Networking
有哪些選項可以正確關閉手動埠或釋放 rhel 機器上的埠？
我們有 redhat 7.5 伺服器
我們懷疑埠 50070 沒有被服務正確關閉，（我們通過 netstat 和 PID 未找到）但是從日誌中我們可以看到埠正在使用中
因此我們嘗試執行以下操作，例如
ss --kill state listening src :50070 ss: unrecognized option '--kill' Usage: ss [ OPTIONS ] ss [ OPTIONS ] [ FILTER ] -h, --help this message -V, --version output version information -n, --numeric don't resolve service names -r, --resolve resolve host names -a, --all display all sockets -l, --listening display listening sockets -o, --options show timer information -e, --extended show detailed socket information -m, --memory show socket memory usage -p, --processes show process using socket -i, --info show internal TCP information -s, --summary show socket usage summary -b, --bpf show bpf filter socket information -Z, --context display process SELinux security contexts -z, --contexts display process and socket SELinux security contexts -N, --net switch to the specified network namespace name -4, --ipv4 display only IP version 4 sockets -6, --ipv6 display only IP version 6 sockets -0, --packet display PACKET sockets -t, --tcp display only TCP sockets -u, --udp display only UDP sockets -d, --dccp display only DCCP sockets -w, --raw display only RAW sockets -x, --unix display only Unix domain sockets -f, --family=FAMILY display sockets of type FAMILY -A, --query=QUERY, --socket=QUERY QUERY := {all|inet|tcp|udp|raw|unix|unix_dgram|unix_stream|unix_seqpacket|packet|netlink}[,QUERY]但 ss 不包括殺戮標誌
什麼是正確關閉埠或釋放 rhel 機器上的埠的選項？
日誌是：
2020-07-18 21:26:22,753 INFO impl.MetricsSystemImpl (MetricsSystemImpl.java:shutdown(606)) - NameNode metrics system shutdown complete. 2020-07-18 21:26:22,753 ERROR namenode.NameNode (NameNode.java:main(1783)) - Failed to start namenode. java.net.BindException: Port in use: linux.gg.com:50070 at org.apache.hadoop.http.HttpServer2.constructBindException(HttpServer2.java:1001) at org.apache.hadoop.http.HttpServer2.bindForSinglePort(HttpServer2.java:1023) at org.apache.hadoop.http.HttpServer2.openListeners(HttpServer2.java:1080) at org.apache.hadoop.http.HttpServer2.start(HttpServer2.java:937) at org.apache.hadoop.hdfs.server.namenode.NameNodeHttpServer.start(NameNodeHttpServer.java:170) at org.apache.hadoop.hdfs.server.namenode.NameNode.startHttpServer(NameNode.java:942) at org.apache.hadoop.hdfs.server.namenode.NameNode.initialize(NameNode.java:755) at org.apache.hadoop.hdfs.server.namenode.NameNode.<init>(NameNode.java:1001) at org.apache.hadoop.hdfs.server.namenode.NameNode.<init>(NameNode.java:985) at org.apache.hadoop.hdfs.server.namenode.NameNode.createNameNode(NameNode.java:1710) at org.apache.hadoop.hdfs.server.namenode.NameNode.main(NameNode.java:1778) Caused by: java.net.BindException: Address already in use at sun.nio.ch.Net.bind0(Native Method) at sun.nio.ch.Net.bind(Net.java:433) at sun.nio.ch.Net.bind(Net.java:425) at sun.nio.ch.ServerSocketChannelImpl.bind(ServerSocketChannelImpl.java:223) at sun.nio.ch.ServerSocketAdaptor.bind(ServerSocketAdaptor.java:74) at org.mortbay.jetty.nio.SelectChannelConnector.open(SelectChannelConnector.java:216) at org.apache.hadoop.http.HttpServer2.bindListener(HttpServer2.java:988) at org.apache.hadoop.http.HttpServer2.bindForSinglePort(HttpServer2.java:1019) ... 9 more 2020-07-18 21:26:22,755 INFO util.ExitUtil (ExitUtil.java:terminate(124)) - Exiting with status 1 2020-07-18 21:26:22,757 INFO namenode.NameNode (LogAdapter.java:info(47)) - SHUTDOWN_MSG: /************************************************************ SHUTDOWN_MSG: Shutting down NameNode at ************************************************************/ [root@linux hdfs]# [root@linux hdfs]# [root@linux hdfs]# netstat -tulpn | grep 50070 ( no PID number is returned )
一個開放的網路套接字就像一個文件句柄：一旦持有該句柄的程序退出，該套接字肯定是關閉的。所以我建議以下（以root身份執行）：
ss -tulpn | grep ":50070"查看結果（如果有的話），看起來與此類似：
Netid State Recv-Q Send-Q Local Address:Port Peer Address:Port udp UNCONN 0 0 0.0.0.0:68 0.0.0.0:* users:(("dhclient",pid=1670,fd=6)) udp UNCONN 0 0 127.0.0.1:323 0.0.0.0:* users:(("chronyd",pid=1540,fd=1)) udp UNCONN 0 0 [::1]:323 [::]:* users:(("chronyd",pid=1540,fd=2)) tcp LISTEN 0 128 0.0.0.0:22 0.0.0.0:* users:(("sshd",pid=1583,fd=3))如果您發現一個程序保持埠打開，請使用 kill 命令將其殺死：
kill <pid>但是由於持有開放埠的程序是一個服務，我真的建議你考慮其他關閉埠的方法：
systemctl stop <service>- 停止服務，一旦它退出，打開的埠也消失了……- 修改服務的配置不打開有問題的埠
- 使用防火牆拒絕訪問此埠