt/kafka/config/server.properties ####### # 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 # # # # 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 ############################# # The id of the broker. This must be set to a unique integer for each broker. broker.id=181 port=9092 # Switch to enable topic deletion or not, default value is false delete.topic.enable=true ############################# Socket Server Settings ############################# # The address the socket server listens on. It will get the value returned from # java.net.InetAddress.getCanonicalHostName() if not configured. # FORMAT: # listeners = listener_name://host_name:port # EXAMPLE: listeners = PLAINTEXT://apollo.dt.com:9092 #listeners=PLAINTEXT://:9092 # Hostname and port the broker will advertise to producers and consumers. If not set, # it uses the value for "listeners" if configured. Otherwise, it will use the value # returned from java.net.InetAddress.getCanonicalHostName(). #advertised.listeners=PLAINTEXT://your.host.name:9092 # Maps listener names to security protocols, the default is for them to be the same. See the config documentation for more details #listener.security.protocol.map=PLAINTEXT:PLAINTEXT,SSL:SSL,SASL_PLAINTEXT:SASL_PLAINTEXT,SASL_SSL:SASL_SSL # 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 ############################# # A comma seperated list of directories under which to store log files log.dirs=/opt/kafka/log/kafka # The default number of log partitions per topic. More partitions allow greater # parallelism for consumption, but this will also result in more files across # the brokers. 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. # The minimum age of a log file to be eligible for deletion due to age 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 connection string (see zookeeper docs for details). # This is a comma separated host:port pairs, each corresponding to a zk # server. e.g. "127.0.0.1:3000,127.0.0.1:3001,127.0.0.1:3002". # You can also append an optional chroot string to the urls to specify the # root directory for all kafka znodes. zookeeper.connect=192.168.56.181:2181,192.168.56.182:2181,192.168.56.183:2181 # Timeout in ms for connecting to zookeeper zookeeper.connection.timeout.ms=6000