Linux服务与进程管理

一、服务管理

  • dnf -y install nginx 安装nginx服务器（端口号为80，使用tcp协议）
  • CentOS6版本通过service命令进行服务管理
  • CentOS7版本及以上通过systemctl命令进行服务管理
    • systemctl status xxx —> 查看xxx服务的状态
    • systemctl start xxx —> 启动xxx服务
    • systemctl stop xxx —> 停止xxx服务
    • systemctl restart xxx —> 重启xxx服务
    • systemctl reload xxx —> 重新加载xxx服务（重载过程中并不关闭服务）
    • systemctl enable xxx —> 设置xxx服务开机自启
    • systemctl disable xxx —> 禁止xxx服务开机自启
  • netstat 查询系统上的网络套接字连接情况（即查询端口情况）
    • netstat -anlpt 查看所有tcp协议的端口
    • netstat -anlpu 查看所有udp协议的端口
    • -a 查询所有端口
    • -n 禁止使用域名解析功能，提高查询速度
    • -l 仅显示监听的端口
    • -p 显示与端口有关的程序名和进程的pid
    • -t 显示与tcp协议有关的端口
    • -u 显示与udp协议有关的端口
  1. # 查看当前是否安装nginx
  2. [root@myserver ~]# rpm -qa | grep nginx
  4. # 安装nginx
  5. [root@myserver ~]# dnf -y install nginx
  6. Last metadata expiration check: 0:15:42 ago on Tue 28 Jul 2020 08:20:47 AM CST.
  7. Dependencies resolved.
  8. =======================================================================================
  9.  Package                 Arch   Version                                Repo       Size
  10. ......
  11.   nginx-mod-mail-1:1.14.1-9.module_el8.0.0+184+e34fea82.x86_64                         
  12.   nginx-mod-stream-1:1.14.1-9.module_el8.0.0+184+e34fea82.x86_64                       
  14. Complete!
  16. # 查看nginx是否安装成功
  17. [root@myserver ~]# rpm -qa | grep nginx
  18. nginx-mod-http-image-filter-1.14.1-9.module_el8.0.0+184+e34fea82.x86_64
  19. nginx-1.14.1-9.module_el8.0.0+184+e34fea82.x86_64
  20. nginx-mod-http-xslt-filter-1.14.1-9.module_el8.0.0+184+e34fea82.x86_64
  21. nginx-mod-stream-1.14.1-9.module_el8.0.0+184+e34fea82.x86_64
  22. nginx-filesystem-1.14.1-9.module_el8.0.0+184+e34fea82.noarch
  23. nginx-mod-mail-1.14.1-9.module_el8.0.0+184+e34fea82.x86_64
  24. nginx-all-modules-1.14.1-9.module_el8.0.0+184+e34fea82.noarch
  25. nginx-mod-http-perl-1.14.1-9.module_el8.0.0+184+e34fea82.x86_64
  27. # 查看nginx服务状态，按q键退出查看  -->  Active: inactive (dead)  -->  未启动
  28. [root@myserver ~]# systemctl status nginx
  29. ● nginx.service - The nginx HTTP and reverse proxy server
  30.    Loaded: loaded (/usr/lib/systemd/system/nginx.service; disabled; vendor preset: dis>
  31.    Active: inactive (dead)
  33. Jul 28 08:15:38 myserver systemd[1]: nginx.service: Unit cannot be reloaded because it>
  34. Jul 28 08:36:32 myserver systemd[1]: nginx.service: Unit cannot be reloaded because it>
  36. # 开启nginx服务
  37. [root@myserver ~]# systemctl start nginx.service 
  39. # 查看是否成功启动  -->  Active: active (running)  -->  已启动
  40. [root@myserver ~]# systemctl status nginx.service 
  41. ● nginx.service - The nginx HTTP and reverse proxy server
  42.    Loaded: loaded (/usr/lib/systemd/system/nginx.service; disabled; vendor preset: dis>
  43.    Active: active (running) since Tue 2020-07-28 08:56:39 CST; 12s ago
  44.   Process: 37270 ExecStart=/usr/sbin/nginx (code=exited, status=0/SUCCESS)
  45.   Process: 37268 ExecStartPre=/usr/sbin/nginx -t (code=exited, status=0/SUCCESS)
  46. ......
  48. # 停止nginx服务
  49. [root@myserver ~]# systemctl stop nginx.service 
  51. # 查看是否成功停止  -->  Active: inactive (dead)  -->  已停止
  52. [root@myserver ~]# systemctl status nginx.service 
  53. ● nginx.service - The nginx HTTP and reverse proxy server
  54.    Loaded: loaded (/usr/lib/systemd/system/nginx.service; disabled; vendor preset: dis>
  55.    Active: inactive (dead)
  56. ......
  58. # 重启nginx
  59. [root@myserver ~]# systemctl restart nginx.service 
  61. # 查看是否重启成功
  62. [root@myserver ~]# systemctl status nginx.service 
  63. ● nginx.service - The nginx HTTP and reverse proxy server
  64.    Loaded: loaded (/usr/lib/systemd/system/nginx.service; disabled; vendor preset: dis>
  65.    Active: active (running) since Tue 2020-07-28 08:59:31 CST; 11s ago
  66.   Process: 37393 ExecStart=/usr/sbin/nginx (code=exited, status=0/SUCCESS)
  67. ......
  69. # 重载nginx
  70. [root@myserver ~]# systemctl reload nginx.service 
  71. [root@myserver ~]# systemctl status nginx.service 
  72. ● nginx.service - The nginx HTTP and reverse proxy server
  73.    Loaded: loaded (/usr/lib/systemd/system/nginx.service; disabled; vendor preset: dis>
  74.    Active: active (running) since Tue 2020-07-28 08:59:31 CST; 1min 13s ago
  75.   Process: 37444 ExecReload=/bin/kill -s HUP $MAINPID (code=exited, status=0/SUCCESS)
  76. ......
  78. # 将nginx设为开机自启  -->  在/etc/systemd/system/multi-user.target.wants/文件夹下创建一个文件nginx.service（映射的是/etc/systemd/system/multi-user.target.wants/下的nginx.service文件，其是nginx服务的启动文件）
  79. [root@myserver ~]# systemctl enable nginx.service 
  80. Created symlink /etc/systemd/system/multi-user.target.wants/nginx.service → /usr/lib/systemd/system/nginx.service.
  82. # 关闭nginx开机自启  -->  将/etc/systemd/system/multi-user.target.wants/目录下的nginx.service文件删除
  83. [root@myserver ~]# systemctl disable nginx.service 
  84. Removed /etc/systemd/system/multi-user.target.wants/nginx.service.
  86. # 检测nginx服务是否在运行
  87. [root@myserver ~]# netstat -anlpt | grep 80
  88. tcp        0      0 0.0.0.0:80              0.0.0.0:*               LISTEN      37394/nginx: master 
  89. tcp6       0      0 :::80                   :::*                    LISTEN      37394/nginx: master

二、进程管理

  • top 查看系统所有进程
  • ps 查看进程的状态
    • a 显示现行终端机下的所有程序，包括其他用户的程序
    • u 以用户为主的格式来显示程序状况
    • x 显示所有程序，不以终端机来区分
  • kill 停止进程
    • kill -9 pid —> 强制杀死进程号为pid的进程
    • kill -15 pid —> 进程号为pid的进程执行完当前任务就停止
    • killall xxx —> 结束xxx服务的所有进程
  1. # 查看系统所有进程
  2. [root@myserver ~]# top
  3. top - 14:45:31 up  3:37,  1 user,  load average: 0.07, 0.06, 0.02
  4. Tasks: 334 total,   1 running, 332 sleeping,   0 stopped,   1 zombie
  5. %Cpu(s):  0.2 us,  0.6 sy,  0.0 ni, 98.9 id,  0.0 wa,  0.2 hi,  0.0 si,  0.0 st
  6. MiB Mem :   3752.0 total,   1032.9 free,   1588.6 used,   1130.5 buff/cache
  7. MiB Swap:   4044.0 total,   4044.0 free,      0.0 used.   1872.8 avail Mem 
  9.     PID USER      PR  NI    VIRT    RES    SHR S  %CPU  %MEM     TIME+ COMMAND
  10.    6874 root      20   0 4782568 417876 109132 S  18.8  10.9   4:11.82 gnome-shell
  11.    7852 root      20   0  532420  42732  31144 S   2.0   1.1   0:17.06 gnome-terminal-
  12.    ......
  14. # 列出所有含有nginx字样的进程
  15. [root@myserver ~]# ps aux | grep nginx
  16. # 运行用户  pid   所占用各种资源----------------------------------------------------------
  17. root       40463  7.6  0.0 117748  2168 ?        Ss   14:51   0:00 nginx: master process /usr/sbin/nginx
  18. nginx      40464 33.2  0.2 149292  7936 ?        S    14:51   0:02 nginx: worker process
  19. nginx      40465  6.0  0.2 149292  7936 ?        S    14:51   0:00 nginx: worker process
  20. nginx      40466 46.8  0.2 149292  7928 ?        S    14:51   0:03 nginx: worker process
  21. nginx      40467 38.2  0.2 149292  7936 ?        S    14:51   0:03 nginx: worker process
  22. nginx      40468 15.3  0.2 149292  7916 ?        S    14:51   0:01 nginx: worker process
  23. nginx      40469 44.1  0.2 149292  7940 ?        S    14:51   0:03 nginx: worker process
  24. nginx      40470 32.5  0.2 149292  7940 ?        S    14:51   0:02 nginx: worker process
  25. nginx      40471 33.0  0.2 149292  7940 ?        S    14:51   0:02 nginx: worker process
  26. root       40479  0.0  0.0  12108   980 pts/0    R+   14:51   0:00 grep --color=auto nginx
  28. # 杀死40464号进程
  29. [root@myserver ~]# kill -9 40464
  31. # 检测是否杀死40464号进程
  32. [root@myserver ~]# ps aux | grep nginx
  33. root       40463  0.0  0.0 117748  3500 ?        Ss   14:51   0:00 nginx: master process /usr/sbin/nginx
  34. nginx      40465  0.0  0.2 149292  7936 ?        S    14:51   0:00 nginx: worker process
  35. nginx      40466  0.4  0.2 149292  7928 ?        S    14:51   0:03 nginx: worker process
  36. nginx      40467  0.3  0.2 149292  7936 ?        S    14:51   0:03 nginx: worker process
  37. nginx      40468  0.1  0.2 149292  7916 ?        S    14:51   0:01 nginx: worker process
  38. nginx      40469  0.4  0.2 149292  7940 ?        S    14:51   0:03 nginx: worker process
  39. nginx      40470  0.2  0.2 149292  7940 ?        S    14:51   0:02 nginx: worker process
  40. nginx      40471  0.3  0.2 149292  7940 ?        S    14:51   0:02 nginx: worker process
  41. nginx      40686  0.0  0.2 149292  7940 ?        S    15:05   0:00 nginx: worker process
  42. root       40689  0.0  0.0  12108   988 pts/0    S+   15:05   0:00 grep --color=auto nginx
  44. # 杀死40463号进程（nginx服务主进程）
  45. [root@myserver ~]# kill -15 40463
  47. # 检测是否杀死40463号进程（主进程被干掉，和nginx服务有关的运行进程全部被干掉）
  48. [root@myserver ~]# ps aux | grep nginx
  49. root       40737  0.0  0.0  12108  1100 pts/0    S+   15:08   0:00 grep --color=auto nginx
  51. # 查看当前nginx服务的状态，是关闭的
  52. [root@myserver ~]# systemctl status nginx.service 
  53. ● nginx.service - The nginx HTTP and reverse proxy server
  54.    Loaded: loaded (/usr/lib/systemd/system/nginx.service; disabled; vendor preset: disabled)
  55.    Active: inactive (dead)
  56. ......
  58. # 打开nginx服务
  59. [root@myserver ~]# systemctl start nginx.service 
  61. # 检测nginx服务是否被打开
  62. [root@myserver ~]# systemctl status nginx.service 
  63. ● nginx.service - The nginx HTTP and reverse proxy server
  64.    Loaded: loaded (/usr/lib/systemd/system/nginx.service; disabled; vendor preset: disabled)
  65.    Active: active (running) since Tue 2020-07-28 15:10:49 CST; 9s ago
  66. ......
  68. # 查看nginx服务有关进程
  69. [root@myserver ~]# ps aux | grep nginx
  70. root       41077  0.0  0.0 117748  2160 ?        Ss   15:32   0:00 nginx: master process /usr/sbin/nginx
  71. nginx      41078  0.0  0.2 149292  7932 ?        S    15:32   0:00 nginx: worker process
  72. nginx      41079  0.0  0.2 149292  7948 ?        S    15:32   0:00 nginx: worker process
  73. nginx      41080  0.0  0.2 149292  7956 ?        S    15:32   0:00 nginx: worker process
  74. nginx      41081  0.0  0.2 149292  7924 ?        S    15:32   0:00 nginx: worker process
  75. nginx      41082  0.0  0.2 149292  7960 ?        S    15:32   0:00 nginx: worker process
  76. nginx      41083  0.0  0.2 149292  7960 ?        S    15:32   0:00 nginx: worker process
  77. nginx      41084  0.0  0.2 149292  7960 ?        S    15:32   0:00 nginx: worker process
  78. nginx      41085  0.0  0.2 149292  7960 ?        S    15:32   0:00 nginx: worker process
  79. root       41115  0.0  0.0  12108  1060 pts/0    S+   15:33   0:00 grep --color=auto nginx
  81. # 杀死所有和nginx服务有关的进程
  82. [root@myserver ~]# killall nginx
  84. # 查看是否杀死成功nginx服务
  85. [root@myserver ~]# ps aux | grep nginx
  86. root       41149  0.0  0.0  12108  1032 pts/0    S+   15:33   0:00 grep --color=auto nginx
  88. # 查看杀死nginx服务有关进程后nginx服务状态
  89. [root@myserver ~]# systemctl status nginx.service 
  90. ● nginx.service - The nginx HTTP and reverse proxy server
  91.    Loaded: loaded (/usr/lib/systemd/system/nginx.service; disabled; vendor preset: disabled)
  92.    Active: inactive (dead)
  93. ......