React Native – Beginner’s Notes

Introduction As when I started working on React more than 1 year ago, I faced many noob issues that I think many newbies will also struggle with. Several weeks ago, …

Hadoop A Beginner’s Note

 NameNode (NN) NN holds the metadata of the files in HDFS, maintains the entire metadata in RAM It is important to run NN from a machine that has lots of RAM …

Upgrading Percona XtraDB Cluster

Guide can be found at https://www.percona.com/doc/percona-xtradb-cluster/5.7/howtos/upgrade_guide.html. There is no need to re-invent the wheel. I am too lazy to do it. Issue 1: If you are running mysql_upgrade and face the …

Setting up ReactJS Development environment with Babel and WebPack

This quick guide is to help you setup ReactJS Development environment with Babel and WebPack. The post is mostly copied from Source: https://www.codementor.io/reactjs/tutorial/beginner-guide-setup-reactjs-environment-npm-babel-6-webpack. I post it here for later personal reference. …

OpenVPN installation quick tutorial

Just a quick introduction for OpenVPN installation since there is a good work from https://github.com/Nyr/openvpn-install that helps install in 1-click. I just add some extra notes when installing as well as connecting for …

Install OpenVPN server CentOS 7

Today I will brief necessary steps for installing OpenVPN server CentOS 7. This will include custom server name and also rules for csf firewall which is widely used. The OpenVPN server …