Programmer Think

1. Vim automatically adds annotations and intelligently changes lines #vi ~/.vimrc set autoindent set tabstop=4 set shiftwidth=4 function AddTitle() call setline(1,"#!/bin/bash") call append(1,"#====================================================") call append(2,"# Author: lizhenliang") call append(3,"# Create Date: " . strftime("%Y-%m-%d")) ...

Deployment DNS Forward Resolution Main configuration file (/etc/named.conf): Used to define the operation of the bind service program. Zone Profile (/etc/named.rfc1912.zones): The location where the corresponding relationship between domain name and ip address is stored. Similar to the catalogue of books, it corresponds to the specific ...

One of the most common problems in Travelling is that the site is slow or inaccessible, and what you see on the server is that the site is CC***.CC*** is one of the DDos*** types, and ** users use a large number of "chickens" to initiate requests to the site they are targeting, which is so frequent that the servers of the site they a ...

TCP Wrappers TCP Wrappers is a firewall-like mechanism managed by two files /etc/hosts.allow /etc/hosts.deny Not all software can be managed through these two files, only the following two software can manage firewall rules through these two files: Services managed by super daemon (xinetd) Services supporting libwrap.so m ...

LVS test report test plan Basic Function Testing Flow pressure test Response time test Configuration Correctness Test Disaster Recovery Testing Test points Basic Function Testing Client IP Address Correctness Real Server Access Internet Tests (including Iptables Rule Priorities) Flow pressure test Flow peak t ...

1. Linux Operating and Maintenance Experience Sharing and Troubleshooting 1.1 Basic Strategy and Experience of Online Server Installation Streamlined installation strategy: Installation only required, on-demand installation, no need not not install Development package, basic network package, basic application package 1.1.1 CentOS-6.x 1.1. ...

Remote Access Control / The two files, etc/hosts.allow and/etc/hosts.deny, control remote access by which a client of an IP/IP segment can be allowed or prohibited to access Linux. sshd:172.25.254. :spawn echo `date` from %c to %s >> /dev/pts/1 iptables Summary: Linux packet filtering software. Three watches and five chains ...

1. Introduction to analog delay transmission Netem and tc: netem are a network simulation function module provided by Linux 2.6 and above. The function module can be used to simulate complex Internet transmission performance, such as low bandwidth, transmission delay, packet loss and so on, in a LAN with good performance. Many distributions o ...

Configuring LVS services requires at least four nodes server20.com 172.25.23.20server21.com 172.25.23.21server22.com 172.25.23.22server24.com 172.25.23.24 iptables selinux on each node needs to be turned off and iptables startup is prohibited; Start by installing the httpd service on server22.com and server24.com. [roo ...

10.19 iptables rule backup and recovery service iptables save saves rules to/etc/sysconfig/iptables Iptables-save > target file Save rules to another file [root@arslinux-01 ~]# iptables-save > /tmp/ipt.txt [root@arslinux-01 ~]# cat !$ cat /tmp/ipt.txt # Generated by iptables-save v1.4.21 on Wed Apr 17 19:56:24 2019 *filter :INPUT ACCEP ...