配置systemctl（zookeeper、hadoop、redis）

==背景==

给公司搭建了一个建议的大数据平台，组件包括zookeeper、hadoop、flink、influxdb、redis、mysql、rocketmq

因为zookeeper、hadoop是平台的基础组件，打算配置systemctl守护进程，用来挂掉自动重启，以减少运维负担。

 

==规划==

1、每台机器设置service文件的管理文件夹：/home/radmin/rexel-dev

2、文件组成，为每个service生成两个文件：xxx.service及xxx.service.run。.run是.service需要执行的脚本，负责环境依赖

3、软连接：在systemctl目录下建立软连接，连接到rexel-dev下的具体文件

4、所有.run文件赋予777权限。

 

==准备==

1、创建pid文件存放路径

for i in {1..3}; do ssh vm$i mkdir -p /home/radmin/data/pids/hadoop; done

 

2、创建service文件存放路径

for i in {1..3}; do ssh vm$i mkdir -p /home/radmin/rexel-dev; done

 

3、配置系统环境变量

export HADOOP_PID_DIR=/home/radmin/data/pids/hadoop
export YARN_PID_DIR=/home/radmin/data/pids/hadoop

 

==zookeeper==

1、文件规划

rexel-zookeeper.service
rexel-zookeeper.service.run

 

2、配置run文件

文件：rexel-zookeeper.service.run

#!/bin/bash
source /etc/profile
/home/radmin/zookeeper-3.5.6/bin/zkServer.sh start

 

3、配置service文件

文件：rexel-zookeeper.service

[Unit]
Description=Zookeeper Service
After=network.target
ConditionPathExists=/home/radmin/zookeeper-3.5.6/conf/zoo.cfg

[Service]
Type=forking
PIDFile=/home/radmin/data/zk/dataDir/zookeeper_server.pid
ExecStart=/home/radmin/rexel-dev/rexel-zookeeper.service.run
Restart=always

[Install]
WantedBy=multi-user.target

 

4、配置软连接

命令：

ln -s /home/radmin/rexel-dev/rexel-zookeeper.service /usr/lib/systemd/system/rexel-zookeeper.service

 

5、加载生效

命令：

systemctl daemon-reload

 

6、启动服务

命令：

systemctl status rexel-zookeeper.service

 

【小贴士】

任何增加、修改或删除systemctl，都需要执行systemctl daemon-reload命令，使修改生效。

 

【小插曲】

service启动失败，通过journalctl -xe命令查看日志，发现提示

Can't open PID file /home/radmin/data/pid/zookeeper.pid (yet?) after start: No such file or directory

发现原因是配置的pid文件路径不正确，将pid文件的路径和zoo.cfg中的dataDir路径一致，重新启动service之后，恢复正常。

 

==hadoop==

1、文件规划

rexel-hdfs-journalnode.service
rexel-hdfs-journalnode.service.run
rexel-hdfs-namenode.service
rexel-hdfs-namenode.service.run
rexel-hdfs-zkfc.service
rexel-hdfs-zkfc.service.run
rexel-hdfs-datanode.service
rexel-hdfs-datanode.service.run
rexel-yarn-nodemanager.service
rexel-yarn-nodemanager.service.run
rexel-yarn-resourcemanager.service
rexel-yarn-resourcemanager.service.run

 

2、配置run文件

文件1：rexel-hdfs-journalnode.service.run

#!/bin/bash
source /etc/profile
/home/radmin/hadoop-2.8.3/sbin/hadoop-daemon.sh start journalnode

 

文件2：rexel-hdfs-namenode.service.run

#!/bin/bash
source /etc/profile
/home/radmin/hadoop-2.8.3/sbin/hadoop-daemon.sh start namenode

 

文件3：rexel-hdfs-zkfc.service.run

#!/bin/bash
source /etc/profile
/home/radmin/hadoop-2.8.3/sbin/hadoop-daemon.sh start zkfc

 

文件4：rexel-hdfs-datanode.service.run

#!/bin/bash
source /etc/profile
/home/radmin/hadoop-2.8.3/sbin/hadoop-daemon.sh start datanode

 

文件5：rexel-yarn-resourcemanager.service.run

#!/bin/bash
source /etc/profile
/home/radmin/hadoop-2.8.3/sbin/yarn-daemon.sh start resourcemanager

 

文件6：rexel-yarn-nodemanager.service.run

#!/bin/bash
source /etc/profile
/home/radmin/hadoop-2.8.3/sbin/yarn-daemon.sh start nodemanager

 

3、配置service文件

文件1：rexel-hdfs-journalnode.service

[Unit]
Description=HDFS Journalnode Service
After=network.target

[Service]
Type=forking
PIDFile=/home/radmin/data/pids/hadoop/hadoop-root-journalnode.pid
ExecStart=/home/radmin/rexel-dev/rexel-hdfs-journalnode.service.run
Restart=always

[Install]
WantedBy=multi-user.target

 

文件2：rexel-hdfs-namenode.service

[Unit]
Description=HDFS Namenode Service
After=network.target

[Service]
Type=forking
PIDFile=/home/radmin/data/pids/hadoop/hadoop-root-namenode.pid
ExecStart=/home/radmin/rexel-dev/rexel-hdfs-namenode.service.run
Restart=always

[Install]
WantedBy=multi-user.target

 

文件3：rexel-hdfs-datanode.service

[Unit]
Description=HDFS Datanode Service
After=network.target

[Service]
Type=forking
PIDFile=/home/radmin/data/pids/hadoop/hadoop-root-datanode.pid
ExecStart=/home/radmin/rexel-dev/rexel-hdfs-datanode.service.run
Restart=always

[Install]
WantedBy=multi-user.target

 

文件4：rexel-hdfs-zkfc.service

[Unit]
Description=HDFS ZKFC Service
After=network.target

[Service]
Type=forking
PIDFile=/home/radmin/data/pids/hadoop/hadoop-root-zkfc.pid
ExecStart=/home/radmin/rexel-dev/rexel-hdfs-zkfc.service.run
Restart=always

[Install]
WantedBy=multi-user.target

 

文件5：rexel-yarn-resourcemanager.service

[Unit]
Description=Yarn Resourcemanager Service
After=network.target

[Service]
Type=forking
PIDFile=/home/radmin/data/pids/hadoop/yarn-root-resourcemanager.pid
ExecStart=/home/radmin/rexel-dev/rexel-yarn-resourcemanager.service.run
Restart=always

[Install]
WantedBy=multi-user.target

 

文件6：rexel-yarn-nodemanager.service

[Unit]
Description=Yarn Nodemanager Service
After=network.target

[Service]
Type=forking
PIDFile=/home/radmin/data/pids/hadoop/yarn-root-nodemanager.pid
ExecStart=/home/radmin/rexel-dev/rexel-yarn-nodemanager.service.run
Restart=always

[Install]
WantedBy=multi-user.target

 

4、配置软连接

命令：

ln -s /home/radmin/rexel-dev/rexel-hdfs-journalnode.service /usr/lib/systemd/system/rexel-hdfs-journalnode.service
ln -s /home/radmin/rexel-dev/rexel-hdfs-namenode.service /usr/lib/systemd/system/rexel-hdfs-namenode.service
ln -s /home/radmin/rexel-dev/rexel-hdfs-zkfc.service /usr/lib/systemd/system/rexel-hdfs-zkfc.service
ln -s /home/radmin/rexel-dev/rexel-hdfs-datanode.service /usr/lib/systemd/system/rexel-hdfs-datanode.service
ln -s /home/radmin/rexel-dev/rexel-yarn-resourcemanager.service /usr/lib/systemd/system/rexel-yarn-resourcemanager.service
ln -s /home/radmin/rexel-dev/rexel-yarn-nodemanager.service /usr/lib/systemd/system/rexel-yarn-nodemanager.service

 

5、加载生效

命令：

systemctl daemon-reload

 

6、启动服务

命令：

systemctl start rexel-hdfs-journalnode.service
systemctl start rexel-hdfs-namenode.service
systemctl start rexel-hdfs-zkfc.service
systemctl start rexel-hdfs-datanode.service
systemctl start rexel-yarn-resourcemanager.service
systemctl start rexel-yarn-nodemanager.service

 

【小插曲】

和zookeeper一样，提示了找不到pid文件的错误。

解决办法：在系统环境变量中配置HADOOP_PID_DIR，YARN_PID_DIR然后修改一下service文件中pid文件的路径，重新启动服务即可。

 

==Redis==

1、文件规划

rexel-redis.service
rexel-redis.service.run

 

2、配置run文件

文件：rexel-redis.service.run

#!/bin/bash
source /etc/profile
/home/radmin/redis-5.0.8/src/redis-server /home/radmin/redis-5.0.8/redis.conf

 

3、配置service文件

文件：rexel-redis.service

[Unit]
Description=Redis Service
After=network.target

[Service]
Type=forking
PIDFile=/home/radmin/data/pids/redis_8793.pid
ExecStart=/home/radmin/rexel-dev/rexel-redis.service.run
Restart=always

[Install]
WantedBy=multi-user.target

 

【小贴士】

redis设置了默认的pid文件路径：/var/run/redis_6379.pid，为了方便管理，我重新定义了pidfile的配置。

相应的在rexel-redis.service文件中的

 

4、配置软连接

命令：

ln -s /home/radmin/rexel-dev/rexel-redis.service /usr/lib/systemd/system/rexel-redis.service

 

5、加载生效

命令：

systemctl daemon-reload

 

6、启动服务

命令：

systemctl start rexel-redis.service

 

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