如何在Ubuntu系统启动时自动启动Kafka？

Question

Kafka是否有正式的方式(例如init.d脚本)在系统启动时启动Kafka？

启动卡夫卡的唯一官方方法我见过:

nohup ~/kafka/bin/kafka-server-start.sh ~/kafka/config/server.properties > ~/kafka/kafka.log 2>&1 &

我试图使用@reboot任务,crontab -e但它没有启动Kafka.有些人还编写了自定义init.d

还有一些自定义的init.d脚本可用(例如一个,两个,三个),但它们都是不同的,我对init.d不够熟悉,无法理解哪一个,如果有的话.

如何在系统启动时启动Kafka？

Answer 1

以下是我如何配置Kafka在Ubuntu 14.04上自动启动:

sudo su
cp -R ~/kafka_2.11-0.10.0.1 /opt
ln -s /opt/kafka_2.11-0.10.0.1 /opt/kafka

将以下init脚本复制到/etc/init.d/kafka:

DAEMON_PATH=/opt/kafka/
PATH=$PATH:$DAEMON_PATH/bin

# See how we were called.
case "$1" in
  start)
        # Start daemon.
        echo "Starting Zookeeper";
        nohup $DAEMON_PATH/bin/zookeeper-server-start.sh -daemon /$DAEMON_PATH/config/zookeeper.properties 2> /dev/null && \
        echo "Starting Kafka";
        nohup $DAEMON_PATH/bin/kafka-server-start.sh -daemon /$DAEMON_PATH/config/server.properties 2> /dev/null
        ;;
  stop)
        # Stop daemons.
        echo "Shutting down Zookeeper";
        pid=`ps ax | grep -i 'org.apache.zookeeper.server' | grep -v grep | awk '{print $1}'`
        if [ -n "$pid" ]
          then
          kill -9 $pid
        else
          echo "Zookeeper was not Running"
        fi
        echo "Shutting down Kafka";
        pid=`ps ax | grep -i 'kafka.Kafka' | grep -v grep | awk '{print $1}'`
        if [ -n "$pid" ]
          then
          kill -9 $pid
        else
          echo "Kafka was not Running"
        fi
        ;;
  restart)
        $0 stop
        sleep 2
        $0 start
        ;;
  status)
        pid=`ps ax | grep -i 'org.apache.zookeeper.server' | grep -v grep | awk '{print $1}'`
        if [ -n "$pid" ]
          then
          echo "Zookeeper is Running as PID: $pid"
        else
          echo "Zookeeper is not Running"
        fi
        pid=`ps ax | grep -i 'kafka.Kafka' | grep -v grep | awk '{print $1}'`
        if [ -n "$pid" ]
          then
          echo "Kafka is Running as PID: $pid"
        else
          echo "Kafka is not Running"
        fi
        ;;
  *)
        echo "Usage: $0 {start|stop|restart|status}"
        exit 1
esac

exit 0

使用以下命令创建kafka服务:

chmod 755 /etc/init.d/kafka
update-rc.d kafka defaults

现在您应该可以像这样启动和停止kafka服务:

sudo service kafka start
sudo service kafka status
sudo service kafka stop

如果您想稍后删除Kafka服务,请运行update-rc.d -f kafka remove.

Answer 2

下载卡夫卡

cd /opt
sudo wget http://mirror.hosting90.cz/apache/kafka/2.5.0/kafka-2.5.0-src.tgz
sudo tar -zxvf kafka-2.5.0-src.tgz
sudo mv kafka-2.5.0-src kafka
sudo rm kafka-2.5.0-src.tgz
cd kafka
sudo ./gradlew jar -PscalaVersion=2.11.12

安装动物园管理员

sudo vi /etc/systemd/system/zookeeper.service

编辑zookeeper.service

[Unit]
Requires=network.target remote-fs.target
After=network.target remote-fs.target

[Service]
Type=simple
User=root
ExecStart=/opt/kafka/bin/zookeeper-server-start.sh opt/kafka/config/zookeeper.properties
ExecStop=/opt/kafka/bin/zookeeper-server-stop.sh
Restart=on-abnormal

[Install]
WantedBy=multi-user.target

启动动物园管理员

sudo systemctl enable zookeeper.service

sudo systemctl start zookeeper.service

sudo systemctl status zookeeper.service

活动（运行）

安装卡夫卡

sudo vi /etc/systemd/system/kafka.service

编辑 kafka.service

[Unit]
Requires=zookeeper.service
After=zookeeper.service

[Service]
Type=simple
User=root
ExecStart=/bin/sh -c '/opt/kafka/bin/kafka-server-start.sh /opt/kafka/config/server.properties > /opt/kafka/kafka.log 2>&1'
ExecStop=/opt/kafka/bin/kafka-server-stop.sh
Restart=on-abnormal

[Install]
WantedBy=multi-user.target

启动卡夫卡

sudo systemctl enable kafka.service

sudo systemctl start kafka.service

sudo systemctl status kafka.service

活动（运行）

测试 Kafka 工作

创建主题

sudo bin/kafka-topics.sh --describe --bootstrap-server localhost:9092 --topic test-topic

将消息放入主题

sudo bin/kafka-console-producer.sh --broker-list localhost:9092 --topic test-topic  
> test message1
> test messate2
^C

从主题读取消息

sudo bin/kafka-console-consumer.sh --bootstrap-server localhost:9092 --from-beginning --topic test-topic
test message1
test messate2
^C

Answer 3

一种简单的方法是使用systemd。您应注意，启动时尚未加载JAVA_HOME之类的环境变量，因此我们应将其引入系统。一个好的解决方案是创建一个名为的文件，profile并向其中添加所有必需的变量：

# /home/kafka/profile
JAVA_HOME=/opt/jdk8
KAFKA_HOME=/opt/kafka

假设您已经在path上安装了Kafka /opt/kafka，为了让Kafka在Ubuntu启动后自动运行（在Ubuntu 16.04和centOS7上进行了测试，我猜它在systemd的支持下可以在任何发行版上运行）执行以下命令：

sudo nano /etc/systemd/system/kafka.service  # open file to add service informations

现在将以下内容添加到文件中

[Unit]
Description=Kafka Daemon
Wants=syslog.target

# suppose you have a service named zookeeper that it start zookeeper and we want Kafka service run after the zookeeper service
After=zookeeper.service

[Service]    
Type=forking

# the user whom you want run the Kafka start and stop command under
User=kafka    

# the file path that contains envirnment variables
EnvironmentFile=/home/kafka/profile

# the directory that the commands will run there   
WorkingDirectory=/home/kafka/ 

# Kafka server start command
ExecStart=/opt/kafka/bin/kafka-server-start.sh -daemon /opt/kafka/config/server.properties

# Kafka server stop command
ExecStop=/opt/kafka/bin/kafka-server-stop.sh -daemon

TimeoutSec=30
Restart=on-failure

[Install]
WantedBy=multi-user.target

注意：由于Kafka在启动时需要Zookeeper进行连接，因此我以为我们也有Zookeeper服务，因此我将Kafka服务设置为在Zookeeper服务启动后运行。

现在，保存kafka.service文件后，只需运行以下命令即可创建Kafka服务的链接，该链接将在每次​​重启操作系统时启动：

sudo systemctl enable kafka

现在，您可以使用以下命令启动Kafka服务：

sudo systemctl start kafka.service

并检查服务状态：

sudo systemctl status kafka.service