kafka 集群搭建步骤

大家好，又见面了，我是你们的朋友全栈君。

  kafka 集群的运行建立在 zookeeper 基础上，kafka 中的消息偏移量信息、kafka 集群信息、topic 等信息会被存储在 zookeeper 中。高版本的 kafka 自带了 zookeeper，本文使用独立的 zookeeper 集群部署 kafka 集群。前期准备见《Linux 环境下，搭建 ZooKeeper 集群》。

一、下载 kafka

  kafka 官网：

• http://kafka.apache.org/
• http://kafka.apache.org/downloads

  本文下载的是 kafka_2.13-2.8.1.tgz。将上述文件分别上传至三台服务器 10.201.42.13、10.201.42.14、10.201.42.26 的 /home/cpctest 路径下。

  分别在三台服务器上解压文件：

[cpctest@vm-10-201-42-13 ~]$ tar -zxvf kafka_2.13-2.8.1.tgz

[cpctest@vm-10-201-42-13 ~]$ cd kafka_2.13-2.8.1/
[cpctest@vm-10-201-42-13 kafka_2.13-2.8.1]$ ll
total 48
drwxr-xr-x 3 cpctest app  4096 Sep 14 21:09 bin
drwxr-xr-x 3 cpctest app  4096 Feb 10 15:50 config
drwxr-xr-x 2 cpctest app  8192 Feb 10 14:24 libs
-rw-r--r-- 1 cpctest app 14520 Sep 14 21:03 LICENSE
drwxr-xr-x 2 cpctest app  4096 Sep 14 21:09 licenses
drwxr-xr-x 2 cpctest app  4096 Feb 10 16:00 logs
-rw-r--r-- 1 cpctest app   953 Sep 14 21:03 NOTICE
drwxr-xr-x 2 cpctest app    43 Sep 14 21:09 site-docs
[cpctest@vm-10-201-42-13 kafka_2.13-2.8.1]$ cd config/
[cpctest@vm-10-201-42-13 config]$ ll
total 72
-rw-r--r-- 1 cpctest app  906 Sep 14 21:03 connect-console-sink.properties
-rw-r--r-- 1 cpctest app  909 Sep 14 21:03 connect-console-source.properties
-rw-r--r-- 1 cpctest app 5321 Sep 14 21:03 connect-distributed.properties
-rw-r--r-- 1 cpctest app  883 Sep 14 21:03 connect-file-sink.properties
-rw-r--r-- 1 cpctest app  881 Sep 14 21:03 connect-file-source.properties
-rw-r--r-- 1 cpctest app 2247 Sep 14 21:03 connect-log4j.properties
-rw-r--r-- 1 cpctest app 2540 Sep 14 21:03 connect-mirror-maker.properties
-rw-r--r-- 1 cpctest app 2262 Sep 14 21:03 connect-standalone.properties
-rw-r--r-- 1 cpctest app 1221 Sep 14 21:03 consumer.properties
drwxr-xr-x 2 cpctest app   98 Sep 14 21:03 kraft
-rw-r--r-- 1 cpctest app 4674 Sep 14 21:03 log4j.properties
-rw-r--r-- 1 cpctest app 1925 Sep 14 21:03 producer.properties
-rw-r--r-- 1 cpctest app 7492 Feb 10 15:50 server.properties
-rw-r--r-- 1 cpctest app 1032 Sep 14 21:03 tools-log4j.properties
-rw-r--r-- 1 cpctest app 1169 Sep 14 21:03 trogdor.conf
-rw-r--r-- 1 cpctest app 1205 Sep 14 21:03 zookeeper.properties

二、创建 kafka 数据存放目录

  分别在三台服务器的以下路径创建 kafka 的数据存放目录：

[cpctest@vm-10-201-42-13 ~]$ pwd
/home/cpctest
[cpctest@vm-10-201-42-13 ~]$ mkdir kafkalogs
[cpctest@vm-10-201-42-13 ~]$ cd kafkalogs/
[cpctest@vm-10-201-42-13 kafkalogs]$ pwd
/home/cpctest/kafkalogs

三、修改配置文件

  在 10.201.42.13 服务器上，编辑 /home/cpctest/kafka_2.13-2.8.1/config/server.properties 文件，编辑后的文件内容如下所示：

# 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 #############################

# The id of the broker. This must be set to a unique integer for each broker.
# 每个broker在集群中的唯一标识，不能重复
broker.id=0
# 端口
port=9092
# broker主机地址
host.name=10.201.42.13

############################# 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://your.host.name: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 that the server uses for receiving requests from the network and sending responses to the network
# broker处理消息的线程数
num.network.threads=3

# The number of threads that the server uses for processing requests, which may include disk I/O
# broker处理磁盘io的线程数
num.io.threads=8

# The send buffer (SO_SNDBUF) used by the socket server
# socket发送数据缓冲区
socket.send.buffer.bytes=102400

# The receive buffer (SO_RCVBUF) used by the socket server
# socket接收数据缓冲区
socket.receive.buffer.bytes=102400

# The maximum size of a request that the socket server will accept (protection against OOM)
# socket接收请求最大值
socket.request.max.bytes=104857600


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

# A comma separated list of directories under which to store log files
# kafka数据存放目录位置，多个位置用逗号隔开
log.dirs=/home/cpctest/kafkalogs

# 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.
# topic默认的分区数
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.
# 恢复线程数
num.recovery.threads.per.data.dir=1

############################# Internal Topic Settings  #############################
# The replication factor for the group metadata internal topics "__consumer_offsets" and "__transaction_state"
# For anything other than development testing, a value greater than 1 is recommended to ensure availability such as 3.
# 默认副本数
offsets.topic.replication.factor=1
transaction.state.log.replication.factor=1
transaction.state.log.min.isr=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 excessive 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
# 消息日志最大存储时间，这里是7天
log.retention.hours=168

# A size-based retention policy for logs. Segments are pruned from the log unless the remaining
# segments 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.
# 每个日志分段文件大小，这里是1g
log.segment.bytes=1073741824

# The interval at which log segments are checked to see if they can be deleted according
# to the retention policies
# 消息日志文件大小检查间隔时间
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集群地址
zookeeper.connect=10.201.42.13:2181,10.201.42.14:2181,10.201.42.26:2181

# Timeout in ms for connecting to zookeeper
# zookeeper连接超时时间
zookeeper.connection.timeout.ms=6000


############################# Group Coordinator Settings #############################

# The following configuration specifies the time, in milliseconds, that the GroupCoordinator will delay the initial consumer rebalance.
# The rebalance will be further delayed by the value of group.initial.rebalance.delay.ms as new members join the group, up to a maximum of max.poll.interval.ms.
# The default value for this is 3 seconds.
# We override this to 0 here as it makes for a better out-of-the-box experience for development and testing.
# However, in production environments the default value of 3 seconds is more suitable as this will help to avoid unnecessary, and potentially expensive, rebalances during application startup.
group.initial.rebalance.delay.ms=0

  分别将上述文件 server.properties 远程拷贝至服务器 10.201.42.14 和 2181,10.201.42.26：

[cpctest@vm-10-201-42-14 config]$ scp cpctest@10.201.42.13:/home/cpctest/kafka_2.13-2.8.1/config/server.properties .

[cpctest@vm-10-201-42-26 config]$ scp cpctest@10.201.42.13:/home/cpctest/kafka_2.13-2.8.1/config/server.properties .

  在 10.201.42.14 上修改 server.properties 文件：

# 每个broker在集群中的唯一标识，不能重复
broker.id=1
# 端口
port=9092
# broker主机地址
host.name=10.201.42.14

  在 10.201.42.26 上修改 server.properties 文件：

# 每个broker在集群中的唯一标识，不能重复
broker.id=2
# 端口
port=9092
# broker主机地址
host.name=10.201.42.26

四、启动 kafka 集群

  尝试在第一台节点执行如下命令，启动 kafka ，看看是否报错：

[cpctest@vm-10-201-42-13 bin]$ ./kafka-server-start.sh /home/cpctest/kafka_2.13-2.8.1/config/server.properties

  启动过程没有报错，分别在三台节点执行如下命令，启动 kafka 集群。-daemon，以后台服务方式启动，后面跟的是配置文件：

[cpctest@vm-10-201-42-13 bin]$ ./kafka-server-start.sh -daemon /usr/local/kafka/kafka_2.11-1.0.0/config/server.properties

  查看是否有 kafka 进程：

[cpctest@vm-10-201-42-13 bin]$ jps
26757 jar
26615 Jps
25244 Kafka
24125 QuorumPeerMain
[cpctest@vm-10-201-42-13 bin]$ ps -ef|grep kafka

  初步看来，kafka 进程启动成功。集群是否搭建成功，可以进一步使用一些 kafka 的操作命令来验证，例如创建主题命令，可以参考《kafka 常用操作命令》。