【案例分析】Linux下怎样查看port占用情况
2017-08-12 10:15 tlnshuju 阅读(227) 评论(0) 编辑 收藏 举报作者:zhanhailiang 日期:2014-11-08
基于express写一个測试server代码例如以下,可是执行失败,报“listen EADDRINUSE”。字面上理解是error address in use,说明当前你监听的port3000已经被使用了:
[root@~/wade/wadetest]# cat index.js var express = require('express'); var app = express(); app.get('/', function(req, res){ res.send('hello world'); }); app.listen(3000, function() { }); [root@~/wade/wadetest]# node index.js events.js:72 throw er; // Unhandled 'error' event ^ Error: listen EADDRINUSE at errnoException (net.js:904:11) at Server._listen2 (net.js:1042:14) at listen (net.js:1064:10) at Server.listen (net.js:1138:5) at EventEmitter.app.listen (/root/wade/wadetest/node_modules/express/lib/application.js:559:24) at Object.<anonymous> (/root/wade/wadetest/index.js:8:5) at Module._compile (module.js:456:26) at Object.Module._extensions..js (module.js:474:10) at Module.load (module.js:356:32) at Function.Module._load (module.js:312:12)
尝试使用netstat查看当前机器port占用情况:
[root@~]# netstat -anop Active Internet connections (servers and established) Proto Recv-Q Send-Q Local Address Foreign Address State PID/Program name Timer tcp 0 0 0.0.0.0:6379 0.0.0.0:* LISTEN 5906/redis-server * off (0.00/0/0) tcp 0 0 127.0.0.1:11211 0.0.0.0:* LISTEN 8023/memcached off (0.00/0/0) tcp 0 0 0.0.0.0:6380 0.0.0.0:* LISTEN 26815/redis-server off (0.00/0/0) tcp 0 0 0.0.0.0:80 0.0.0.0:* LISTEN 2720/nginx off (0.00/0/0) tcp 0 0 0.0.0.0:22 0.0.0.0:* LISTEN 23854/sshd off (0.00/0/0) tcp 0 0 0.0.0.0:3000 0.0.0.0:* LISTEN 6732/node off (0.00/0/0) tcp 0 0 127.0.0.1:9000 0.0.0.0:* LISTEN 2466/php-fpm off (0.00/0/0) tcp 0 0 0.0.0.0:3690 0.0.0.0:* LISTEN 25447/svnserve off (0.00/0/0) tcp 0 0 0.0.0.0:3306 0.0.0.0:* LISTEN 23376/mysqld off (0.00/0/0)
当中:
-n, --numeric don't resolve names -p, --programs display PID/Program name for sockets -a, --all, --listening display all sockets (default: connected) -o, --timers display timers
由上可见。port3000被PID为6732的node进程占用。
接下来通过ps查询该进程的具体信息:
[root@~]# ps -f -p 6732 UID PID PPID C STIME TTY TIME CMD root 6732 6703 0 Nov02 ? 00:00:00 node /root/wade/git/node-lessons/lesson1/app.js [root@~/wade/wadetest]# ps -fp 6703 UID PID PPID C STIME TTY TIME CMD root 6703 1 0 Nov02 ? 00:00:00 pm2: Daemon
当中:
-f full 表示输出进程完整信息,如上所看到的 -p by process ID 表示查询指定进程ID
最后。kill掉进程6703或停止pm2服务就可以正常执行上面的node演示样例:
[root@~/wade/git/node-lessons/lesson1]# pm2 kill [PM2] Stopping PM2... [PM2] Deleting all process [PM2] deleteProcessId process id 0 [PM2] All processes has been stopped and deleted [PM2] PM2 stopped [root@~/wade/wadetest]# node index.js
例如以下图: