Programmer Group

These days when I started hadoop, I didn't even mention the installation of hadoop distributed cluster in the video. I started to talk about the concept directly. After thinking about it for a few weeks, I still solved it. There are too many small problems and the data are messy. The blogs speak differently. I have to summarize and find out the ...

1. Cluster distribution file Application scenario We often need to copy the newly created and modified files to the same directory of all nodes. It is not so friendly to execute the scp command once. Basic knowledge (a) rsync command original copy: [root@bigdata801 hadoop-3.3.1]# rsync -av /opt/module/hadoop-3.3.1/ bigdata802:/opt/module/h ...

1, New user access [avoid using names such as sshd that conflict with service built-in accounts] In general, for the sake of system access security, the system administrator account will not be directly used for remote access. 2.1 creating users With administrator privileges, execute cmd, execute user addition instructions, and creat ...

Guangdong Mobile HM201 TV box (Nanchuan license plate) brushes the route beside armian + docker + openwrt Box information: S905L, 1G+4G, 100m network port, USB2.0x2, 2.4G WiFi (not driven under armbian), no Bluetooth Input under the built-in Android system terminal: cat /proc/device-tree/amlogic-dt-id Results obtained: gxl_211_1g 1, U S ...

IDEA remote deployment debugging Java application Basic overview In our work, we may encounter that we cannot connect to the development environment database and other resources locally, but we want to develop and debug directly locally. At this time, it can be realized through the Run on... Function of IDEA. The principle is to connect ...

Deep understanding of Linux file system and log analysis 1, inode and block overview File data includes meta information and actual data Files are stored on the hard disk. The minimum storage unit of the hard disk is "sector", and each sector stores 512 bytes Block Eight consecutive sectors form a block Is the smallest u ...

Openssh 1, Introduction to Openssh OpenSSH is a free open source implementation of SSH (Secure SHell) protocol. SSH protocol family can be used for remote control or transfer files between computers. The traditional methods to realize this function, such as telnet (terminal emulation protocol), RCP, FTP, rlogin and rsh, are extremely insecure, ...

Java developers must have come into contact with the Linux system, so many times during the development process, we break our project into a jar package or war package, upload it to the specified directory of our server through XFTP, and then run the startup script at one end, Make our project accessible, like. / sh service.sh start, and then s ...

(vlunerable practice) – Node penetration practice Download address http://www.vulnhub.com/entry/node-1,252 This article is a reference to the boss Orange lady Written in my article The following are my notes following his article Scan host (netdiscover) sudo netdiscover -i eth0 -r 192.168.100.0/24 Target host IP: 192.168.100.152 ...

catalogue preface SSH Main functions of ssh server configuration file ssh Remote Login mode Service configuration scp remote replication sftp Secure FTP The sshd service supports two authentication methods Password verification    Key pair verification TCP Wrappers access control Two implementation methods of protection ...