进学斋 Jinxuezhai

I tested several tools try to manage node.js versions. Finally, I found that a tool called n (https://www.npmjs.com/package/n) was really useful. N is a Node.js version manager. It allows you to easily install, update, and uninstall different versions of Node.js. It also allows you to switch between different versions of Node.js with ease. N is a great tool for developers who need to work with multiple versions of Node.js. Install n. curl -L https://git.io/n-install | bash Those are some useful commands: n <version> n latest n update n -s latest n uninstall <version> n uninstall latest

In the morning, I noticed somebody wants to visit our host. They tried so many usernames and passwords. I used a command to check the records of visit: lastb -100 So many records displayed on the screen. We can install fail2ban to protect our host. For centos yum install epel-release yum install -y fail2ban systemctl enable fail2ban # check Fail2ban's status fail2ban-client status # check Fail2ban's status of sshd fail2ban-client status sshd # check Fai2ban's version fail2ban-client version # check Fail2ban if run or not fail2ban-client ping # start Fail2ban fail2ban-client start # stop Fail2ban fail2ban-client stop # restart Fail2ban fail2ban-client restart # open Fail2ban's log tail -f /var/log/fail2ban.log

Yesterday, I found an error message from a log file. The error message as below:   The group member's supported protocols are incompatible with those of existing members I had search it from google website. when I searched this web page https://stackoverflow.com/questions/55371819/nodejs-kafkajsprotocolerror-the-group-members-supported-protocols-are-incomp Based on the best answer I modified group id from "a" to "b" in the configuration file. So, the consumer application running very well. As you can see, connect and consumer should use different group id.