一、查看 相关服务

1.查看 数据库 相关服务

        这里以mysql 和 redis 为例

（1）使用 ps 命令

        执行命令会列出，“mysql”、“redis”名称的进程

ps aux | grep redis

        示例：

root@spray:~# ps aux | grep mysql
mysql    1609816  0.2  8.9 1952752 712576 ?      Ssl  Apr02 140:10 /usr/sbin/mysqld
root     2443891  0.0  0.0   9032   656 pts/0    S+   09:52   0:00 grep --color=auto mysql
root@spray:~# ps aux | grep redis
root     2444309  0.0  0.0   9032   720 pts/0    S+   09:52   0:00 grep --color=auto redis
redis    3180910  0.1  0.1 270980 15708 ?        Ssl  Apr09  89:55 /usr/bin/redis-server 0.0.0.0:6379

（2）使用 systemctl 命令

        适用于systemd的系统，会显示redis的服务状态（包括是否 运行、已停止 或 其他状态）

 systemctl status redis-server

root@spray:~# systemctl status redis-server
● redis-server.service - Advanced key-value store
     Loaded: loaded (/lib/systemd/system/redis-server.service; disabled; vendor preset: enabled)
     Active: active (running) since Tue 2024-04-09 13:47:20 CST; 1 months 5 days ago
       Docs: http://redis.io/documentation,
             man:redis-server(1)
   Main PID: 3180910 (redis-server)
     Status: "Ready to accept connections"
      Tasks: 6 (limit: 9291)
     Memory: 15.9M
     CGroup: /system.slice/redis-server.service
             └─3180910 /usr/bin/redis-server 0.0.0.0:6379
Warning: journal has been rotated since unit was started, output may be incomplete.
root@spray:~# systemctl status mysql
● mysql.service - MySQL Community Server
     Loaded: loaded (/lib/systemd/system/mysql.service; enabled; vendor preset: enabled)
     Active: active (running) since Tue 2024-04-02 17:42:12 CST; 1 months 12 days ago
   Main PID: 1609816 (mysqld)
     Status: "Server is operational"
      Tasks: 46 (limit: 9291)
     Memory: 702.2M
     CGroup: /system.slice/mysql.service
             └─1609816 /usr/sbin/mysqld
Warning: journal has been rotated since unit was started, output may be incomplete.

（3）使用service命令

        不适用在较旧的systemd系统中

service redis-server status

root@spray:~# service redis-server status
● redis-server.service - Advanced key-value store
     Loaded: loaded (/lib/systemd/system/redis-server.service; disabled; vendor preset: enabled)
     Active: active (running) since Tue 2024-04-09 13:47:20 CST; 1 months 4 days ago
       Docs: http://redis.io/documentation,
             man:redis-server(1)
   Main PID: 3180910 (redis-server)
     Status: "Ready to accept connections"
      Tasks: 6 (limit: 9291)
     Memory: 16.0M
     CGroup: /system.slice/redis-server.service
             └─3180910 /usr/bin/redis-server 0.0.0.0:6379
Warning: journal has been rotated since unit was started, output may be incomplete.
root@spray:~# service mysql status
● mysql.service - MySQL Community Server
     Loaded: loaded (/lib/systemd/system/mysql.service; enabled; vendor preset: enabled)
     Active: active (running) since Tue 2024-04-02 17:42:12 CST; 1 months 11 days ago
   Main PID: 1609816 (mysqld)
     Status: "Server is operational"
      Tasks: 46 (limit: 9291)
     Memory: 702.6M
     CGroup: /system.slice/mysql.service
             └─1609816 /usr/sbin/mysqld
Warning: journal has been rotated since unit was started, output may be incomplete.